Grains-in ferment or wort fermentation

[PeteB]

Have there been any threads discussing the pros and cons of fermenting mash with grains-in, compared with lautering and fermenting the wort?

I have done a bit of a search on this forum, but a lot if non relevant info comes up. Maybe I don't know how to use this search button properly.

If it has not been discussed before I would like to hear comments and experiences.

[KBFreeRange]

If you are using unmalted grain running grain-in is pretty much a given. The key is grind size and agitation during cooking, fermentation and distillation. All of your vessels need to have mixers or agitators that make sure that the small grain particles (1/64th") do not sink to the bottom of the vessel. In the cases of cooking and distillation this could cause scorching. In the case of fermentation it could cause a big mess if the CO2 given off during fermentation gets trapped beneath the grain that would settle to the bottom of the fermenter. When a submerged CO2 bubble pops, there's a hell of a mess to clean up.

[cowdery]

Grain-in throughout is the traditional method for American whiskey production. Lautering is typically done for malt whiskey in Scotland and other places malt whiskey is made. I believe there are micro-distillers who lauter corn mash before distillation, however.

[PeteB]

Is there much of a difference in flavor profile?

I am making 100% rye using 80% grain and 20% malted rye.

Lautering is extremely slow so I am considering other options.

[cowdery]

When I ask distillers in Kentucky why they distill on the grain they say, "because we can." Yes, it's more sources of flavor, but mainly they do it because the column stills they use can handle it, so why go to the expense of lautering?

[delaware_phoenix]

Traditionally, American whiskey had always been distilled on the grain even before the advent of the column still.

[PeteB]

Also, is there any increase in alcohol yield with grains-in?

With lautering there is always some sugar thrown out with the spent mash. In theory I assume that with grains-in, all this would all be fermented then all extracted with distillation.

Does this happen in practice?

[poca]

Coming from a brewing background I was very skeptical of on grain ferments. We haven't had any issues and I do strongly believe it adds flavor. That being said I would try and get it into the still as soon as fermentation ends. I believe letting it sit for to long after ferm. had caused us off flavors in the past. Also if your lautering a RYE heavy mash use rice hulls and quite a lot of em. I've always felt some distillers don't mash and lauter efficiently. When I brewed we always used a thick dough in and then sparged at 168F slowly, for a good amount of time. We always got 90-95% efficiency. But with grain in we are getting 100% so....

[PeteB]

A few questions for Poca, or anyone.

Are you using 100% malted rye?

If unmalted grain, at what temperature do you add malt?

At what temperature do you dough in? (I assume dough in means initial water + grist mix)

[poca]

Yes douging in is the initial mixing of water and grain. We've used malted and pre-gelantized rye flakes. I like using the flakes myself bc they almost dissolve into the mash. I usually dough in at 145ish. I just cool the corn down to that temp and add the grains, and let it rest. We do it all in the kettle and then chill from there and into the fermenter.