Three Grain Sour Mash

[pope]

I got a third mash in this weekend, this time a 'double' batch (really the size I intend to mash at now that the yeast is probably propagated) - 30 lbs of grain in 15 lbs of water, with the same ratios as the original post. It was in the 90's, dry, and still most of the afternoon (in case anyone was wondering as I list off my temp's and approximate times).

First, I do agree with Jimbo that under-hydrating the corn on the first mash was likely the biggest problem, a longer temp hold and a finer crush on the corn have definitely helped. I got about 3-3.5 gallons of backset off a small stripping run to get things started, so this mash is using about 20% backset, per the advice of a few of you, I may just leave it at 20% as you've recommended 30-35% is too sour (I'll try and find my pH strips and do a measurement on the next round to make sure I'm in range).

As I understand it from the glutanization chart posted in the Mashing & Fermenting section, corn glutanization occurs from about 142-172F, so I poured my 22.5 lbs of cracked corn into 10 gallons boiling water, brought it up to about 190F, and then left it. I checked it several times for about 5-1/2 hours, it took that long to get below 160F, when I crashed the temperature with 2 gallons of cool water and mashed in the rest of the grains. Landed about 145-148F after mashing in.

Checked it this morning and the whole mash was still about 128F (8-9 hours after mashing in the malts), and nice and sweet. I finally brought it down with the remaining three gallons of water but it definitely had a lot of time to glutanize and then have enzymatic activity. Measured 15.6 brix on 30 lbs of grain and 15 gallons of water, that's 80% efficiency, for the amount of effort involved I'm pretty happy with that. I'm still optimistic that there will be additional conversion during the fermentation. Anyway I think this is the method I'll be sticking to, I'm sure it's not dissimilar from everyone else's.

As far as insulating, I just used a keggle and put a lid on it, then threw a folded up Mexican blanket over the top. Not much insulation but it kept flies out and did seem to keep some heat in. I wouldn't want to insulate any more or I'd have problems cooling it off.

I still have to measure the abv of the first distillate, which was a combination of the two mashes which averaged 50% efficiency, I should be able to estimate the beer's ABV by comparing it to the distillate ABV, right?

[der wo]

You see it gets better and better each time. Don't stop experimenting and note down the details each time.

I still have to measure the abv of the first distillate, which was a combination of the two mashes which averaged 50% efficiency, I should be able to estimate the beer's ABV by comparing it to the distillate ABV, right?

The most exact two ways to determine the abv of a mash is the OG-FG calculator or distilling:

(OG - FG) x 130 = %abv
for example:
(1.070 - 1.000) x 130 = 9.1%

Or you strip the mash down until the distillate contains no alcohol anymore. Then you can measure the abv of the low wines with your alcoholmeter and calculate the abv of the mash.
If you want to use the last very low alcohol fraction is another question. I use it always for whisky. But you could collect and measure it seperately and decide the next day after stripping.

[pope]

I've been getting some good readings on the last few batches, SG and FG are in line with limits/expectations, thanks for all the help!

One problem I see building is the viscosity of the mash. What I've been doing is letting the beer & grains sit in the fermentor (okay, trash can) for about 5 days, then I use a paint strainer and manually wring out as much beer as I can (and feed the chickens with the damp grain that remains, which I'm sure is giving them alcohol dependency issues). I leave some grain to host yeast for the next fermentation. Then I let everything rest for a few days and it settles well enough to use a colander and pump out the beer I need for stripping.

So what I see is this: a middle layer (between still-worthy beer and grain) that is thick ans syrupy, made up of the flours and fine grain particles that accumulate from milling. It seems to accumulate and grow in size with every fermentation (which makes sense as I'm not removing it by straining or distilling). I typically run electric and am sure this would scorch and probably ruin the element, I could run gas but wonder if this would scorch as well. Should I rack to a carboy and use sparkolloid or bentonite to compact the lees? There's definitely too much alcohol in that portion to let it go, but I'm not sure of the best approach.

[der wo]

A few here use clearing agents like bentonite or gelatine for neutral washes. I never heard of using them with whiskey. Probably it removes some taste. But who knows, try it, perhaps you like the cleaner taste even more.
Scorching is one of the crucial points with grain. Yes, the fine milled stuff is most dangerous. The easiest trick against scorching is to insulate your boiler well, that you can distill at the same speed with less energy. It helps A LOT.

