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How to Ferment Oats – A Probiotic Recipe

probiotic recipes - How to ferment oats featured image

Oats contain antinutrients, and you wan’t rid of ’em! This recipe lets you maximise nutrient content, probiotics, and flavour… Read on and discover how to ferment oats!

Contents List:

Helloat there! Wow I couldn’t have started this in any better way, huh? Moving on… Today, we ‘re going to discover how to ferment oats.

Oats have made big news in the world of nutrition, including their fame for fueling athletes.

For a long time, people have savoured them as a healthy part of their diet (even daily). I am one such person.

I LOVE oats!!! As a kid, most people will have memories of growing up eating them as porridge or oatmeal, and that applies to me too. I remember the times before school when I would wake up with a warming bowl of oats on a winter’s morn.

That was always nice…

Now it’s even better. Fermented oatmeal (it’s better than it sounds) makes a much tastier and healthier traditional meal! You’ll be saying the same after this.

Why to Eat More Oats!

These delicious grains contain a host of wonderful health benefits and are a great source of fibre, complex carbohydrates, protein, and even healthy fats. Studies have shown their brilliant potential for nutritional health benefits.

Nutritionally they are very rich in minerals, most notably magnesium, manganese, and phosphorus, but also iron, copper, and zinc. This is amazing for proper growth, healthy organs, immune function, detoxification, blood sugar control, lowering LDL cholesterol, lowering inflammation, and much much more!

Not only that but they are good sources of fibres such as beta-glucans, antioxidants and vitamins B1, B5, and B9.

Most of the time, people stick to “instant oats”, you know the ones that come in packets (or boxes) that you mix with a little milk and microwave for 2 minutes?

Well I used to too… Until I started to dive into the deep sea of study on nutrition.

For most people, these instant oats are a healthier alternative food for breakfast. And compared to something like pancakes or biscuits they certainly are.

However, eating oats in this way in large quantities has its drawbacks, and today you will discuss why that is and a very easy workaround. This wholegrain recipe will open a world of flavour and nutrition, give it a try.

The ‘Original’ Oats – A Humble History

It is thought that the earliest cultivated oats came from what is present-day Switzerland during the period of the Bronze Age. That’s at least over 3,000 years ago!

Since that time they have travelled the seven seas, become dietary staples and gained cultural significance across the world.

Thankfully, despite high amounts of unsaturated fats, oats naturally have a lengthy shelf life due to the presence of antioxidants. These include antioxidants such as Avenanthramides and Phenolic Acids. These protect the fats from oxidation (and thus distortion).

In the days before instant oats, it was common wisdom (and in fact written on the early oat boxes) to soak oats at least overnight before consuming them. And in fact this has seen a resurgence recently. This increases digestibility, nutrition, and creates a slightly more wholesome and tasty meal.

Some of you might already know why this is, but in the next part I’ll be explaining why fermenting your oats is a much more nutritious way of preparing them with many added benefits.

Knowing how to ferment oats is also a great skill for other similar fermentation processes.

Fermented Oats – Why Ferment as Opposed to Eat Raw?

For beginner, easy things to ferment, there isn’t a much better starting place!

As I said, many people soak their oats overnight with the intention of increasing digestibility and nutrition. This popular meal is known as “overnight oats”.

Whilst these overnight oats are better than raw, oftentimes the intended benefits are not as effective as we would like.

This is especially true of overnight oats soaked in the refrigerator, where the temperatures actually inhibit the actions we want!

In short, the reason that soaking oats is beneficial is due to the reduction of so-called “anti-nutrients”. These inhibit our natural digestive processes and in high amounts may be related to several adverse effects.

How Do Anti-nutrients Work?

The main concern is ‘phytic acid‘. This is a chemical compound stored in plant seeds with two main purposes:

  1. To provide the seedling of a plant with energy and phosphorus.
  2. To protect the seed’s stored fats, proteins, and nutrients. 

It does so by binding to minerals such as iron, calcium, zinc, and magnesium, thereby strengthening and toughening the seed. This way, it will not be broken down fully if ingested by many animals.

However, this binding “traps” the minerals! Essentially, it prevents us from absorbing them during digestion.

Are “Overnight Oats” Healthy?

Overnight oats are all the craze, with some brilliant recipe ideas out there. But, they often aren’t as beneficial as they’re made out to be! Here’s why…

The thought process behind “overnight oats” or “soaked oats” is that the naturally present enzyme phytase will be “activated” and break down the phytic acid.

P.S. I went into more detail on this subject in my last post about Why to Soak Nuts if you are interested.

Oats, however, have very low levels of the phytase enzyme naturally present within them.

So “overnight oats” without the addition of a high-phytase (and even probiotic) food source like apple cider vinegar, rye flour, or whey will achieve little nutritional result.

Furthermore, a common mistake is putting the oats in the fridge for the duration of the process, which will strongly prevent enzyme activity.

The key: aim for sourdough oats. This means fermented, much like traditional flour!

Since I’ve known how to ferment oatmeal, I’ve never looked back. The flavour is so much more complex, as is the nutrition. Plus it’s fun!

What Fermentation Does, in a Nutshell!

To truly boost the nutrition of oats is to take things a step further by fermenting. Trust me, it’s very easy! This will produce an amazing yeasty, slightly sour flavour and a creamy texture.

how to ferment oats, lacto fermented oats recipe healthy ronin day 3

The fermentation process will not only allow for high levels of phytase activity, but it will also encourage the activity of many beneficial bacteria naturally present on the oats.

These bacteria will feast on the starches and sugars in the oats. They are vital for a healthy immune system, and for the microbiome (this is the collection of trillions of bacteria and enzymes – our gut flora – present largely in our digestive system).

A healthy microbiome is important in allowing us to break down food and produce healthy biological compounds, absorb nutrients, prevent infection, modulate mood and aid in brain health, and much more.

P.S. There is an entire developing field of science and study dedicated to the microbiome and I highly suggest you read about it. It’s very fascinating!

The beneficial bacteria in fermentation are what we refer to as ‘probiotics’.

Probiotics are living microorganisms which provide us with many health benefits when ingested! They feed on so-called prebiotics’ for fuel, and as luck would have it, oats are loaded with these! Prebiotics are mostly insoluble fibre.

