Sourmash and yeast strains

[SmoothAmbler]

Not to kiss ass, but there's a reason many distillers, including me, call Todd Leopold for advice. That guy knows his stuff. It's pretty obvious from his post above.

[Leopold]

Appreciate the kind words, smooth ambler, but it sounds a lot fancier in print than it really is. Since I worked without a microscope as a brewer of lager beer for so many years, diacetyl reduction was one of the main guides I used for maturation.... in practice it was as complicated as "can I perceive butterscotch?" Which is about as simple a test as you get!

[bad_scientist]

Appreciate the kind words, smooth ambler, but it sounds a lot fancier in print than it really is. Since I worked without a microscope as a brewer of lager beer for so many years, diacetyl reduction was one of the main guides I used for maturation.... in practice it was as complicated as "can I perceive butterscotch?" Which is about as simple a test as you get!

Thanks for the superlative info! Most of my days are spent making and working with mutated mice, but in college it was all chemistry/pharmacology. Thanks for making me remember how much fun it can be!

[Leopold]

Indeed. It is probably one of Todd's explanations that explains the butterscotch quality of ND OT in the 70's and early 80's, but I guess we'll never know for sure.

What it does suggest too though (to me) is that "errors" can sometimes make fine whiskey...

Gary

Agree 1000% I would argue that it's all the little procedural imperfections that give beer/whiskey/whatever house flavor, and sometimes, to borrow a wine term, terroir. At our shop we do everything we can to produce house flavors and terroir.

As a modern distiller, for the most part select yeast that produce little or no diacetyl and attenuates fully. This way, you don't have to worry about needing the distiller's beer to long enough to for the yeast to reduce various maturation compounds.

The differences between beer and spirits fermentation are quite fascinating in that because distillers ferment at alarming high temperatures (alarming to brewers, that is) massive maturation compounds are formed that aren't always reduced, giving character to the distillate. However, maturation of things like diacetyl are indeed temperature sensitive, so although fermenting in the 90's F can give you unreal amounts of diacetyl, it is also reduced in a matter of hours rather than weeks, as is the case of traditional lager brewing where you're fermenting in the 40's and 30's.

It's been quite fun and interesting for me going from one style of fermentation to the other. Ale Yeast strains that I've used to ferment beers in the 60's F behave completely differently in the 70's F when I'm fermenting for spirits.

[Bourbon Boiler]

Thanks to all of you, particularly the insiders for expanding this whiskey nerd's knowledge.