Kefir and Kombuch, as fermented products, are considered to be Halal in general. According to Islamqa for milk kefir and Kombucha (click on underlined links): Where the concentration of alcohol in the drink is very small, in such a way that it will not cause intoxication no matter how much a person drinks of it. This concentration has no effect, and this drink is halaal. There is no evidence in Islam to suggest that the mere presence of a small concentration of alcohol in a drink – no matter how small it is – makes the drink haraam. Rather the hadith quoted above indicate that the reason for the prohibition is intoxication; therefore whatever drinks cause intoxication are haraam, and whatever does not cause intoxication is halaal.Please note that fermented products in general (not just kombucha and kefir) contain trace amounts of alcohol as a byproduct. For example: kimchi, soy sauce, tempeh etc. Overconsumption of these fermented products are unlikely to lead to intoxication.Craft & Culture's production kitchen, while not Halal-certified, produces only fermented products and fermented brews--we do not process pork, lard and alcohol within our kitchen premises.