What’s more, other antinutrients such as amylase inhibitors’ will be reduced by fermentation. That’s great news for us!

This is where we find out about the two different recipe methods most commonly used to ferment oats. Each takes about 5 minutes of work in total.

Great! Now let’s see just how to ferment oats…

Tips for How to Get Started

Fermenting oats is something that I used to do practically every day. I will eat my oats often between 10am and 12pm, or whenever have my body tells me that I’m hungry, and set some more on the shelf for the next 2 or 3 days to ferment.

If you want to eat oats regularly, this is a good way to go about it.

Because of this, I’ll sometimes be using two bowls and two small tea dishes to cover them. Some people prefer to use jam or preserve jars covered with a tea towel or cheesecloth in a dark place, and really it’s down to your preference.

Method 1 – The Wild Method

The first way how to ferment oats it’s very easy. This is the method that I use the most as I personally prefer the results that it yields, and also find this easier and cheaper.

I’d recommend using a water filter for the best results and to save time.

How to ferment oats probiotic wild fermented oats method 1 wild method

Fermented Oats (Wild Method)

James Mcdonald
A simple probiotic recipe with no starter cultures! Slightly sour, deeply delicious, and oh-so nutritious.
5 from 1 vote
Prep Time 5 minutes
Fermenting Time 2 days
Total Time 2 days 5 minutes
Course Breakfast, Dessert, Main Course
Cuisine British, International
Servings 1 person
Calories 220 kcal


  • Bowl / Container (fermentation-safe – See notes)
  • Small Dish, Tea Towel, or Cheesecloth (to cover container)
  • Tablespoon
  • Pestle and Mortar optional


  • 60 grams Oats Groats or steel-cut are best, but any type will do
  • 2 tbsp Apple Cider Vinegar Organic, probiotic types are perfect, but once again, any will do if it's pure
  • 120 ml Tepid Water boiled and cooled or filtered to remove chlorine


Preparing the Oatmeal

  • Grind the oats and add to the bowl. Any method will work (even clean hands), as long as it releases the starches.
    Grind the Oats - Ground organic whole oats How to Ferment Oats
  • Add your tepid (chlorine-free) water to the bowl. This should ideally be room-temperature to lukewarm, but not hot.
  • Stir in 2 tablespoons of apple cider vinegar.
    step 2 add the ingredients - How To Ferment Oats - A Probiotic Recipe
  • Place bowl in a warm place. The countertop or – especially in winter – somewhere like on top of your fridge.
  • Cover with your dish or cheesecloth.
    Step 4 Cover bowl and keep warm to ferment - How To Ferment Oats - A Probiotic Recipe


  • Check the oats and stir daily. This stage takes on average 1 to 3 days for optimal results.
  • Always keep the oats fully submerged.

Digging In!

  • Eat uncooked or cooked. Simply strain, add water or milk of your choice, season, and cook as normal!
  • Scroll down for recipe ideas!


IMPORTANT: Read the safety notice further in the post – this is a fermented product so proper precautions are a must.
The instructions for this recipe are almost identical to the first method.
To dechlorinate water: You can use a Water Filter (See Recommendations) or simply boil the water to remove the chlorine.
Make sure you let it cool to a lukewarm temperature before you use it, otherwise the heat will kill the beneficial bacteria and denature the phytase.
For the container: Remember, you should use ceramic, china, stainless steel 316, glass (but keep in a dark place), or Polycarbonate, PP, HDPE, or LDPE Plastic containers only.
Other plastics and metals will react with the acidity and interfere with the natural processes of fermentation. For example, non-steel containers will rust, and plastic may leech.


Keyword Fermentation, Probiotic, Wholegrain

The reason I call this ‘The Wild Method’ elaborates on step 5 above. By allowing a natural flow of air, not only wild yeasts present on the oats, but also in the air will lend a hand in fermentation.

Another important reason for allowing a flow of air is that as the bacteria digests the starches and sugars in the oats they will produce carbon dioxide. This is the gas which will cause bubbles on the surface of the water and it will need a way to escape the container so pressure doesn’t build up.

Can Yeast Ferment Starch? Will this Lower Carbohydrates?

Wild yeasts feed off of glucose, primarily. This means that the starches (complex carbohydrates) in oats are not broken down by yeast directly.

However, this does not mean that the carbohydrate content won’t decrease.

During the early stages of fermentation, enzymes break down carbohydrates into more readily available forms (sugars) such as glucose and fructose. This leads to a temporary increase in sugar content.

Notice I said temporary. It gets more interesting now, because towards the end of the first 24-hour period, the beneficial bacteria start to feed off of this and the overall carbohydrate content decreases.

Over longer periods, more of the free sugars will naturally be used up.

This effect has been observed in multiple studies(^), such as This One on Pearl Millet.

All the while, antinutrients are being reduced, and the amount of nutrition we can absorb is being boosted. This means a better source of proteins, minerals, and vitamins.

So can yeast ferment starch? Not directly, but in these fermented oats they play an important role in nutrient composition.

Once Again, This Will NOT Work without Dechlorinated Water…

The easiest way to achieve this (and healthier, fresher water in general, is with a water filter). Here’s our guide to the best water filters for every purpose – from kitchen countertop to portable, and more between.

Boost Your Fermenting (and Water Quality) > The Top Water Filters For Drinking Water – Top 5 For Every Purpose!*

*(P.S. Here are my #1 and #2 recommendations).

Method 2 – Lacto-Fermentation

Our second method when knowing how to ferment oats depends on a probiotic source to kickstart the fermentation process.

This means beneficial strains of bacteria are used, as you’ll see.