[pope]

Two questions about scorching: 1) is it pretty easy to smell/taste in the stripping run? 2) how do you clean a keg that's got burnt grain on the bottom? PBW and a long soak?

Of course I'm not trying to scorch anything but just thinking about worst case scenarios.

[jedneck]

you will not be able to miss scorch. its the foulest nasty sh^& that i've ever seen come outta a still

[jedneck]

https://youtu.be/w8M9A0lI7JU" onclick="window.open(this.href);return false;" rel="nofollow
the infamous randymarsh scorch. if ya see this chances are good it's trash

[pope]

Glad I've never seen that before! Thanks for the video.

[jedneck]

be even glader that ya never tasted it

[der wo]

This video is extreme.
A clear but a bit yellow distillate and a bit smoke coming out of the condenser is a normal scorch. The smoke is cold and smells different than you probably expect.
Cleaning: Soaking the bottom with hot water and washing soda over night will help to clean it with a scrubbie.

[pope]

Well my biggest fear of scorching my kettle is the 2" opening I have to get at the bottom if it collects burnt grain solids.

Anyway, it turns out I scorched what I thought was a very clean portion of wash tonight. I was running electric, and the moment I caught the smoke (about 122F, before any distillate came out), I shut it down, removed the element, gave the keg a shake, and put it on a burner, and it's run clear since. The distillate tastes pretty much like all the other low wines so far, though I may still give it a small spirit run just to be safe.

But, as my concern for scorching was heightened, I decided I'd explore the potential on a much thicker portion by ladling a bit of the thin-soup consistency stuff into a saucepan and simmering it in the kitchen. No scorching, and I was suddenly reminded of reducing sauces and simmering thick things for years in the kitchen. So, I'll give the thick portion a go on a simmer as a stripping run, and keep my fingers crossed.

But, this thick portion is bound to have some yeast in it, so my question is this, what are the feelings on distilling yeast? I know many are against it, but I also know that many commercial distilleries produce fine spirits and simply pump the wash, grain and all, into the still, and strip the alcohol out of everything before sending the slop off to a ranch or dairy for cattle.

[der wo]

When you ferment on the grain, all the yeast will be in the still. So you don't have to make a decision. But when you ferment off the grain, you could siphon it off. But I never heard, that the Scots do that. You have to decide. I don't think it is crucial, both ways can result in great whisky, probably a bit different, so try out what you like.

[pope]

That's good to know. I've always cleared birdwatchers, hook rum, etc., and do plan on doing the same for single malt, but somehow I never picked up that there wasn't an effort to separate yeast with on-the-grain ferments. I've always strained the grains and then watched with frustration as it cleared to a slightly cloudy gold wash in the top third, and layers of increasingly thick flour muck in the bottom two thirds.

I ran pasta-sauce consistency wash this morning (nice and slow) with no scorching, which was very exciting for me. I used to let this portion go in all-grain batches. Thanks for all the help!

I'm about 180 lbs of grain into this (planning to go another 120, more if the yield isn't enough to fill the barrel). The flavors and smells keep getting more complex. I do have a growing colony of lactobacillus film that forms on the surface of the washes, but as long as I work quick I'm not sure I should be too worried about it, I know some lacto fermentation can be a good thing.

[pope]

Alright, I'm nearing the end of my long, 325-pounds-of-grain journey, broken into 13 cooking sessions. I have 15 lbs of grain left to cook (tomorrow night and the following morning), and while I've still never measured my yield precisely, I have been running stripping runs to 98.5C and will measure total low wines against the total amount of grain to get an idea of the average efficiency. Per batch, I was cooking 30 lbs of grain in 12 gallons of water then rinsing the vessel with an extra 3 gallons to get to the 2-to-1 ratio. I finally knocked down the recipe 20% so that I could cook 24 lbs in 12 gallons, and the work and the yield have been much better.

Not much has changed in the overall process, but I boil water, add corn and kill the heat, wrap well, when it gets down to 140's (about 12+ hours later) I mash in the malts, rest 10 min, step up to 148, rest 15 min, step up to 154, wrap and walk away until I can toss it in the fermentor (another 12-24 hours later). I scoop a few gallons of loosely wrung-out grain in, give it a stir, and fermentation fires off nice and quick.

My brewhouse efficiency is capping at about 16 brix/1.066 SG, that's with 75/15/10 corn/6-row/rye. Per online brewing calculators like the one at brewersfriend.com, that is 85% which I'm understanding to be close to the maximum, please correct me if I'm wrong. The wrung out grain doesn't look like it's got much left to it once fermentation is complete, it just looks like a bunch of corn kernel skins.

