While glass is the preferred and safest material for kombucha fermentation due to its non-reactivity, food-grade stainless steel can also be used. Avoid ceramic vessels unless you are absolutely certain the glaze is lead-free and food-safe.
Kombucha is an acidic beverage, and the acidity can react with certain materials, potentially leaching harmful substances into your brew. This is why the choice of fermentation vessel is crucial.
Glass: Glass is non-reactive, meaning it won't interact with the kombucha's acids. It's also easy to clean and sterilize, and you can visually monitor the fermentation process. This makes it the ideal and most commonly recommended material.
Stainless Steel: Food-grade stainless steel is also non-reactive and safe for kombucha fermentation. However, it's essential to ensure it's truly food-grade, as lower-quality stainless steel might contain alloys that could leach into the kombucha. Avoid using stainless steel vessels with any signs of rust or pitting.
Ceramic: Ceramic vessels are generally not recommended unless you are absolutely certain the glaze is lead-free and food-safe. Many ceramic glazes contain lead, which can leach into the kombucha due to its acidity. Lead contamination can be dangerous, so it's best to err on the side of caution and avoid using ceramic unless you have specific documentation confirming its safety for food use. Even then, hairline cracks in the glaze can harbor bacteria.
Always sanitize your fermentation vessel thoroughly before each batch of kombucha to prevent mold or unwanted bacteria from contaminating your brew. Use a food-grade sanitizer or a solution of vinegar and water.