Full Mash Contradicting Info

[OzKev]

I've almost finished molasses washes, so about to embark on a full mash. I'm looking at 5kg corn, 500g distillers malt and 750g Malted Rye as my first batch.

I've read 2 bits of contradicting info and want to clarify before I try.
Corn gelatinization temperature.
In beer brewing we use 62c to 77c range.
But I've read to keep it >85c for 1 to 2hrs when making a full mash spirit wash.

Fermenting on the grain
I've read to ferment on the grain, and also not too. What are people doing. I assume fermenting on the grain will allow most husk astringency to come through creating more flavor. Is this what we want? If not, I'd prefer to leave the grain out of the way.

[tipsy]

I've only done 1 what I'd call a full bourbon mash.

I boiled my corn until soft then let cool before adding my barley to try to get conversion at 65c

The corn is like porridge until it converts and becomes thinner. I think it would be near impossible to sparge that is why I fermented on the grain.

I'm currently looking for an easier way :pray:. My efficiency was shithouse.

[Kimbo]

Further to what tipsy said,
corn is really hard to get full conversion, if you mash it in the 62-77 deg range you wont get enough gelatinisation happening.
You will convert whatever starches have gelatinised, but not the starches that havent.
thats why people tend to cook the corn hotter for a while-- to try and get better conversion.
as for fermenting on the grain, if you get a full conversion there will be absolutely no flavour left in the grain. In fact, the grain would just be taking up valuable fermenter space.
I hope this helps mate :handgestures-thumbupleft:

[OzKev]

I mashed it in just after my initial post, at 11am. It's now 3pm. From 11 until just after 12 it was at 90c, and then I upped the controller to 96c. It's doubled in volume and become milky, but there are still a lot of hard kernels left. I may bump the element on 100% cycle for a while to see what happens.

[tipsy]

What sort of system are you mashing with?

In 'Making pure corn whiskey' he recommends adding some malted barley to the corn around 63-65 first to get the corn mash thinner before boiling.
Then add the rest of the barley once it's back down to 63-65 for the rest of the conversion.

[OzKev]

I'm mashing in my small brewery as a pilot to test it before attempting a full run on my big system. The small brewery is a 1V setup. A 50L pot with a 19L pot inner pot to hold the grain. The inner pot has a false bottom setup in the base to allow the wort to drain. There's an electric element in the bottom of the 50L pot, and the 19L is on legs to sit just above the element. A pump draws wort from the base of the 50L and recirculates half back past the element to stop it burning the wort, and the other half back in the top of the 19L pot.

Not the best pic but it give you an idea.



I gave it 30mins on the boil and have turned off the element. I'm letting it cool naturally to 63c and will add the malted barley and rye. Next time I'll try and do a mash first, then boil, then do a second mash to see if it helps. Looks like it will be a while before I finish today.

[OzKev]

I should add that pic is not from today.

[OzKev]

I've really got to do this differently. Added corn at 11am, it's now 6pm and the iodine test still shows incomplete conversion. I'll leave it for another hour and test again. :crying-blue: On a positive note although there is some hard bits of corn left in there, most of it has been converted into sugar as the grain now takes up a lot less of the initial volume. The wash looks very milky. Although I have incomplete conversion at the moment, the current refrac shows 65.4% efficiency. To give you an idea, normally I get 85% but don't have a benchmark for this style of brewing. I'll check it again in an hour or so.

Plans for next time.
Get a big pot and go back to a gas burner (I have a couple of 150,000btu burners in the parts cupboard). Boil the crap out of the corn for an hour and check it. Then use an immersion chiller to drop the temperature to ~63c fast. This should save a lot of time on the day. :clap:

[res]

I have done many AG corn based runs, mostly small scale, 10-15lt or so and found 2 hours at 85+ temps more than enough time to breakdown the starch in corn. I assume you cracked it or started with cracked corn? In my experience the yellow husk never really gets very soft, instead all the white starch inside dissolves into the water leaving you with a gloppy soup with packs of husk flouting around. After it cools to 63 I add the malt and wrap it up for the night. Never failed an iodine test yet, and between the barley, wheat and corn husks sparging is no problem.
Hope that helps a little. :handgestures-thumbupleft:

[res]

You may also want to look at the diastatic power of you malt :think: When I do a corn mash it's closer to 2/3 corn- 1/3 malt

[bt1]

yep well boil corn for a couple of hours, then immersion chiller back to mashing temp.

The crack looks fairly course, I've found finer is better but need stirring to avoid burn.
Mash at beta then alpha long rests...but yield is avg at best ...
AG is expensive and time consuming.

A partial then topped up with sugar for mine. Got the flavour, turn around time and yield.

