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.