How to ferment oats probiotic lacto fermented oats method 2 lacto-fermented

Lacto-Fermented Oats

Probiotic, creamy oatmeal using live cultures from whole ingredients!
5 from 1 vote
Prep Time 5 minutes
Fermenting Time 2 days
Total Time 2 days 5 minutes
Course Breakfast, Dessert, Main Course
Cuisine British, International
Calories 250 kcal


  • Bowl / Container (fermentation-safe – See notes)
  • Small Dish, Tea Towel, or Cheesecloth (to cover container)
  • Tablespoon


  • 60 grams Oat Groats or steel-cut are best, but any type will do
  • 2 tbsp Lacto-fermented Probiotic / Live Yoghurt, Kefir, or Buttermilk You can also use dairy-free alternatives
  • 120 ml Tepid Wate boiled and cooled or filtered to remove chlorine


Preparing the Oats

  • Grind the oats and add to the bowl. Any method will work (even clean hands), as long as it releases the starches.
    Grind the Oats - Ground organic whole oats How to Ferment Oats
  • Add your tepid (chlorine-free) water to the bowl. This should ideally be room-temperature to lukewarm, but not hot.
  • Stir in 2 tablespoons of live yoghurt (or your other probiotic source).
    How to ferment oats probiotic lacto fermented oats method 2 lacto-fermented
  • Place bowl in a warm place. The countertop or – especially in winter – somewhere like on top of your fridge.
  • Cover with your dish or cheesecloth.
    Step 4 Cover bowl and keep warm to ferment - How To Ferment Oats - A Probiotic Recipe


  • Check the oats and stir daily. This stage takes on average 1 to 3 days for optimal results.
  • Always keep the oats fully submerged.

Digging in!

  • Eat uncooked or cooked. Simply strain, add water or milk of your choice, season, and cook as normal!
  • Scroll down for recipe ideas!


IMPORTANT: Read the safety notice further in the post – this is a fermented product so proper precautions are a must.
The instructions for this recipe are almost identical to the first method.
To dechlorinate water: You can use a Water Filter (See Recommendations) or simply boil the water to remove the chlorine.
Make sure you let it cool to a lukewarm temperature before you use it, otherwise the heat will kill the beneficial bacteria and denature the phytase.
For the container: Remember, you should use ceramic, china, stainless steel 316, glass (but keep in a dark place), or Polycarbonate, PP, HDPE, or LDPE Plastic containers only.
Other plastics and metals will react with the acidity and interfere with the natural processes of fermentation. For example, non-steel containers will rust, and plastic may leech.


Keyword Fermentation, Probiotic, Wholegrain

This method makes use of the live bacteria (namely of the genus Lactobacillus) present in the yoghurt, kefir, or buttermilk.

These bacteria are renown for their benefits to gut health and are used extensively in many fermented food products. This is where we get the term “lacto-fermentation”. They are also often present naturally on the surfaces of vegetables and fruits.

These lacto-fermented oats may have a more tangy flavour than those from the other method. Many people enjoy this as a pleasant difference.

You may even like to refrigerate the oats the day or night before you eat them. That way, you can enjoy them chilled, much like you might sour cream (and yes, they will be creamy)!

Food Safety: How to Ferment Oats Safely

Enjoying the wonderful creations we can produce through fermentation is extremely rewarding. As such, we want to do it right.

There are a couple of safety points that are important to keep in mind when making oats this way. To prevent any unwelcome bacteria or fungi, stay safe, and spot when things aren’t right, here’s what to know:

  1. Use clean equipment. You don’t want to use anything that you haven’t washed first, as this could cause cross-contamination.
  2. Use your senses. If the scent or taste is not pleasantly yeasty and slightly sour – and especially if it is unpleasant and not as described – discard the batch and try again.
  3. Look out for mould. If you see any mould or suspected mould (this could be any colour), do not simply scrape it off and eat the oats, as mould has roots. Discard the batch and try again.
  4. Learn to spot kahm yeast*. This is a wild yeast that may appear on top of your ferment. It’s totally safe to skim off, and often appears as more of a translucent film. Here’s a quick link to learn more (article by Fermenting for Foodies). It should not look “fluffy” or resemble mould in any way!
  5. Don’t be discouraged. A ferment going wrong happens to almost everyone who does it often at least once.
  6. Be positive! It will likely be fine, but should you have to restart, take it as a learning experience and don’t give up! These oats are delicious, healthy, and well worth the effort.

*(Take a look at the recipe photos – the thin layer on top is after 3 days, and is what the starch / yeast may look like)

Remember the above, and as long as you keep your oats submerged, there shouldn’t be any problems.

How to Eat Fermented Oatmeal – Recipes and Suggestions!

When you are ready to try your newfound amig-oats (yes I did), you can simply drain them, add your favourite healthy ingredients, and enjoy! Also, you can add a little milk or water and microwave for 2 to 3 minutes. Easy!

You don’t even have to cook them, and can enjoy a nice chilled breakfast. More on that in a bit…

As for recipes – the only limit is your imagination! … Okay, and maybe what ingredients you actually have.

I personally am I massive fan of savoury oatmeal. You can literally use oats just like other grains, even rice or pasta; it’s a dreamy food combination that so many miss out on!

How do you eat savoury oats? Here are ‘3 IRRESISTIBLE Savoury Oatmeal with Cheese Recipes’ to get you started!

If you prefer to mix in more typical foods like fruits, nuts, seeds, chocolate, etc., don’t worry, I’ve got you covered. Take a look at my ‘5 Best Oatmeal Recipes for Breakfast’!

Eat Them “Raw” for More Probiotics!

For those who’ve ever wondered how to eat oats without cooking, this is the perfect method.

Oftentimes I have my oats half uncooked and then heat the rest. This is because heating / microwaving will kill the bacteria, so the benefits are reduced.

However, studies have shown that even dead probiotic bacteria benefit our immune system).

If you want to do this often, whenever you eat the oats, set some more for fermentation and mix in 1 or 2 tablespoons of the previous batch to kick-start the process!

Don’t think this is all there is to fermented oats, though. I’ve prepared mine in so many fun and creative ways that work wonderfully and most probably wouldn’t even think of (see above for examples).

Time needed: 2 days and 5 minutes

Summary How-To for Fermenting Oats

  1. Grind your oats if whole (at least coarsely).

    This can be done using a coffee grinder, pestle and mortar, clean hands, or even the end of a rolling pin. This step helps to release the starches from inside the oats.

  2. Add the ingredients.

    Pour your oats into your chosen container. Next, pour the dechlorinated / tepid water in with the oats, making sure to submerge them fully. Only do this after making sure that your water is cooled to a lukewarm or room temperature (or possibly warmed if you Use a Water Filter). Add the 2 tablespoons of apple cider vinegar (or probiotic source).

