It is well known that ester formation in beer is mainly a factor of temperature. Higher fermentation temperatures produce more esters. (Other factors play a role as well, such as the yeast's genetic proclivity to ester formation, pitching rates and dissolved oxygen (DO) levels, but if these are considered equal, temperature is the primary controlling factor.)
Lately I have been brewing some Belgian ales with POF+ Belgian yeasts, which causes me to wonder: is the formation of spicy phenols also temperature-related?
(Once again other factors in POF formation play a role here, the most well-known one being the presence of ferulic acid in Weizen worts, which is decarboxylated into 4-Vinyl guaiacol during fermentation. However, this phenol is only a minor one among the desirable volatile spicy phenols typically produced by Belgian yeasts.)
I understand that phenols are produced early in the fermentation cycle, whereas esters are produced later from fatty acids and higher alcohols. However, Belgian fermentations typically start cool in order to keep the higher alcohols in check and prevent a "hot" or harsh alcohol character, and are then ramped up. Pitching warm and starting the fermentation warm can create an excess of sharp and "hot" fusels but I haven't noticed an increase in spicy phenols in these cases. Which suggests that the formation of these spicy notes in POV+ yeasts is not significantly temperature related.
Is this correct?
If so, what factors govern the amount of volatile spicy phenols in Belgian ales and how might they be manipulated to vary the amounts of volatile spicy phenols produced?