Scratch That Itch - Off the Grain

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bilgriss
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Scratch That Itch - Off the Grain

Post by bilgriss »

I've seen several questions recently asking for clarification for the differences between fermenting on and off grain. What are the advantages or disadvantages of either, and why do we make the choices we do. Personally, I do and have done both, depending on my agenda. Coincidentally, when I was first looking for an all grain recipe using Scratch Grains, I found several UJSSM-type procedures, but nothing quite what I was looking for. I have developed the following, and generally do this one off the grain. I thought I'd put the recipe out there, and also explain some reasons for either fermenting on or off the grains at the same time.

Scratch that Itch. (sparged, off the grain version)

Ingredients
12 lbs Scratch Grains ( From Tractor Supply. 1/3 each of cracked corn, wheat, and barley)
4 lbs malted barley
3 cups rice hulls (optional)
1 gallon backset
1 Tblsp gypsum
7.5 gallons water
liquid enzymes

Simple Procedure
Evening: Heat 4 gallons of the water and the backset to boiling. While it's heating, I crush the 12 pounds of scratch grains with my roller mill, once at about .060" gap, and a second time at about .030". This really crushes the grains, leaving corn, wheat and barley hearts nearly powder-like, but leaving all the hulls intact. This works for me much better than my Corona mill, which tends to do equal damage to husk and starches alike. If fermenting ON the grain, that's not a big deal, but intact hulls are really useful for sparging if you want to remove wort from the grain bed.

When the water begins to boil, I add it to my mash tun, a Rubbermaid cooler with braided hose for lautering. Add grains and gypsum. Stir. When the temperature drops to 180F, add the high-temp enzymes, about a teaspoon. Stir more. The corn will have already begun clumping together, and a short stir puts the enzymes to work, resulting in a loose mixture. Put on the lid, cover with a blanket, and let it rest overnight.

Morning: Depending upon how cold your mash area is, the temperature will have stabilized between 140-150F. Grain will have also settled somewhat, so if the temperature needs to be raised, just skim some of the liquid from the top, and put it on the stove. A gallon heated to near boiling will bring the temperature up around 8 degrees, give or take. I target 150F, at which point I stir in the 4 pounds of malt, rice hulls, and 1 tsp of the gluco-amylase enzyme. Stir it all in, and the temperature will stabilize 145-148F. Cover your mash tun again and let it rest. I've found that patience increases yield, so let it go.

Evening: Or afternoon, or whenever you are too impatient to wait any longer. I like to give it at least 4 hours. The largest part of enzymatic activity happens in the first hour or two, but you keep gaining sugars for a quite a while longer, even after an initial iodine test shows completion. I think there's continuing activity with the larger pieces of grain slowly coming into suspension. Again, if you ferment ON the grain, this isn't a problem, as enzymes keep acting during fermentation. But for this exercise we're separating grain from our liquids and want to get a decent yield.

Sparging: Drain the mash tun into a big pot. Let it go a while; after the first 80%, it will slow to a stream and then drizzle. This first running will be around 1.080 specific gravity, and you want to capture most of it, so let it go until the drizzle starts to turn into a drip. Good enough. I then close the valve, and pour the other 3.5 gallons of water into the mash tun. Stir it up really well, and give it about five minutes to settle. Then drain the liquid again. The second running will be more in the 1.020-1.025 range. Let it go until you are done. Waiting for drips is less important with this lower gravity running, and you'll end up with close to 6 gallons at about 1.060 specific gravity.

Note that both times you start draining the mash/lauter tun, you should catch the first quart or half gallon in a separate vessel. It will be very cloudy/grainy. When the liquid begins to clear, pour the cloudy mixture back onto the grain and let the whole balance drain off into the big pot. This eliminates the vast majority of the trub which otherwise occupies your fermentation vessel. Also, with regards to sparge temperature for the 3.5 gallons - I just use cold tap water. You'll gain a little efficiency if you use hot water, which helps extract a bit more sugar from the grain, but it's fairly minor, and the lower temperature sparge helps bring the temperature of the total liquid down pretty close to yeast pitching temperatures.

