Corn mash

[kmmuellr]

I'm an experienced all-grain homebrewer since 1996, but just put up my first cereal mash what will become a bourbon wash by the end of the day!

14.7Lbs of corn meal, fine ground from an Amish store in Northern, lower Michigan and a half pound of milled, honey malt, plus 12 gal of boiling water. Right now a big batch of polenta sitting in a BOP (keggle). I've got 2-row and rye that I milled this morning to add once the corn has gelled and temp drops. Calculated diastatic power of 46.2 lintner. Fingers crossed!

Its sitting in the basement at >185F w/ a heating pad under it, all wrapped in blankets for a few hours.

I'll ferment on-grain in the keggle, hoping for no overflow. Judging by how full it is right now, I'll probably chicken out and put 3 gal or so into a bucket once the yeast is mixed in. Does anyone have experience fermenting in a keggle, and how much head space is needed?

Corn 60%
Honey malt 2%
Rye 20%
2-row Malt 18%
Wheat 0%

Assuming everything works, I'll get another batch going tomorrow, so I can strip, strip, spirit in a keg CCVM (pot mode).

K

[kmmuellr]

45 min in, still over 185F. Plenty of water to keep things from being just a mass of concrete, but plenty sticky on the paint stirrer that I mixed with!

K

[8Ball]

Sounds like it should work and will make a good drop for you. I leave 20% headspace with my all grain ferments with good results. If you don’t have any high temp enzymes to add to your corn, you could add a couple pounds of the malt a little at a time while stirring it. Will help thin it out some even though the malt will be denatured quickly. Looking forward to hear how this turns out for you.

[Expat]

Process looks fine. Re stickiness, if you don't have any high temp enzymes handy you could sacrifice a small amount of malt to free things up.

I generally leave about 8" on my blue barrel, so a generous amount of head space for a keggle might be 6".


Sounds like you're planning for some honey bear bourbon, no?

Edit: lol ninja'd by 8ball

[Demy]

Make sure you have enough liquid mixture for a good fermentation. I would leave 1/4 - 1/5 of the volume empty (say 20-25%).

[kmmuellr]

Sounds like you're planning for some honey bear bourbon, no?

Slightly modified HBB, no wheat or oats, but yes that was an influence.

About 3hrs in and still at 180F. Thin gruel consistency, although the corn has definitely hydrated more. It seems more "plump" than when I started.

When can I be sure that the corn is fully gelatinized? Based on my reading, I'm assuming it has, but would like some confirmation or some way of knowing for sure before lowering the temp and throwing in the malt.

K

[still_stirrin]

When can I be sure that the corn is fully gelatinized?

Take a little bit on a spoon and put it into your mouth. If it's mushy and soft, like a pudding, then it is gelatinized. If it is still "crunchy" like the corn kernel (I know, you used corn meal so your's is probably quite mushy already), then it needs more gel time. The gelatinization process is the corn's endosperm hydrated and softened to start the long chain carbohydrate reduction. The texture is "creamy" when ready. It quite possibly won't be sweet yet, although the corn flavor is very inviting, like a cornbread dough.

If you hold temperatures, it should gelatinize quickly, especially if you have plenty of water. It'll become a "pudding" in your mash tun. The high temperature enzymes helps thin this pastey consistency dramatically, so I highly recommend getting some.

But you may see that using cornmeal instead of whole corn milled to a meal condition, is softer and will gelatinize much quicker. You've just got to get the "hang" of it. Sorta' like looking at the mash liquor and knowing when the conversion is nearly done. A little experience will tell you.
ss

[Twisted Brick]

It also depends on how you grind your grains, as larger granules tend to suspend in the initial effluence and contribute to a larger cap. At 2lbs/gal my (hammer-milled) bourbon grain bill is 26lbs, which rises maybe 2" and leaves about 1.5" of head space. Only twice has the cap pushed my indented lid up enough to require some removal. (mighta had some oats in there).

It looks like your total grain bill is 24.5lbs, which should be fine for a 15gal keg. A 20-25% initial headspace will most likely result in under-utilized fermenter volume. Just keep increasing your total grainbill until you know your limit.

On a side-note, one of the biggest benefits of mashing in a keg (aside from not having to transfer your mash to another fermenter) is the ability to cool your converted mash quickly. A wort-chiller and a box fan (periodically misting the keg walls) can drop your mash 35-40F in about 20min or so.

As has been mentioned, enzymes can convert your mash efficiently, eliminating the need for an overnight rest and the dangers that come with doing so.
.

