4-Vinyl guaiacol (4VG)

clove-like, spicy, or herbal – breaks down over time to create vanilla flavor

clove-like, spicy, or herbal – breaks down over time to create vanilla flavor

Source: yeast through decarboxylation of ferulic acid. Ferulic acid can be increased through a mash rest at 45 or warmer sparge water.

Expected in Bavarian Weizens and many Belgian beers.