Pour the six gallons into your fermenter. I use a glass 6.5 gallon carboy (got a few...) and I like to pour through a funnel for aeration. Works really well. When it's cool enough, pitch yeast. In the summer, I like a neutral ale or bakers yeast. In the cold months, I use Red Star Premier Cuvee, which likes the cold temperatures, and finishes clean also. I wouldn't use it in warmer weather though. This time of year, fermenting arount 60F, it will tear through this particular ferment in about three days, and be largely clear for a stripping run in 4-5 more.

Result
This is an American whiskey, from mostly raw grains. It can't be called a bourbon, but it definitely is bourbon-like. The added malt gives it some richness and mouthfeel. It makes a very fine drink, which ends up being only a little more pricey on the grain that an all corn mash. Currently a 50lb bag of scratch grains at Tractor Supply is about $11, only a couple more than cracked corn. 50 pounds is almost perfect for exactly four ferments, and the final yield for each between 5.5 and 6 gallons is ideal for my 8 gallon boiler, to do four stripping runs.... which yield almost a perfect boiler-full of low wines between 30-40% for a good spirit run. Follow your favorite aging protocol, and enjoy.

Theoretically, you don't need added enzymes for this recipe. However, in addition to increasing the yield somewhat, the hi-temp enzyme makes it far easier to get a good filter bed for sparging and fermenting off the grain. Things just don't stick. It's awesome. The rice hulls are optional as well, but I know that adding them means I can drain sparge water wide open and never worry about a stuck sparge. The whole process is predictable and easy, and doesn't take any special care. If you skip the enzymes, grind rather than crush grains, and get a little hasty, I suspect it would be easy for the corn to gum things up and make batch sparging more difficult.

Don't skip the backset, as it sets your pH well for the second dose of enzymes. If you do skip it (don't) then substitute a gallon of water and adjust the pH using your favorite alternate method, as needed. The gluco-amylase works effectively with pH levels below where your mash may otherwise end up

On the Grain versus Off:
In many ways, this is a potato / potato argument (pronunciation important in this written phrase). Many will aggressively tell you why you should do one or the other. Fine. I do both, depending upon recipe or inclination. Doing an all corn mash, it's going to take a lot of energy to effectively separate the two. A bourbon mash is still going to be a lot of effort. But provided enough grain with enough husks to create a good filter bed, I like the ease of post fermentation steps off the grain.

ON the grain:
Advantages:
Easier to mash in the fermentation vessel.
"All at once" dumping of ingredients and one shot mash.
Continued enzyme exposure throughout fermentation results in more fermentables and higher yield.
Some report more flavor.
Disadvantages:
Requires separation of grain post fermentation.
More difficult to get a clear product for distillation.
Some report tannin extraction, harsh flavors.

OFF the grain
Advantages:
Ferment clears faster.
More of the fermented product ends in the still.
Some report smoother flavors
Disadvantages:
More initial work during mash
removal from grains may reduce total fermentables.
My dog is more likely to feast on sweet grain than fermented grain while passing the compost pile.

I personally haven't experienced tannins or off flavors from fermenting on the grain. I have, however, fought to extract beer from grain. Spill it in your kitchen and it smells like a frat house for some time. I tend to separate, pressing in nylon bags, and then let it rest a while anyway in carboys so that I can get a cleared product in the fermenter. The amount of trub that settles in the carboy might be four to six inches high after pressing the grains. If I used a thumper, I could use some of it, but I generally flush most of the sludge. By sparging and fermenting off the grain, I can limit the trub layer to about 1/2", and when it's done, everything in the fermentation vessel goes into the still. So while in one sense I have a reduced yield, in another I do not.

In summary, I don't feel one method is obviously superior to the other. Sometimes I just like to ferment on or off the grain, because.... I do. Your protocol, equipment and disposition may lead you in a clear direction.

And if you should care to try the recipe, let me know how it turns out.
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Re: Scratch That Itch - Off the Grain

Post by BlackStrap »

Nice post... I like the explanations, Gives me incite for what to do when shooting for something particular...Thank You :esmile:
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Re: Scratch That Itch - Off the Grain

Post by StillerBoy »

Thanks bilgriss for the good write-up.. nice to have the point on the same page..