  3. Cover the container.

    Cover the container with a cloth or loosely with a small dish. You want to make sure that a little air can get in and out. Remember, you should only use ceramic, china, stainless steel 316, glass (ideally kept in a dark place), Polycarbonate, PP, HDPE, or LDPE Plastic containers.

  4. Leave to ferment.

    Stand (preferably somewhere warm) for 1-3 days. This will depend on your climate – a warmer environment is more ideal for fermentation. Stir once or twice a day. You’ll know it’s ready when it takes on a yeasty and sour scent and produces bubbles.

  5. Finally, check in and wait.

    Check for safety! If the scent or taste is not pleasantly yeasty and slightly sour – and especially if it is unpleasant and not as described – discard the batch and try again. This could be a bad sign of unwelcome bacteria that we do not want to be eating!

    If you see any mould or suspected mould (this could be any colour) DO NOT simply scrape it off and eat the oats as mould has roots. Discard the batch and try again. You may get some starches or yeasts from the oats rise to the surface of the water, producing an extremely thin filmy layer. This is perfectly safe. It should not look “fluffy” or resemble mould in any way!

Have you ever soaked or fermented your oatmeal before? Let me know of your experiences, or if you tried this, how did you find it? 🙂

I hope to have given you some insight into the world of probiotics, and that these recipes work well for your new ventures!

If you enjoyed this and learned something new about how to ferment oats, you might also enjoy our other posts.

Until the next one, stay healthy


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51 Replies to “How to Ferment Oats – A Probiotic Recipe”

  • Hi James,
    This is really very interesting. My family takes oats every day for breakfast, we typically cook it in water. Now I know there is a much better and healthier way to eat it – ferment first! But I really have no confidence in it, as I may not know how to discern properly fermented oats and oats that have turned bad because maybe I did something wrong. I will still give it a try though. Start small.

    Thanks for this very informative article.

    • Hi there Joo, I’m glad to hear that you’ve learned from this post 🙂
      When it comes to fermenting oats, as long as you keep them under the water it should all be fine! If it goes off, chances are you’ll know straight away. Remember it shouldn’t smell unpleasant or look like it has any mold, and you should be all good!
      Best of luck with your oats! Once you get a taste for it I’m sure you’ll want more haha
      Have an awesome day,

      • Hi James, thanks for reminding me of this most important tip: keep them all under water. I will make a small portion for myself first. If it is successful, I will then scale it up for the family, haha.

  • Hi , thanks for this info… do you know if it’s important to drain the oats? I just did it for the first time and since the liquid seems to be basically oat milk I thought why drain it. Also, how long is the max u can keep it (refrigerated?) Thanks in advance!

    • Hi there, thank you for reading and leaving a comment! Those are both very good questions.

      When it comes to draining the oats, you could skip the step if you wanted to, (or even drain the water and keep it). The oatmeal generally will taste better without it, or with some milk instead. The water itself will provide a good source of probiotics and minerals in particular. Note that it might be quite sour as we add acidic ingredients.

      This should last covered for up to a week in the fridge, but in theory may last a few days more. It depends on your fermentation speed, storage, and temperature. Try to make sure it’s thoroughly drained and covered, just to be sure 🙂

      I haven’t done this myself, so will give it a try! Thank you for sharing.

      Best of luck,

        • Yep, you’ve got it! 🙂 In addition, the decreased pH and acidic environment is what will stimulate the enzymes necessary to break down the plant’s antinutrients, such as phytase. The result is thus a more digestible oatmeal and a ferment that is better “protected” from pathogenic bacteria.

  • Hi James,

    This is a great article with tons of information! I usually have one relatively large bowl of oats every morning, with some added cinnamon and honey. I’ve never tried fermented oats though, so I’m going to give it a try! Thanks again!

    Have a great rest of your weekend!

    • Thanks for reading, Kevin! I appreciate the comment.

      Cinnamon is great with oats, right! Since I’ve been fermenting oats, I’ve discovered that their amazing flavour can be so much more than most people realise. I’m sure you’ll enjoy your fermented oats, best of luck! Remember to have fun – be creative.

      Why not have a try?
      (P.S. Always make sure to follow the guidelines)

      Enjoy your week!

  • Hi, I am making oat milk. How do the large manufacturers make theirs sweet? The ingredients don’t include a sweetener so I wondered if they use a process? Any advice would be much appreciated.

    • Hi there, great question! If you’re fermenting your oat milk, then you’ll naturally end up with a more yeasty or sour taste – depending on your method. Large manufacturers tend to stick to around a 10:1 ratio of water to oats, and don’t ferment. For a closer flavour without using raw oats, here’s what I’d recommend:

    • Try sprouting oat groats – this has some similar nutritional benefits to fermenting by breaking down antinutrients, but won’t have the same effect on flavour
    • Dilute your mixture for a milder result
    • Use a similar 10:1 ratio when fermenting and keep the water (skim off yeast or starch from the surface)
    • The most common options with oat choices are whole, steel-cut, or rolled*. I’d always recommend whole or steel-cut oats. They’re less processed, so retain more flavour and nuttiness and contain more nutrients. However, rolled will provide a milder and less nutty flavour, which may help to emphasise the natural sweetness instead.
      (*Oat groats are healthiest but less available).

      Hopefully this will help. Let me know if you have any more questions, and also how it goes if you try these methods out! 🙂

      Best of luck,

  • 5 stars
    Hi, have you also tried fermenting at 42 degrees (for example Yogurt maker)? Maybe you’ll have the same result within 12-24 hours?

    • Good question! As a matter of fact, I haven’t measured the temperature for my ferments yet. Fermenting your oats for even that amount of time will still help to improve the nutrition either way, especially if you use a starter from a previous batch to get things going and you can maintain a warmer environment.

      As I continue to try new ferments, a yoghurt maker does seem inevitable eventually. If you try this, let me know how it goes! 🙂

      Thanks for commenting, (and have a Happy New Year!),

      • Hi James,
        So my experience with Yoghurt maker at 42 degrees…😄. I made my fermenting last night. Nice texture, very tasty. Like very much!!! My new experience will be adding probiotics (CGN 30 billions one capsule, IHERB). Hope the result will be ok.