[Durhommer]

It also depends on how you grind your grains, as larger granules tend to suspend in the initial effluence and contribute to a larger cap. At 2lbs/gal my (hammer-milled) bourbon grain bill is 26lbs, which rises maybe 2" and leaves about 1.5" of head space. Only twice has the cap pushed my indented lid up enough to require some removal. (mighta had some oats in there).

It looks like your total grain bill is 24.5lbs, which should be fine for a 15gal keg. A 20-25% initial headspace will most likely result in under-utilized fermenter volume. Just keep increasing your total grainbill until you know your limit.

On a side-note, one of the biggest benefits of mashing in a keg (aside from not having to transfer your mash to another fermenter) is the ability to cool your converted mash quickly. A wort-chiller and a box fan (periodically misting the keg walls) can drop your mash 35-40F in about 20min or so.

As has been mentioned, enzymes can convert your mash efficiently, eliminating the need for an overnight rest and the dangers that come with doing so.
.
IMG_8922.JPG

Nice fermenter

[kmmuellr]

It looks like your total grain bill is 24.5lbs, which should be fine for a 15gal keg. A 20-25% initial headspace will most likely result in under-utilized fermenter volume. Just keep increasing your total grainbill until you know your limit.

On a side-note, one of the biggest benefits of mashing in a keg (aside from not having to transfer your mash to another fermenter) is the ability to cool your converted mash quickly. A wort-chiller and a box fan (periodically misting the keg walls) can drop your mash 35-40F in about 20min or so.

As has been mentioned, enzymes can convert your mash efficiently, eliminating the need for an overnight rest and the dangers that come with doing so.
.
IMG_8922.JPG

Awesome info, Twisted Brick. Thank you!!

4.5hrs into this w/ the corn meal and things are definitely moving in the right direction. The consistency is now thicker, the individual grains have swelled, and as SS said it is getting "creamy" and soft. More like pudding like than a thin gruel. It has swelled to take up nearly all of the liquid now, but still stirs easily.

I'm at 172F now, so will go a bit longer, and put in the add'l malt probably before my wife gets home around 4.

I'm feeling pretty confident about this! Over the next few days I'll be building a bucket, ass press to go along w/ my BIAB bag, and should be good to go for pressing out the fermented grain.

My brewery is a set and forget, PID controlled eBIAB. I've not had to monitor a mash in a long time!

K

[Twisted Brick]

Thanks. It is the only one I've ever used.

I forgot to mention the size scales perfectly to squeezing/clearing for a keg boiler charge which translates to a tidy 3hr strip session. (ha!) The only downside is one strip per ferment so now I have two.

[kmmuellr]

Enzymes are cool.

Thin, creamy polenta resting at 170 degrees. Took all the blankets and reflectix off, hit it w/ a box fan and paint stirrer to cool. At 155 I put in the malt and nearly instantly it turned to liquid. So cool!!

Boiling water and corn meal at about 8:50am. Put in the grain around 4:30pm. Pretty easy work so far.

Its back to being wrapped up and resting. 150 degrees start.

K

[kmmuellr]

Broke down and put my wort chiller in. 130 to 83 in a couple of minutes. Pitched DADY.

17 brix on my refractometer, so 1.070-ish.

K

[Twisted Brick]

Nice. What yeast?

[kmmuellr]

DADY. Bubbling slowly this morning at 80F.

I've measured out ingredients for my second batch, just need to mill. Tomorrow morning I'll boil the water and start again!
K

[kmmuellr]

Success! Second batch finished at 1.070 yesterday as well. Both are actively fermenting. Batch 1 is assisted a bit by a heating pad on low, batch 2 is insulated a bit better, but I think I'll need to get another heating pad. My basement is about 63 degrees F right now.

I'll be spending some time drilling holes in a bucket to get my ass press built before fermentation is finished.

K

[The Baker]

Much easier to drill holes in a plastic bucket.
With a spade bit.

Geoff

[kmmuellr]

Success!

I did my spirit run on Friday, 2/5; made cuts on 2/6 and diluted to 56%. Sunday 2/7 I put aside 1 quart white, and 2 quarts w/ 1 charred barrel stave. One of the oaked jars I did 5x heat/freeze cycles on Monday/Tuesday. Yesterday morning I cut these jars to 43% and last night had some friends over to compare the three. Crazy the difference between white and the two oaks.

Heat/freeze cycles really smoothed things out, and the naturally aged one had a smokiness that was crazy. I'll be putting sticks in a gallon jar, and filling for some long term aging to see what happens.

Monday and Tuesday I also ran the sugarhead that I made with the grain, so I've got over 7.5 gal at 35% low wines to spirit run next week when I get the time.

K