Tuesday, March 28, 2017

Non Enzymatic Mashing, Take 1

Today the local homebrew shop owner and I brewed the partigyle method of a Non Enzymatic Mash (NEM), aka, cold mashing. I outlined this process HERE.

The partigyle method is to cold soak your grain overnight, then extract off the cold wort into your kettle, sparge with more cold water until you hit your preboil volume, then heat this cold wort through your typical mash temperatures to convert any starches to fermentable sugar.

The reason for the cold mash is that a beer's enzymes, body, and color are all cold soluble and will be extracted via this cold method, yielding a beer that contains only 25% of the starch, yet ALL of the enzymes, and most of the color and body, leaving behind "spent grain" that contains 75% of the starch, yet zero enzymes, and very little body and color.

The cold mashed beer is good for creating a session beer: low in alcohol, but high in body and color. The spent grain is then hit with hot water and traditionally mashed, giving you a high sugar, low body and low color beer: think Belgian Golden Strong or Belgian Tripel.

Here are our findings:

Overnight Mash
The shop owner mashed the grain bill, 16 pounds of equal amounts of Mecca Grain, into a large bucket with 2 qts/lb of water. He left it sit overnight at a cold temperature.



The next morning I joined, and the mash was very very fragrant. It was more on the grassy and vegetal side of the aroma spectrum than a caramel aroma from a typical hot mash. The lauter went easily with no issues of a stuck mash, since the mash never fully gelatinized. The color of the wort was a nice amber.



We tasted this wort and it was sweet. Not just sweet as in a surfer dude hitting a wave and his buddy going, "SWEET, BRO!" but it was actually sugary sweet, like some conversion actually happened at a cold temperature. We were wondering just how much conversion actually occurred with just how sweet it was.

Lauter and analysis
After the lauter to a pre boil volume of 6 gallons, a gravity measurement showed 1.022. Pretty low for the sweetness we were tasting, but! this number makes sense. Given 16 pounds of grain, that should yield a potential in the 1.08X range, so 1.022 is roughly 25%. The folks at Briess weren't lying!

So what accounted for that sweetness despite the low gravity reading? We are guessing body. Body was making up for that sweetness.

Boil
We treated the beer as a session Americal Pale Ale and used 100% Citra hops with the following schedule:

90 min boil
1 oz @ 60 mins
1.5 oz @ 10 mins
1.5 oz @ 0 mins

The final gravity yielded 1.028.



Spent Grain
While the session beer was starting its boil, we dealt with the leftover spent grain which still contained 75% starch.



We were unsure just how many enzymes were left, so we did a starch test after we got the temperature into saccharification range. The starch test, using iodine, was negative. Bummer. There were no enzymes available. So we hit the mash with some liquid enzyme, but to no avail. The mash did not want to convert! Fortunately we had some Distiller's malt, and we used 2 pounds and that did the trick as a positive iodine test ensued.




So that pretty much settled it re: enzymes. The cold mash literally sucked out 100% of the enzymes needed for conversion. We figured there had to be some enzymes left. Nope! Nada.

For this remaining mash, we lautered and made a Belgian Tripel. The pre boil gravity was 1.050, while the finishing gravity was 1.067. We used a combination of Mt Hood and Crystal hops.

Control Beer
Meanwhile, another associate at the brewshop made a "control" beer of the American Pale Ale: single infusion beer with the same grain bill and the same hop schedule.

Never seen a Grain Father in action.

Will be interesting to see how both beers compare once they are done.

Takeaways
The two biggest takeaways of this process were division of starch and the extraction of enzymes. Briess reported that 25% of starch will extract via the cold mash, leaving 75% behind. They also reported that all enzymes will be extracted as well via the cold mash. We confirmed both of these findings.

What differed from their findings was beer color. The Tripel (even before adding the distiller's malt for conversion) still had quite a bit of color. It was lighter than the session beer, but not completely colorless. I find it not to be that big of a deal re: color. Color is merely for show.

Would I do this method of NEM again? Sure! It takes some preplanning, but to get a session beer and a bigger beer out of one mash is a neat time saving trick, especially if your session beer gets way more body than a traditional mash.

Will report back on the beers once they are finished fermenting.

2 comments:

  1. Just boiling a mini batch of a similar recipe using the cold mash. How did yours come out?

    ReplyDelete
  2. Man, thanks for your posts, but, what was the oucome of the experiment?

    ReplyDelete