Yes, really! We are going to talk chicken grit today. No, no, don’t turn your back on this Blog Post! Believe me: it has everythiing to do with craft distilling. Or better: with craft fermenting. Here we go.
Many of my recipes contain backset. As does most American whiskey. Let’s rephrase that. Most American whiskey uses backset, or stillage, and so do my recipes.
Backset is what remains in the boiler after a strip run: a mix of water, cooked yeast, grain particles, and some higher boiling point alcohols. If you add backset to a new ferment, it will add taste, nutrients, and general sourness.
It’s the sourness that may cause problems. And that’s where chicken grit has a role.
Over multiple generations of stripping and re-using backset for another fermentation cycle, the backset – and hence the ferment – gets more and more sour. PH values, that already drop significantly during a normal fermentation, without backset, tend to get even lower, when backset is part of the recipe.
Yeast, nature’s own little alcohol factories, works well in certain environments and less well in others. As far as sourness is concerned, yeast likes to live in an environment that’s between 6.0 PH and 7.5 PH (reference: 7.0 PH is neutral, most tap water is 7.5 to 8.0 PH).
Higher (sweeter) or lower (sourer) PH values hamper and eventually damage the yeast. That’s because yeast cells can only adjust their internal PH by 0.2 PH, relative to the PH value of the environment they live in.
Under too sour conditions, their energy production fails and the capability to turn almost all 6C sugars into ethanol alcohol and CO2 becomes less. In short: if your ferment is too sour, the efficiency (speed) and effectiveness (what’s produced) suffer. Longer fermentation times (or even stalled washes) and too many lower and higher boiling point alcohols are the unwanted results.
I have seen washes with backset take longer. And when I measured for sourness, I found values as low as 3.05 PH. That’s like putting yeast in hell, and – at the same time – stating that you expect them to be fully committed and dedicated to the job at hand.
So if sourness, caused by the repetitive use of backset, is the problem, what’s the solution? The solution is chicken grit.
Chicken grit is made from (mostly) sea shells. And sea shells are produced by small sea living animals creating a lime based shelter for themselves. Lime? Calcium carbonate, that’s how it is called in scientific terms!
Calcium carbonate highers PH levels. Bigger amounts of lime AKA calcium carbonate in your mashing and fermentation water, give that water an improved buffering capability. PH won’t drop so fast. PH won’t drop so deep.
Why not use calcium carbonate as is, to raise PH? It is available in pretty much all brew shops. Why go for chicken grit instead?
- The general rule, that calcium carbonate dissolves easier in more sour circumstances, off course applies to both calcium carbonate powder and chicken grit.
- But chicken grit has much less surface area. Where calcium carbonate powder dissolves easily, chicken grit does not.
- Chicken grit, or actually the broken shells it is made from, does not dissolve in neutral environments. Otherwise there wouldn’t be much shell fish left in the oceans, right?
- But the more sour a wash gets (and fermentation is a souring process in itsself), the more calcium carbonate will dissolve from the shells.
- So if your wash turns very sour, chicken grit will up its performance. And if your wash isn’t that sour (anymore), it will throttle back.
The essential difference between a calcium carbonate powder and chicken grit is that with chicken grit you can hardly overshoot and make the mash too sweet. It self-regulates its activity, based on the actual PH values in your fermentation. That’s KISS in my dictionairy!