Our friends at Anheuser-Busch have long told us that their flagship brand Budweiser is "beechwood aged." What exactly does that mean to us?
Well, they do use beechwood chips in their lagering process. The purpose is not to add any beechwood flavor, in fact they boil the chips before they add them to their aging tanks to remove any oils or resins that can impart flavors. The purpose of the chips is to increase surface area on the bottom of their tanks where the chips settle. Suspended yeast in the beer will then settle onto this arrangement of beechwood chips allowing more yeast cells to be in contact with the beer during aging.
What's the benefit of contact with these yeast cells? During active fermentation, yeast produces many flavor compounds. Some of these compounds are desirable in the final product, others are not. After active fermentation and when in the process of going dormant and preparing for their next batch to ferment, yeast cells will draw in those undesirable compounds, thus removing them from the finished beer as they are filtered out. A couple of these compounds we are concerned with are acetaldehyde (green apple flavor) and diacetyl (buttery and butterscotch flavor) the latter being most troublesome in lagers because of lower fermentation temperatures. So when you can increase the amount of contact between aging beer and the yeast, post-fermentation, by having yeast cells collect on all these beechwood chip surfaces instead of a single layer on the bottom of the tank you can speed up the diacetyl removal process, thereby shortening aging time and moving the beer to the consumer faster.
Next up is "fire brewed" the old Stroh's line.
never trust The Sober Brewer