As for malt Barrett Burston/Joe White Galaxy got plenty of grunt for conversion but still add some caramalt for flavour as well works for me.

enjoy!
bt1

[OzKev]

The Distiller malt I used was BB Galaxy, along with the malted Rye it gets me easily over the magic DP>30. The corn was chook feed, cracked corn. Next time I may throw it through my mill as I was reading about it speeds up the gel'ing time.

I think the main thing I was looking for was all husks/shells to become soft. But I'm guessing that is not needed. I just checked the brix, and BeerSmith says I've got 81.1% eff. So I cannot complain about that. :dance:

It's pretty well insulated, but I'm going to throw extra insulation on it and leave it for the night. I don't expect much more gravity points although there still is a few black flecks in the iodine test.

I've just got to make it quicker now.

Thanks for all the help and ideas so far. :handgestures-thumbupleft:

[bayshine]

I've done about twenty corn mashes now and am getting better each time
I do mine along mountain moonshiners recipe but in an insulated cooler
I crack the corn a lot finer with my mill and dump 95 degree water on the corn
And bash the piss out of it with a plaster mixer and drill
It then gets very thick and then I throw in rye and wheat meal,
Beat that with the drill(you'll need 240v) this will set like concrete.
I then stir with wooden broom handle and then leave sit till it gets to 72 deg.
I then add Alfa enzyme from the hbs(or sacrifice some malt) and this thins it instantly.
I stir occasionly until it gets down to 65deg and then add the malt.
Now I can use the the drill again and mix every 15min for an hour or two.
I let it sit in the insulated cooler over night and then throw into the fermenter in the morn
And top up with water. The best sg so far has been 1.075 with the worst at 1.050
It takes all day but only needs to be monitored for the correct temps/timing
So can do other things like running the still during the mash
I've found it to be a fair bit of work but worth every bit of it.
I've scaled up so that I get 100lt of wash on top of the grain bed and split that
Leftover grain bed into the next two gens

[OzKev]

I noticed the airlock on the fermenter of the corn wash has been getting slower, so today I took the lid of the fermenter for a sniff and measurement. It stinks like someone has filled my fermenter with vomit :puke-huge:

Is this normal or has some funky bacteria overtaken it?

[bayshine]

Thats how my last on smelt with vinager infection

[OzKev]

Last night I took the lid of for a final check. No film or any visual signs of an infection. Still stinks really bad, I'm talking stuff that make you want to throw up. I poured some in a glass and let SWMBO have a sniff, ok that was not a good idea 8-} I dabbed my finger in and managed to have a taste test, Lactic Acid. So it looks like one of the Lactobacillus bacterias have taken a hold. My guess is from me leaving it over night to cool, and it still being 45c the next morning, has presented a perfect place for the bacteria to jump in and party. My first corn mash is to go down the drain. :crying-blue:

[bayshine]

isn't a lacto infection what the big guys chase in bourbon?
after watching the makers mark distillery they taste the fermenting wash and and comment on it being sweet yet sour
any way bad luck mate :handgestures-thumbdown:
I've been crash cooling my washes with ice in this hot wheather of late so i can get my yeasties in as fast as i can
don't know how i could boil the wort after mashing with my set up,but its on my mind after my last infection :think:

[Brendan]

They do use lactobacillus bacteria to some extent, but the final mash should not smell unbearable at all.

When you use Pint's method of a corn sour starter, there are 3 bacteria that you allow to work, which is also referred to as lacto-souring. The first bacteria gives a creamed corn smell, the second bacteria smells like vomit (seriously), and then the 3rd kills that one and finishes it off with a nice sweet corn smell...its this bacteria that is introduced to the mash.

If your mash smells similar to vomit, as you said it was unbearable, I'd say you had that second bacteria take hold...this would be a pH problem, as the right pH encourages the 3rd bacteria to take over and it finishes off very acidic (just like backset, which is what the sour corn starter is replicating), inhibiting the unwanted bacteria...

[Kimbo]

They do use lactobacillus bacteria to some extent, but the final mash should not smell unbearable at all.

When you use Pint's method of a corn sour starter, there are 3 bacteria that you allow to work, which is also referred to as lacto-souring. The first bacteria gives a creamed corn smell, the second bacteria smells like vomit (seriously), and then the 3rd kills that one and finishes it off with a nice sweet corn smell...its this bacteria that is introduced to the mash.

If your mash smells similar to vomit, as you said it was unbearable, I'd say you had that second bacteria take hold...this would be a pH problem, as the right pH encourages the 3rd bacteria to take over and it finishes off very acidic (just like backset, which is what the sour corn starter is replicating), inhibiting the unwanted bacteria...

:text-+1:
I've done a few Sour corn starters and had some really good results :handgestures-thumbupleft: Others opinions may vary

[Brendan]

Yeah same Kimbo...so you know that vomit smell that appears in the middle, but is soon taken over by the finishing bacteria then? I'm assuming he's ended up with that holding its ground in the mash, and the pH hasn't gone low enough (ie. hasn't soured enough).