Can I drink kombucha while pregnant? As with everything pregnancy-related, the Google searches are conflicting.

—Probiotic-deprived mama

Googling around on this is, indeed, frustrating. This is one of the classic examples where websites say things like “Kombucha might be safe during pregnancy, but it’s best to avoid it just in case.” In case what? In case the baby gets two heads? In case it makes you pee too much? Let’s have some more concrete information here.

In practice, there are three concerns with kombucha: alcohol, caffeine, and listeria. Let’s take them one at a time.

Caffeine: Kombucha has a very minimal amount of caffeine. As I have discussed extensively in Expecting Better and elsewhere, there is no reason to fear even moderate amounts of caffeine, such as what you’d have in coffee. The caffeine levels in kombucha are not a significant concern.

Alcohol: Kombucha is fermented, which means it has some alcohol content. For most commercial kombucha products, it is extremely low — typically less than 0.5% alcohol by volume. At this level, it is considered non-alcoholic (it’s a similar alcohol level to what you’d get in a non-alcoholic beer). Even if you take a very conservative stance on alcohol in pregnancy, this level is so limited that there really isn’t anything to suggest it would cause any problems.

One note of caution is that if you are brewing your own kombucha at home, the alcohol content could be significantly higher. It may be sensible to consider store-bought kombucha during this period.

Listeria: Kombucha is unpasteurized. This means it carries a risk of listeria, similar to soft cheeses. Listeria is very dangerous during pregnancy, but it’s also very rare. Further, there aren’t any significant listeria outbreaks linked to kombucha in the past many years (outbreak list here — this doesn’t include all cases, just the major outbreaks, which are recently linked to salad and chicken). The unpasteurized nature of kombucha makes it a possible risk.

In Expecting Better I describe listeria as “harmful but hard to avoid,” meaning not that it’s common but that it’s not clear how much your actions impact your risk of getting it. Many listeria cases happen seemingly at random — salad, bean sprouts, cantaloupe, ice cream — and the decrease in risk from avoiding any particular food like kombucha is very small. The reality is that different people will make different reasonable choices about it. Obviously, in all of this, there is a question of degree. If you are drinking four liters of kombucha a day, that may be an issue, pregnant or not.