HERMS Corn Mash? Yes! You can!

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Johnnywhiskey
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HERMS Corn Mash? Yes! You can!

Post by Johnnywhiskey »

Let me start off by saying that I'm not advocating this as the easiest or best way to do a bourbon mash (i.e., corn mash). Rather, like many on HD, I run what I brung, and that is a HERMS system that I built for beer brewing. I don't have a distillation system that works well for fermenting on the grain, so laudering the mash to get it off the grain is necessary. I have been amazed at the boost in efficiency that I get when beer brewing with HERMS and hope to utilize that for AG whiskeys mashes.

Just so everyone knows HERMS stands for Heat Exchanged Recirculated Mash System. I guess that part that really matters here is that I use a pump to constantly recirculate the mash in my mash tun with a false bottom and I can use the heat exchanger to maintain the temperature of the mash. I've heard many say that corn mash will just clog a false bottom for laudering, but I have found that to not be the case (done that successfully many times). Now I can say that not only can you lauder, but constantly recirculate of the wort (or beer) without a problem--just add some rice hulls and make sure you have your high temp alpha amylase in the mash while you are gelatinizing your corn. I did the following test run and surprised at how smoothly it went--recirculated the entire time.

10g H2O
14 lbs Milled whole Corn
1 lbs Rice Hulls
3 lbs Rye
3 lbs Malted Barley

The corn and rice hulls went in at about 160F, after adding SEBStar HTL, I brought the temperature up to 180F and held for 90 minutes, added the rye (concerned about the rye gummyness) and held for another 60 minutes. Dropped the temp to 150F and added the malted barley and SEBamyl and held at 145F for another 90 minutes.

I'll sparge and take off 12-13g. Looks like it will be around 1.050sg. Next time I'll do 2.5lbs/g grain and mill the corn a bit finer and I think I can get an even better efficiency without a problem.

Just throwing this out there as a good option for brewing/distillers.

Stay Thirsty, JW
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Re: HERMS Corn Mash? Yes! You can!

Post by NcHooch »

I did it once in a RIMS system by first pre-cooking the corn in the oven overnight.
I ended up doughing in something like 6 pounds of 2-row, and then dropped these big globs of cracked corn pudding on the top of the grain bed....I mashed for 60 minutes @148 and drained and sparged , I recall it ended up 10 gallons at about 6% .
I didn't use rice hulls, but was very careful to avoid disturbing the grain bed.
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Re: HERMS Corn Mash? Yes! You can!

Post by still_stirrin »

JW,

Of course you can HERMS a bourbon mash. Lautering (note the correct spelling), can be challenging unless you use the liquid enzymes to help break down the starches. Remember, you still do need to gelatinize the corn in order to get it to “release its starch”. And you no doubt know about rye malt and its beta glucans (syrupy glue).

And after adjusting your grainbill for brewery efficiency, you’ll attain consistant results. Corn is cheap, so increasing the grain to water ratio is relatively benign.

An electric brewery is a fantastic tool for making beer....and distiller’s beer. I’m envious...the automation and process control is key to repeatability. Have fun...and enjoy a beer too.
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Re: HERMS Corn Mash? Yes! You can!

Post by RandyMarshCT »

Johnny, you are inspiring me. Lautering with corn is something I've always wanted to pull off. I think I might give it another go. How much do you mill your corn? Or do you just cook it cracked?

It will be a little while before I give this a go again, but I'll post my results if I have any luck.
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Johnnywhiskey
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Re: HERMS Corn Mash? Yes! You can!

Post by Johnnywhiskey »

RandyMarshCT wrote:How much do you mill your corn? Or do you just cook it cracked?
I mill my own whole corn with Monster Mill 2.0 roller mill--which can be a pain. If the roller gap is too narrow the corn doesn't get pulled through. The MM 2.0 opens a bit wider than most roller mills for really giant kernels (like the corn Honeyville sells). But I think a regular mill might be able to handle the regular sized corn I'm using know. This test run I milled the corn to slightly finer than cracked corn, and next HERMS run I'll do it even finer--not quite coarse corn mill. In my experience the milling is the largest factor in mash efficiency for corn. I never got good efficiency with store bought cracked corn without further milling

To reliably lauter (non-HERMS) I also had to tweak my process--rice hulls, long siphon hose and change false bottom stands, that I discuss here--http://homedistiller.org/forum/viewtopi ... =3&t=57691.
still_stirrin wrote:Of course you can HERMS a bourbon mash.
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Not sure it is so obvious that HERMS works on bourbon mash. I searched pretty thoroughly before trying it myself, and did not come up with any reports of it working successfully. Sure for single malts HERMS would easily work, but even brewers complain about high adjunct mashes--any 70% corn is a lot of adjunct grain.
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Re: HERMS Corn Mash? Yes! You can!

Post by Born_Free »

Johnnywhiskey wrote: Sun Nov 05, 2017 4:22 pm Let me start off by saying that I'm not advocating this as the easiest or best way to do a bourbon mash (i.e., corn mash). Rather, like many on HD, I run what I brung, and that is a HERMS system that I built for beer brewing. I don't have a distillation system that works well for fermenting on the grain, so laudering the mash to get it off the grain is necessary. I have been amazed at the boost in efficiency that I get when beer brewing with HERMS and hope to utilize that for AG whiskeys mashes.
Old post but wanted to add my 2 cents and say thanks.

First time mashing corn, I decided to try using a 15 gallon herms to gelatinize the corn. I used a large strainer bag in the mash tun just in case it all went to hell. Similar ratios to what you used but no rice hauls. I gelatinized with feed store cracked corn only, did not re-mill, no high temp enzymes, I figured I would just go for it and if stuck I could pull it all out with the strainer bag.

After the corn was gelatinized, it wasn’t necessarily a stuck grain bed, the issue was the liquid was so viscous, my little chugger pump couldn’t maintain much of a flow, just a trickle, even when I pulled the bag to the side effectively removing the grain bed.

Not really a problem, but due to low flow, the mash tun slowly dropped in temp to ~190F. I let it recirculate for ~2 hours.

After cooling down then adding grain and Brewhaus enzymes, the flow picked back up and I could maintain 155F for the conversion. Could have easily sparged but wanted to ferment on the grain.

If the corn had 32 ppg, I was able to extract 75-80%, ending up in the 1.052 range. Looks like you got a little more, but good enough for feed store corn.

Born_Free
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