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bitter
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Re: Scratch That Itch - Off the Grain

Post by bitter »

Nice write up..

I think each has its place. I did a 100% barley on the weekend and used my mash tun to filter the wort off the grains. Got 84% efficiency so did pretty well. I like this method as its a bit cleaners and squeezing grain.. is one thing I dislike. The other benfit here is doing a boil till just past hot break and the wort is less likely to puke when run as will not foam as bad. Also if you want to leave things for a long time, if you ferment with airlock this is less likely to get infected

I do also do on the grain ferments but mostly when something just not spargable.. and when using enzymes to get more outa them.. But is more likely to get infected.. but might be a good thing... or bad depending on your intentions.

Both are good and have there place.

B
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Re: Scratch That Itch - Off the Grain

Post by bilgriss »

Bitter you echo my thoughts exactly.

Generally, the more corn I use, the more likely I am to ferment 'on' the grain. An all malted barley mash is most likely going to get lautered.
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Re: Scratch That Itch - Off the Grain

Post by bilgriss »

I thought I'd add a few notes after making cuts on the latest spirit run, while my recollection is fresh.

Enzymes, yeast and Temperature: There is enough malt in this recipe (25%) that enzymes are theoretically unnecessary. What I have noticed, however, is that following the described protocol using liquid enzymes, I get a more consistent gravity reading, and wider hearts cut than without. I'm not completely certain as to why. I was second-guessing my notes after going through all the jars, because I had noted more keepers than I thought I should. But going back through the outlying jars, I agreed with my notes. Since I'm intending to age this one for a good while anyway, I went with it. Another factor I've found widens the hearts cut is a good, neutral yeast pitched at an adequate rate, fermented toward the lower end of its temperature range. Understand that's not an absolute observation and I don't want to start a yeast-off argument - It's just something I've noticed myself. Your mileage may vary.

Flavor:
Not enough corn to be a bourbon, but shares most of the general characteristics. Nice sweetness comes through, especially from late heads into hearts. Really good aging stock with lots of grain flavor that comes through from the scratch grains, mellowed by the malt. I'll keep coming back to it, but I tweak parameters when I run across things I want to try.

I noticed again how clean the low wines look compared to something similar I would ferment on the grain. The extra settling in the carboy helps reduce the puking potential, I think. I usually miss my queue at least on one of the stripping runs and end up with some cloudy looking stuff. Not sure that's important, but it's noticeable.

In any case, one more down, infinity to go.
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Re: Scratch That Itch - Off the Grain

Post by Shine0n »

Nice write up and explication of the process, I do have a question though... the rice hulls, how well do they work when using cornmeal? I haven't tried them as of yet but from straining my last mash (pita) I hoping to find a easier solution for this.
I ferment on the grain and the sediment on the bottom is far worse than the more grainy stuff on top, plus I strain enough of the clear wort to fill my boiler and use the grains in the thumper to steam.

I squeeze the grains in order to get 2 runs worth of clear wort and then use water with the grains in the thumper or feints if available.

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Re: Scratch That Itch - Off the Grain

Post by Single Malt Yinzer »

bilgriss wrote: ON the grain:
Some report tannin extraction, harsh flavors.

I personally haven't experienced tannins or off flavors from fermenting on the grain.
It's an issue for beer, not for distilling. Tannins don't come over to the distillate. It's also why distillers can squeeze the grains to get the last bit of wort out of them. For beer that also will encourage tannin extraction. One of the nuances between the two.
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Re: Scratch That Itch - Off the Grain

Post by bilgriss »

ShineOn, Rice Hulls: it would depend upon the amount of cornmeal and what else you are mashing along side it. I haven't tried lautering a majority of cornmeal well ground corn meal. Crushing with my roller mill in two passes creates a lot of powder/meal, but there's still a fair bit of small chunks mixed in.

I've had good luck with mashes that would otherwise tend to get stuck, including rye without a beta-glucan rest. It's amazing how much a small amount of rice hulls help. But I haven't pushed that boundary to the limit, by any means.

Someone has reported lautering with cornmeal. Maybe Still-Stirring? Perhaps they'll chime in......
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