        • Hey there Raimundo, it’s great to hear back from you!
          That sounds excellent, especially if the oats had already fermented and became bubbly or yeasty. I’ll have to try this myself when the time comes, haha. Good thinking with adding probiotics as a starter, it seems like a great way to get things going. Just remember that by adding the probiotics, the wild yeasts won’t be as dominant. 🙂
          Best of luck!

  • This is how I do it: 1 cup organic rolled oats (Whole Foods Market bulk), 1 cup water. Cover with coffee filter. Store in cabinet 48 hours. Use half to make breakfast, store 2nd half in fridge for next day. Cook low heat. After starting to cook, time for 7 minutes, stirring frequently. After using what’s in the fridge I rinse out the pint Ball jar I use ( Do Not wash) and start a new batch. No apple cider vinegar, no yogurt, nothing. It is gonna ferment just fine. It is its own starter. Plenty of bacteria available on the dry oats. You will know it has worked by the sweet smell of the fermentation. Organic is important. Non organic oats are dried in the field using glyphosate.

    • Thanks for sharing your method with us here.
      Effectively, you’ve created a reusable starter for your ferment, which can be reused in batches just like the recipes here! The reason I add the extra ingredients (especially in the ‘Wild Method’) is to provide the oats with enough enzymes to effectively break down antinutrients such as phytase, and to kickstart the process that little extra. Essentially, it’s a method to feed the desired natural processes anything the oats themselves might lack!
      This isn’t necessary with most ferments, such as Brown Rice, but I do think it has more value when it comes to oats.
      Couldn’t agree more that organic is the best way to go. 🙂 (I only use organic oats myself!)
      Keep on fermenting!

  • Hi Robin, what pre/probiotics is produced from oats? Is this contraindicated with candida overgrowth or might it crowd out candida?

    • Hi there Lisa, James here. That’s an excellent question! I’ll break it down into three parts for you, so it’s easier to understand.

      Fermenting oatmeal can produce a variety of probiotics, and without testing the oats and the batch, it’s hard to know exactly which.

      This is especially true if you use the wild method, which depends on bacteria naturally present on the oats and on wild yeasts. And what these are would depend on the oats used, where they are from, and the area your ferment in.

      However, Lactobacillus strains are guaranteed. Many of these have similar health benefits for digestion and the immune system, and oat fermentation can support thousands of different types! Research has shown that Lactobacillus plantarum increases particularly well when oats are fermented(


      *). *(As can beneficial Koji mold strains, but these aren’t naturally found on oats).

      On the other hand, using a starter will provide more of the same probiotics as the starter itself. For example, if you use a yoghurt fermented with Lactobacillus acidophilus (as is common), that population will continue to grow as it ferments.

      In terms of prebiotics, oats contains several types of fibre which can feed healthy bacteria. Most oat fibre consists of beta-glucans, which are prebiotic and also have been shown to benefit heart health and cholesterol profiles, reduce inflammation, support healthy digestion, and more.

      If I read your question correctly, you’re asking about how the probiotics in fermented oats could affect someone with Candida overgrowth (Candida albicans)?

      I’ll try my best to give all the information I can, but please consider your individual situation as well. 🙂

      Unfortunately, I don’t know much about the topic of candida overgrowth, so I can’t give much advice. The best thing to do is to speak to your expert medical practitioner, and consult with a qualified personal nutritionist.

      From what I do understand, this is a complex subject and also may be different for individuals. Eating oats on a diet aimed towards treating the condition may be beneficial, especially if you can get gluten-free. However, there is concern that some wild ferments could aggravate the situation (whereas some people seem to have no problem, depending on the type).

      Given that fermented oatmeal is not a particularly common food (including as a wild ferment), specific research on the effects it could have on candida is limited, if any.

      Additionally, it’s recommended to avoid high sugar foods. Whilst fermentation will not make oats “high sugar”, the content will nonetheless increase.

      Overall, I’d recommend speaking to a professional and finding out how to sprout your oats instead (don’t worry, it’s simple). This will increase digestibility and reduce anti-nutrients, whilst preventing any potential adverse effects from the wild yeasts.

      I hope this helps! Sorry I couldn’t be more specific. Let me know if this is the information you were looking for, thanks!

      Best wishes,

  • Hello!
    Thanks for this post… What I still don’t get is the consistency result… I cannot use it for muffins or pancakes right? Or should I dry them in the oven before using them like I used to? (that would be the raw version)
    I only consume oats for that or to make milk

    • Hi there Carmen, that’s a great question! There are several ways you can go about cooking muffins or pancakes (or indeed other delicacies) with fermented oats.

      If you require a thicker dough / batter after fermenting and straining, you can try blending it to your desired consistency, adding eggs or a natural thickening agent such as chickpea or rye flour as necessary. However, you certainly can go about drying the oats in the oven, as well! That way you can use them even as toppings or to make a flour, but make sure they’re well-drained first, and preferably lay them on a mesh rack (if possible) so you’re not effectively baking them in any liquid.

      If I remember correctly, one way I’ve used them before is to mix the drained oats with eggs (one per bowl), add 1/2tsp baking powder, mix in any water / milk to make a dough, season as desired, and bake in muffin trays. Lovely little treats! 🙂

      Hope this helps! Thanks for your comment,

  • Hello,

    Love your article on fermented oats.  I’ve actually been seeing this more lately on social media and I didn’t know it was a big thing until reading your article. 

    A lot of the people I’ve seen doing this are putting the oats in the fridge; but like you said, things can’t ferment in the cold, so makes sense to leave them out in warm temps.  

    I like your overall layout, wording, etc.  I also like your popup to subscribe – I’m going to have to look for that and see how I can get that.  Nice touch!  

    Overall, love this!  Great job and I’ll actually read more of your posts!


    • Hello Katrina,

      Thank you for such a wonderful comment! It’s great to hear directly from a reader about the website itself, so I really appreciate your feedback on what you liked. 🙂

      Also they are indeed gaining popularity, but mostly as “overnight oats”, which – although better than raw oats – don’t offer all of the benefits that fermenting does, and still aren’t easy to digest for some people.

