Ask The Brewmasters

Hey Scott,

I'm glad you posted this question because we have been trying to find an answer to this issue for a very long time.

We currently centrifuge all of our barley wine and imperial stouts before racking to barrel. Before we installed the fuge, we would rack into barrels after a soft crash which could sometimes lead to yeasty and soy saucy character in finished beer. More importantly, we used to use biofine post aging and would often end up with a gelatinous coating that could be up to an inch thick in the bottom of the brite that you could pick up in your hand like a piece of jello! We still had the haze in those beers.

We have tried centrifuging pre and post barrel aging as well as post aging cold crashing, biofining, and then centrifuging- all with little to no effect. We no longer see much beer jello, but the haze continues.

In the book Wood and Beer by Cantwell and Bouckaert, they talk about lignin and tannins in oak being affected by the acidity of beer and note that seasoning and charring breaks down these compounds making them more accessible. My educated guess is that these compounds somehow combine with malt and/or hop compounds and make a wicked haze forming super molecule that, in really high quantities, turn into beer jello. (citation needed)

Maybe using some sort of post aging tannin reducing agent would help? I can't seem to find much information in the wine world about targeting oak tannins specifically.

I'd love to hear others thoughts and experiences here. 

Hey Scott,

A couple questions come to mind. First off, how are you racking the beer out of the barrels? I assume you're using a goosneck but wanted to be sure.

Second, is it possible that whoever is racking the beer is allowing yeast and/or sediment from the bottom of the barrel to get racked into your packaging tank? (I ask that without judgment: having racked my fair share of barrels using a gooseneck, it's not always easy to tell when you're about to get to that layer of sediment on the bottom.)

Finally, I agree with you about feeling reticent to filter those beers. With that in mind, I would argue that your best bet is to go through your brewing process to find the source(s) of the haze.

Also, would you be open to using clarifying agents?

Hey Scott, thanks for the follow up! In terms of haze, if we're assuming it's chill haze (which it might not be), I would argue that just because your other beers don't have clarity issues does not mean that there aren't aspects to your brewing process that don't lead to chill haze in barrel aged beers. A lot is happening during barrel aging: oxidation, evaporation, esterification, and extraction from the barrel just to name a few. During that time it's possible that reactions are occurring in the beer that are linked to the brewing process. Since your regular beers don't go through that process, it's plausible that the aged beers could have chill haze linked to the brewing process while the regular beers do not. 

Similarly, haze can form due to proteins combining with polyphenols. Even if the polyphenol content of your beer is low, it's possible that polyphenols are being extracted from the wood of the barrel, leading to haze. I bring this up because it comes back to the brewing process and the question that comes to mind is: do you use irish moss, whirlfloc, or something similar? Related to that is the protein content of the barley used for this batch of beer: what is the protein content of the barley used to make this beer? Could it be that it was unusually high (i.e., even though your brewing process didn't have issues, higher protein content of the inputs resulted in this haze)?

One other thing comes to mind: in whiskey production, if the alcohol content becomes too low during maturation, there are compounds that are insoluble in water and if the alcohol content of the whiskey becomes too low those compounds form a haze. Considering that even strong beers are relatively low in ABV compared to whiskey, it's unlikely that alcohol reduction is the source of your haze, but it could be that compounds were extracted from the wood and that those compounds are not water soluble, leading to the haze.

Also, @Jonathan Porter makes a great point about the interaction of wood tannins and lignins not playing nice with the acidity of beer.