My low wines are averaging about 35% abv last time I checked, I'll post a detailed tally in another week or so. I'll have to split the spirit run into at least two batches, probably three. I may do three and then a final all-feints run.

Any thoughts from experience on using/not using backset in the spirit run? I've never done it but have heard of it being done to add flavor.

[pope]

Also, I wanted to add that, at 1.066 SG/16 brix, when fermented dry that wash is theoretically coming out to around 9%.

[shadylane]

Also, I wanted to add that, at 1.066 SG/16 brix, when fermented dry that wash is theoretically coming out to around 9%.

Glad your having a good time learning
Using a hydrometer, What's been the final gravity when fermented dry

[der wo]

I don't use those calcs, because I normally ferment on the grain with fine milled grains. So my SG is good always. And when I am mashing malt whisky off the grain, I also get much, because I use two waters, what helps, and I have an agitator working for me. Perhaps a better malt mill would optimize it further.
But I always hope for a low FG, so as shadylane writes, a FG measurement would be a good idea.

Instead of diluting the low wines with backset I would strip longer. To stop at 98.5°C is much too early IMO. Per 10l mash I would collect 3.5l low wines. The temp will be around 100°C.
BTW you will be able to calculate the exact abv of your mash when you collect all the alcohol. Measure the abv and volume of the low wines and you can calculate it more reliable than with the OG-FG-calculator.

[pope]

Okay so I was way off in my estimation, my best extraction mashes (16.2-16.5 brix) finished out at 1.020 FG. That would put me right up against 6.0% abv. But ultimately as pointed out above, the total volume of low wines x the low wine abv compared to the total pounds of grain will be my best estimation of efficiency. I also may be getting off on my FG reading because I am getting some lactobacillus activity.

I'll start stripping to a higher temp/lower abv, I'll go past 99C from now on. I'll check in with my total low wines and abv's when I have them gathered. Thanks for keeping up on the mashing with me guys! I think I'll be making a little bit of birdwatcher's after all this work.

[pope]

Okay one more question - I strained off some mash and got it into the still but didn't have the time to run it, so I heated up enough to keep anything from growing, then the next morning fired it up. It must have been enough time for solids to collect on the bottom because even though I gave the keg a few shakes, I still got a lot of really bad scorching. As soon as I saw smoke (80C), I shut it down, and after a few hours I poured out the mash - I'll strain this and run it, whether or not it's ruined remains to be seen.

BUT, how do I clean the damn keg? I have the standard 2" opening at the top, and a welded on 1.5" on the side where the element goes for electric runs (it's been capped off mostly for all the gas firings I've done for these thicker mashes). I'm soaking some concentrated PBW solution on it overnight, I'll take a brush to it as best I can, but I'm contemplating buying the parts to weld on a 4" 'manway' for my arm so that I can get in there with a stainless scrubbie. I can try tacking some stainless scrubbie to a stick, but I don't think I'll have enough maneuverability going through a 1.5" opening.

Any tips for removing the scorched sludge off the bottom are very welcome.

[der wo]

Sorry for your loss. I had a lost batch too yesterday...

Soaking it in boiling water with soda will help a bit.

[der wo]

Scorching is most likely while heating up, because the mash does not yet move around. Next time you could stir the mash while heating up with a wooden mash paddle up to 60°C or perhaps a bit higher, then reduce the heat and close the still.

[pope]

Sorry for your loss as well!

Right now I can't fit any tools in the keg because of the small openings, but after a little thought I've decided to use a concentrated sodium hydroxide/lye/NaOH solution as that eats pretty much everything (except stainless and plastics, perfect for me). I have a LOT of experience with lye but I'll say this here in case anyone ever searches the forums and takes this advise: USE EXTREME CAUTION when handling lye. Never add water to lye crystals, only add crystals to cold water. ALWAYS use eye protection and do not breathe fumes. Some of this may seem like common sense, but since we're all in the midst of a DIY hobby, I know that among industrious and competent individuals, attitudes can get cavalier sometimes. I would consider using this extreme of a caustic only as a last resort, but given my situation I really have no way of even reaching the blackened scum, let alone with the force to manually remove it.

At any rate, I'll be trying it tonight and will report back soon, but hopefully this will save me a lot of time, elbow grease, and money. I'll also be running the briefly scorched batch and we'll see how that tastes.