Written by the team of Rabbanim from the Orthodox Union:

Rabbi Eli Gersten, Rabbi Yaakov Luban and Rabbi Moshe Zywica

Do foods that are certified vegan require hashgacha? Since these foods cannot contain meat, fowl, or fish, can it be assumed they are kosher?

No, such an assumption is unfounded.

First, although the manufacturer or restaurant claims to be vegan, it is halachically questionable whether one may accept as fact claims made by companies for their own benefit. Igeros Moshe (Even Ha’ezer 5:42 and see also YD 1:55) writes that one can only rely on ingredient statements if the company would face government fines if the information were found to be untrue.

Second, vegan foods can be non-kosher even if they do not contain meat, fowl, or fish. A vegan food may have a status of bishul akum (foods cooked by a non-Jew that can be served to a distinguished guest and could not have been eaten raw), which is not kosher.

Vegan foods may also contain non-kosher wine or wine vinegar, as well as fruits and vegetables that are prone to infestation. Although many vegans will not eat insects, their standard for inspection may not meet halachic requirements.

Finally, if the product was cooked with non-kosher utensils, it would not be acceptable even if all the ingredients were kosher.