Written by Mitch Codd /// Illustrated by Francesca Cosanti
No matter how much headspace I give my rye ferments, it seems like I’m always stuck cleaning up the foam-over mess in the morning on Day 2 . What are some tricks to making this less painful?
DEAR STICKY MESS, Rye whiskey can be really frustrating to produce, which is a bummer because it tastes so great! The composition of the grain itself is unlike all the others we typically use, lending to its rough reputation, lower yields, and sticky, foamy, thick messes. While we could dive deep into rye’s interesting peculiarities, let’s focus on a few practical solutions for your troubles. Most of the solutions I’ll propose target the viscosity of the mash to ease these troubles. We typically break viscosity in two ways: enzymes and dilution. Since dilution means more water content and therefore lower sugar content, we also end up with lower ABVs. Typically, you will see rye whiskies starting around 17 degrees Brix or so, whereas a bourbon is in the mid 20s without any issues. Since we usually 108
don’t want to run our fermentations any lower in ABV, further dilution is probably out of the question. Enzymes come next. These wonderful little pieces of biological machinery are integral to our process, whether we get them from a bottle or from the malted barley in the grain bill. We typically focus on two enzymes, alpha-amylases (AA) and gluco-amylases (GA) to do our conversion from starch to sugars. If the AA can’t do its job fully, we can end up with a partially converted mash, with thick dextrins and starch complexes making a thick mash to ferment, prone to low yields and foam-overs. It’s really important to be sure you have the right temperatures and times, as well as pH levels to get the most out of those enzymes in your cook.
Assuming the AA and GA enzymes are doing their job, the next thing to look into is the enzyme that breaks down the “unique” components of rye grain: beta glucans (BG). These non-starch, soluble fibers are difficult to work with and need their own niche enzyme to break them down. This BG enzyme is typically added into the water before grain goes in and rested around 150 degrees F to get an efficient break. I also prefer to see a second addition and rest after we take the grains to higher temperature for the AA rest, as it can further reduce viscosity, increase yields, and speed cooling efficiency. A lot of the times I troubleshoot messy rye fermentations, the cause is a suboptimal BG rest. Despite my confidence in the BG enzymes’ amazing powers, it’s worth noting that the fermentations can still be difficult, even
with efficiently broken beta glucans and starch complexes. The next tool in my tool belt is also an enzyme but a pretty cool one: a protease. Using a protease, preferably just after the second BG enzyme addition, can destroy the proteins that are inherent in the grain, degrading down into small peptides and amino acids. These proteins can be responsible for foam that is difficult to “pop” and remains structurally sound while fermentation is going. If we break those proteins down, we end up with a much weaker foam layer, and it doesn’t reach as high in the fermenters and spill out. The beautiful part of this is that the product of protein degradation is amino acids, and our yeast cells LOVE amino acids. They are a healthy source of organic nitrogen, and they allow our yeast to be more efficient, higher yielding, and create better flavors. Proper use of a protease can be quite powerful for your production and keep it much cleaner. The last few tools I would test in this situation are much more W W W . ARTISANSPIRITMAG . C O M