The kombucha brewing jar provides a controlled brewing environment with built-in ventilation. Kombucha is an effervescent, tangy tea that’s both delicious and good for you. It’s made by fermenting sweetened tea using a kombucha culture, which ‘digests’ the sugar in the tea, thus generating the wealth of vitamins, antioxidants, and probiotics that make it the nutrient-packed living drink it is. Air goes in and out through the jar’s cloth filter. This is the first-ever fermentation crock to be designed specifically for kombucha brewing. It comes complete with its own filter and tap valve and allows you to brew and store your own kombucha at home. The rewritable label at the top of the crock makes it easy to identify each batch, while the booklet provides plenty of delicious recipes. The interior of all Mortier Pilon crocks and jars is 100% glass. The white parts on the outside of the crocks and jars are made of non-reactive, BPA-free plastic, and do not come into contact with the food.