      Either way, welcome to the Healthy Ronin community – here’s to a healthy future and more content to come!

      Best wishes,

  • Hellooo der! After reading your article I feel like saving it so as to come back for future referencing, I dont know much about what youve said though but I believe this mini guide is really useful, I actually read it to the end because your choice of words and writing skills is really something to save and come back for future referencing. I really do fancy these post a lot, it really has made my day fun, thanks a lot for the info, it has been the best so far.

    • Hellooo!

      Thanks for such a nice comment – what a nice way to start the day!

      It really makes me happy to read that you enjoy the writing style here. I always like to engage readers and my goals is to make content that’s both fun and educational, so receiving that exact feedback means a lot! 🙂

      I’m glad you found the info helpful, let me know if there is any way I can help with any questions.

      Best wishes,

  • Hello there thanks for the review it was really helpful. t’s important to soak oatmeal prior to preparation. Doing so increases the digestibility of oats as it does and it enables the nutrients found in the grain to be better absorbed by your body. Oats, like all grains, contain phytic acid which can inhibit the proper absorption of minerals link zinc and iron.

    • Hi there,

      You’re absolutely correct! The truth is, this applies to all grains in general, and fermenting is one of the best ways to improve the way we can digest them and take up a lot more of the beneficial nutrients.

      Also, although soaking oats is now its own trend in the health and fitness industry, it often doesn’t have the effects we really want. One reason is that people leave them in the refrigerator, which inhibits the chemical reactions we need for breaking down certain antinutrients.

      By soaking for longer and encouraging fermentation, we unlock one of the traditional pillars of a healthy human diet which is often missing (or lacking) in the “Western” world!

      Thanks for a great conversation Philebur!

      Best wishes and stay healthy,

  • Hi James
    I’ve making my overnight oat by adding the baby rolled oat and water with some chia seed and raisins in a covered jar then keep it in the fridge for a night. Does this mean that the fermentation is totally wrong or that’s no fermentation at all?

    • Hi there Nadya, great question!

      What you’re essentially creating is a version of soaked oats. These overnight oats are very popular, but are often claimed to be low in antinutrients and even be probiotic (such as if made with yoghurt). However, the cold temperatures of the refrigerator prevent phytase action, and by using normal water (if you aren’t using filtered or otherwise dechlorinated), fermentation is also prohibited, so there’ll be no fermentation.

      To answer your question, this means that there is unlikely to be any beneficial fermentation, and – unfortunately – the effect on antinutrients isn’t as great as we’d like. Overnight oats are definitely better than raw, and many find them easier to digest, but for more of the intended health benefits, traditional fermentation is the way to go! Other better options would include overnight oats left out rather than refrigerated or sprouted oats (plus, you can still refrigerate them after if you prefer a chilled oatmeal).

      Hope this helps, best wishes,

    • Hey Nadya, thanks for all of your wonderful questions!

      If you’re referring to what I called “sourdough oats”, this is the recipe! In all practicality, what we’re doing here with oats and what you would with flour to make sourdough is very similar, so it’s just a simpler way to think of it.

      However, if you’re looking for a good sourdough recipe in general, I can only recommend others I’ve used (we don’t have any on Healthy Ronin site right now). Take a look below and let me know if you need anything more:
      Spelt sourdough starter: Recipe by The Bread She Bakes
      Rye sourdough starter: Recipe by Weekend Bakery
      Complete sourdough starter guide and methods: Guide & Recipes by Cultures for Health

      There are many more great recipes you can find online, and it’s definitely worth having a browse! These are just ones I can personally recommend.

      Hope this helps! 🙂

  • 5 stars
    I love eating fermented rolled oats, and it’s so easy to make! I put 260 gms of organic rolled oats into a wide mouth quart canning jar, add ~500 ml of filtered water, cover with a piece of muslin held in place with a rubber band and put it on top of my fridge. It’s sour and soft and very tasty in about 48 hours.
    Have you tried wild fermenting any other grains like kamut or rye or pseudo-grains, like quinoa or buckwheat? I have an old hand grinder, so I can set it up and grind up whole grains myself. In fact, years ago, I used to grind up whole oats and ferment them, but fermenting rolled oats is so quick to start, it’s got me spoiled. I’m going to see if my local co-op still has organic rolled rye flakes that I could experiment with. Do you have any recommendations?

    • 5 stars
      I know I’m not the only one! ^_^ Fermenting oats is wonderful, isn’t it?

      That’s a fantastic question, and I can indeed confirm that this works with other grains and pseudo-grains! The science behind fermenting these is very much the same, and can be applied to rye, quinoa, and buckwheat, but also bulgur, amaranth, wild rice, and even brown rice… The list goes on. 🙂

      (Here’s my Fermented Brown Rice recipe – plus how to make it really effective)

      You have some great ideas Karen, definitely go for it! Rye is a high-phytase grain, so that’s an excellent choice. This means it won’t need any extra phytase source (such as ACV), although low-phytase (pseudo-)grains like oats and millet benefit highly from extra phytase in order to reduce phytates.
      Top Tip: If they’re toasted or roasted, the phytase is essentially “denatured”, so then an extra phytase source is beneficial (as described for the recipes above).

      To memory, I’ve tried brown rice, buckwheat, bulgur, rye (flour), red rice, brown rice. All work wonderfully, although you should still cook harder grains like brown rice or quinoa (you could even cook them and then ferment them with another probiotic source).

      As far as recommendations, mixing oats with buckwheat and fermenting them together is heavenly! Seriously, it’s this simple for a nutty, soured, and versatile recipe:

    • Mix oats and buckwheat in your preferred ratio (I go for roughly 60% oats, 40% buckwheat);
    • Grind or crush oats and buckwheat lightly to release starch;
    • Add to a fermentation-safe container
    • Add approximately twice the volume of the mixture of filtered water;
    • Stir in 2 tbsp apple cider vinegar;
    • Cover loosely for 24-48 hours;
    • Enjoy (cooked or raw)! My “top” toppings are (soaked) nuts, cacao powder or dark chocolate (sugar-free, ideally 100%), and cinammon or black pepper.
    • Hope this helps! I love your enthusiasm – go and experiment; it’s how the best recipes are made! Thank you for such a wonderful comment.

