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Hey guys,
As I have been making bourbon batches with cornmeal for the last few years I have been cooking the corn for shorter lengths of time. My current process is draining boiling water into my fermenter while pouring in cornmeal. Stirring with a paint mixer, the corn is cooked and unworkable within a couple minutes. I add Sebstar HTL and it loosens up to stirable then I let it sit with occasional stir for an hour. When I started I would go 90-120 minutes but found an hour yields same result. Now I am wondering, is there any point in letting it sit for an hour? Anybody do it for less- like half hour? It would speed up my process as I make two batches on the same day due to boiler size.
Thanks!

This would depend on what the rest of your process is and what you use.

I use Yellow label yeast and don’t cook at all.

If you are using enzymes and getting complete conversion it is working. If you still have unconverted starch you have a problem.

I have done enzymes and distillers yeast and had very good results.

Tell us some more about your process.

Rest of process is pretty straightforward... mashing with Barley and Rye for enzymes, using Safale US-05 yeast, fermenting at 68f.
Getting very good conversion/yields now- on my 35th batch!
My question was more on what is actually happening when cooking the corn with HTL. I realize it is beginning to convert the starches to fructose which is then broken down further by added grain enzymes. I am wondering how long this process actually takes- a full hour or considerably less? I know the best option is to experiment but I was curious if someone else has already investigated? Haven't been able to find anything searching here and online.
Thanks.

The importance of cooking is not about conversion. It's about gelatinizing the corn and making starches available FOR conversion.
The length of time is indeed related to the rest of your process, and the grind of the corn. Meal takes less time to fully gelatinize than cracked, due to more surface area relative to the corn itself. I've never timed a minimum, but if you wanted to do a series of cook times and document your process and at what time efficiency suffers, we'd love to read about it.

The cook/gelatinisation time is directly related to how fine the grind is and the temp you use. If you use course flour or meal size and say 250 for your corn, the starches will gelatinize in about 5-10 mins. If its coarser grind and your temp is 190, it is going to take 45-60 mins.

The time to convert the starch to sugar is based on what enzymes your using and how much you're using.

It's theoretically possible to mash corn flour at 250f (high pressure steam) and hit it with enzymes in a continous flow that the whole thing happens in just a few minutes... this is what they do in cereal plants. This just isn't really economical on the hobby scale.

You could steam mash at 212 cut the gelatinisation time down to about 30 mins, and once in the right temp zone use elevated amount of enzymes with agitation to get your conversion in a shorter time.

StuNY wrote: ↑Mon Jan 15, 2024 4:29 am
My question was more on what is actually happening when cooking the corn with HTL. I realize it is beginning to convert the starches to fructose which is then broken down further by added grain enzymes. I am wondering how long this process actually takes- a full hour or considerably less? I know the best option is to experiment but I was curious if someone else has already investigated? Haven't been able to find anything searching here and online.
Thanks.

Over dozens of 13gal bourbon mashes I've tried different strike temps (settled on 200-205F) but with cornmeal, haven't found a way to shorten gel time. I have never 'cooked' cornmeal, only mashed in and let it rest, insulated, about 190F. I let it rest 90min or so. I have plans for a corn steam mash test at some point but not holding my breath for spectacular improvement. I do like bolverk's idea of a pressure cook though.

This is the best paper I have found on how corn granules gel. My main takeaway was to physically observe the cornmeal granules grow fuzzy and subsequently blow apart to tell how gelatinization has progressed. Luckily, enzymes continue do their work (if not boiled) during the ferment, albeit a lot slower.

Thanks for the link to the paper Twisted Brick- lots of good information in there! I find the fine cornmeal gels pretty quickly with boiling water dumped into insulated fermenter. Based on what I read in the paper I am going to try 1/2 hour of "cooking" before adding the rest of the grains. Seems that just getting the grains to swell is all that is needed at that point and then the HTL does some quick converting.

StuNY wrote: ↑Mon Jan 15, 2024 4:52 pm Thanks for the link to the paper Twisted Brick- lots of good information in there! I find the fine cornmeal gels pretty quickly with boiling water dumped into insulated fermenter. Based on what I read in the paper I am going to try 1/2 hour of "cooking" before adding the rest of the grains. Seems that just getting the grains to swell is all that is needed at that point and then the HTL does some quick converting.

Yeah, I was surprised to read that the corn granules undergo 'rearranging' of molecules and create new bonds before full gelatinization occurs. Fascinating stuff.

I think a little HTL when mashing in your corn lowers the viscosity enough to help distribute the 'main' HTL (I wait until 190F) dose later on.

revisiting this old but not ancient thread...

I usually add HTL to the hot water before I add the corn meal, so I don't "see" and gelatinization. The mash never puddings up - it stays nice and soupy all the way through. I wrap it up and hit it with a paint stirrer a few times as it goes down to beneath 160, and add raw rye (and often wheat), then down to 145 for the barley malt. I get a good bourbon out it, but I do wonder if my efficiency would be better if I followed the protocols above - will using hotter water make more starches available? should i let the corn meal pudding up before adding the HTL? my ratios are a kilo to 4 liters of water, and I end up in the 1.07 to 1.08 range.