      Best wishes,

  • James, you mention to drain the oats before consuming. Intuitively I’m thinking that it would be ok to consume them without draining or rinsing. Is this step necessary? And is there a specific reason you give this direction?


    • Excellent question, Sean, thank you! I’ll update this in the post, but yes, you are absolutely right. The liquid is indeed safe to consume as long as your ferment hasn’t developed mould or other signs of bad bacteria – the same guidelines as the oats apply. Plus, it’s likely probiotic, containing the beneficial bacteria we’re after.

      The reason I suggest draining is so you can add your desired milk or water with less of the sour taste that the water may have.

      In fact, I myself often reserve a little or even cook the oats in the water they’ve fermented in, but you may wish to drain as necessary so that it cooks to your desired consistency. 🙂 I hope this helps!

  • 5 stars
    Hi James, I eat around 80 grams of oats a day so the amount you mentioned would not be enough so if i tripled the amount of oats each time i ferment would that work? and obviously i would need to triple the ingredients for the water and cider vinegar too? Thanks for the useful recipe, best one i’ve seen

    • Hi Guy, that’s a great question and you’re absolutely right!

      I presume you meant 180 grams (60 * 3) is the amount you’re after, so you could absolutely triple the ingredients. However, this may take a little longer to ferment well, especially for a first batch without any bacterial culture from previous oat ferments. If you keep adding a tablespoon or so from your ferments to new batches, the process will definitely speed up as the probiotic cultures “mature”, so by all means go for it!

      Personally, I’ve played around with amounts and ratios, too, and the most important factors are: Keeping it covered and the oats submerged, adding enough (not too much) phytase from cider vinegar, rye, or a probiotic source, and being patient. 🙂 Hope this helps!

      Thanks for commenting and good luck, feel free to ask any more questions.

  • 5 stars
    Hi James
    This post was super interesting and informative.
    If I add plant based Phytase enzymes from rye flour or fermented yogurt does it work in the ph level of the fermented oat groats?

    • Hi there Ronit! Thank you for your comment. My sincere apologies for the delay in responding.

      The pH Level of the fermented oats (groats or other) should always be acidic in Lacto-fermentation, so either method will produce similar results and an acidic pH. The biggest differences between the two methods will be the inhabiting bacteria (one containing those from the fermented yoghurt and the oats, the other more so from the rye, oats, and wild yeasts), and perhaps the flavour slightly.

      I hope this helps! 🙂

  • Hi James, I have never fermented anything and was hesitant as I know nothing about it and didn’t want to make myself sick. But, on that note, I did soak my oats in filtered water, not warm because I read another recipe and it just said to add water. Then I only added a tsp of apple cider vinegar, a dash of salt and covered it with a lid that wasn’t permeable. Then the next day my oats had soaked up all the water but had that yeasty smell to them and seemed sour-like. I thought maybe this was a dangerous sign, but they were most likely perfect. I was hesitant to consume them so I put them in the fridge for a few days. This morning I brought them to a boil with more added water and had them for breakfast, but still being worried I only had a little bit. I know I did some things incorrectly from the beginning by not adding warm water and not leaving any air space. I cooked them to try to kill any bad bacteria that may have occurred, however, maybe this was the good bacteria that I killed. Are you supposed to eat them without cooking in this sour like state? There was the cloudy gooey film on them after I cooked them, is this too starchy or is this okay to ingest? I rinsed them thoroughly just in case. And then can you refrigerate the leftovers and cook them for the next day or is cooking altogether counterproductive to achieving the correct good bacteria? Or do you take out what you want to eat and leave the rest on the counter as is until they are consumed? Thanks for all your advice.

    • Vincetta, I know exactly how you feel! Every time I try new ferments, there are always questions. Tip number one: take a breather. Smile. 🙂 Fermenting is an art to be enjoyed.

      Now onto what you did well: Filtered water; apple cider vinegar (2 tbsp is advised for the amount of oats in this recipe); the salt is okay as long as there isn’t too much. All in all, you’ve got the basics down. And the smell you described seems right.

      However, there were some things that need adjusting: Add more water (the water should not all be absorbed, and the oats should always stay submerged, so aim for at least twice as much water as oats in weight); add more ACV (see above), let it breath – use a lid with ideally just a small amount of airspace (this allows for more free flow of wild yeasts, although you’ll still achieve fermentation in an airtight container, just “burp” it once a day to let gasses escape).

      When it comes to keeping them in the fridge, that technically wouldn’t make them any safer after a few days, as you’ll only be slowing fermentation and letting it go for longer.

      Cooking the oats is discussed in the post, where we learn that if all goes well, the probiotics are in the raw fermented oats and liquid. For this reason, I tend to sip some of the liquid and enjoy at least a tablespoon of the oats raw before cooking. That way, I enjoy the probiotic benefits and still get to eat hot, creamy oatmeal! 😛

      When you cook them (if you choose to), the heat will kill the beneficial bacteria and denature the enzymes. However, the benefits of greatly increased digestibility and a much more nutritious meal are still retained, so fermenting is still important even if we cook the oats – or any grain – afterwards.

      You also mentioned the “cloudy gooey film”. That’s perfectly normal, and is either starch or kahm yeast or both (which are safe, but you can skim off, and it is recommended to if it is kahm yeast). You can take a look at the recipe images to see what I’m talking about.

      Finally, if you want to retain the beneficial bacteria, you can just keep a tablespoon or so of the oats in a glass or jar in the fridge, and cover them with some of the fermenting liquid. They’ll likely last for at least a few days and then you can use them in your next batch to “kickstart” the process. Alternatively – and this is what I do because I very often have two bowls fermenting at a time – you can add some of the raw oats from the batch you want to cook to another batch that is fermenting, and then take the same amount back out of the other batch to “kickstart” the next batch you set to ferment (which will replace the one you’ve just cooked up!). Then you can just repeat this cycle between the different batches, essentially recycling and maintaining your very own live colonies of gut-friendly bacteria.

      Personally, I ferment only the amount I want to eat in a single batch, so I don’t have to take out different amounts of the oats each time I eat them and that way I can also avoid fermenting for too long. If you let it go for too long without feeding the batch with more oats, the bacteria will run out of food and die, and you also run the risk of allowing mould to develop later on. I would recommend trying this method if you can. 🙂

      Please let me know if this helps and if you have any more questions! Thanks for the fantastic questions and for reading this post (feel free to check out more to learn about fun and healthy eating).

      All the best,

  • I should be grateful if you could tell me if I could soya milk and dairy milk in equal proportions, instead of water, and then add Greek style yoghurt with the appropriate bacteria on the label. I would prefer this if it is possible, but concerned that there may be more danger of unwanted mould.
    Many thanks

    • Hi there Christopher, thank you for the question. Interestingly, I haven’t tried that method before, and my guess is that it would likely result in creating a yoghurt-like liquid at the same time.

      Unfortunately, however, I recommend that you don’t try to ferment the oats in mixed soya milk and dairy milk, due to several reasons. I will preface them by saying that you can indeed make home-made yoghurt with leftover live yoghurt and milk! A wonderful guide is laid out by Emillie of Fermenting for Foodies (recipe here).

      Regarding the oatmeal, firstly, soya milk often contains chlorinated water and vegetable / seed oils – both will prevent fermentation, and the latter is particularly bad for your health (see this post for more information). Not only that, but most soya milks are not from fermented or sprouted soya beans, meaning they retain a whole host of antinutrients and thyroid disruptors.

      Secondly, trying to ferment pasteurised dairy milk with this method does – as you mentioned – carry more risk. Dairy fermentation in general requires more thorough safety precautions and steps than this simple method of fermenting oats.

      For example, you’ll need to “scald” / heat the milk to 175-180˚F (79-82˚C) and cool it first before fermenting, in order to ensure any unwelcome bacteria are killed off and also to rearrange the milk proteins, which benefits the friendly bacteria. And you’ll definitely want to regulate temperature more for optimal results and safety. Additionally, it is likely that the milk – if it creates yoghurt – will mature before the oats, and then you could end up over-fermenting it and creating a much more sour taste than desired, or possibly end up with mould if left for too long.

      What could be a good idea is to create your home-made yoghurt and mix some oats into the liquid before it ferments. If you keep them submerged, the mould risk will be minimised, and the oats will ferment as well. This won’t give you a full serving of oats for the amount of yoghurt in a serving, but could be an interesting experiment. 🙂

      However, when we’re fermenting the oatmeal specifically, I’d advise sticking to water. It’s safer, more predictable, and you can always add your chosen milk after fermenting and draining. I sometimes even mix the fermented water with full-fat organic milk before cooking the oats, which retains the slight “tang” of the water. 😀

      I hope this helps, and wish you the best of luck in your fermenting journeys!

  • They also help kill off any harmful microorganisms that may be living within the gut. The word “bacterial” refers to a group of microorganisms. Probiotics have been shown to boost the overall health of the entire digestive system, including the gastrointestinal tract.

    • Very true, thanks for the point Darell! This is in part where the plethora of immune-boosting benefits of probiotics come from, and the fascinating part is that when we continually nurture and maintain a healthy gut microbiome through our diet and lifestyle, foreign invaders (the bad bacteria) are in turn continually fought off with greater efficacy! 😀

  • 5 stars
    Hi James,
    A really interesting article and discussion. Thank you for sharing your vast knowledge. May I ask about phytic acid? Every morning for decades I ate oatmeal porridge (conventionally cooked straight from the manufacturer’s packet) topped with live yogurt, fresh fruit and almonds. I thought I was being very healthy. Digestive problems and pain in my late 50s caused a big search for the cause, narrowed down eventually to whole grains and nuts: essentially seeds, which I (sadly) eliminated. Further reading about nuts and now your article makes me wonder if phytic acid was the culprit? Can it accumulate and damage the microbiome or even tissue? To make a long story short, I finally found the Zoe programme and think I’ve finally healed my microbiome – I can tolerate some seeds and whole grains and now want to try your fermented oats. I have a question and further comment: your recommended water filters link goes to a page now stored on the Wayback Machine. Do you have updated water filter recommendations? Also, referring again to Zoe, Dr Tim Spector talks about the differences between eating organic vs. industrially farmed plants of all kinds. He says in particular, oats make use of herbicides not just to keep down weeds, but to aid in the harvest: a particular herbicide is used to dry out and make oat harvest easier. Therefore oats not classed organic are significantly more heavily laden with chemicals than their organic counterparts. I’ve taken note! The ‘organic’ label is much more than a ‘lifestyle’ reassurance when it comes to oats. Thanks again for all your expert advice!

    • Hi Elizabeth,

      Great questions! Sorry to hear about your experience. Mine in fact was quite similar, so I know it’s frustrating to realise “healthy” foods are key culprits in causing problems – especially gut problems.

      Phytic acid doesn’t accumulate like other toxins, thankfully, at least as far as I am aware. However, phytic acid / phytates can lead to leaky gut and micriobiome changes: by inhibiting certain digestive enzymes and blocking vital minerals from being efficiently absorbed, the gut’s lining is weakened overtime due to undernourishment, and over time the micriobiome can indeed constitute to have more bacteria which break down a little more of the phytic acid / phytates; nevertheless, these anti-nutrients are not the most major health concerns for most people eating a nutrient-dense diet. There are many plant toxins (often found alongside phytic acid / phytates) that can cause direct damage to the gut and are implicated even in autoimmune disorders and poorer mental health. Lectins are the most infamous of these, and they’re also found in grains and legumes. Overall, it really is best to limit grains and legumes as much as possible… I’ve been dormant from this blog, but it needs a major overhaul if it is to continue.

      Regarding the water filter, I recommend any that will remove chlorine when it comes to fermenting: A distiller, reverse osmosis machine, or some water filter jugs will do the trick at reducing it! Also brilliant points about the importance of eating organic oats if you do decide to eat oats. There’s a vast difference between the quality of these two products. For me, before I gave up eating carbs as a whole (and believe me, I loooved oats! So it was hard but 1,000% worth it), I wouldn’t eat non-organic oats, and I recommend everybody else steer clear of them wherever possible. I hope this helps, Elizabeth!

      Wishing you all the best on your continued health journey. 🙂


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