Low Enzyme/Low ABV Brewing + Party Gyle

[Brooothru]

For several months I’ve been spending the idle hours pondering the potentials and pitfalls of brewing a Low-Enzymatic Mash beer. The process has been out there on the fringe of brewing for a couple of years with some interesting lab and brewery type research, including Briess, that has some good info on their website. For those not familiar with LEM, or if you glanced at it once and brushed it off with a quick, “Oh, that’s “nice,” dismissal, the process involves a hydrolyzing cold mash (more like steeping) at 40F for 4-12 hours in order to extract 90%+ of all the color, flavor, and ‘mouthfeel’ components while leaving behind 75% of the convertible starches.

The grains are removed leaving behind the wort with nearly all the color and flavor components intact, along with a trub-like settled layer of unconverted starches at the bottom. That means that a normal 1.050 OG grain bill from a regular congress mash will result in an actual OG of somewhere around 1.020 and a final ABV 0.5%-1.5% beer that has the taste, color and body of a normally mashed grist. The wort is siphoned off the trub into the boil vessel for a hot mash.

Enough enzymes are recovered in the process to convert the sugars left behind during a subsequent traditional 154F heating mash. After conversion is complete, the temperature is increased to boiling, and a standard brew process is conducted with hops additions, chilling, and knock-out for fermentation. The finished beer has most of the components of a normally produced beer, but with less than a quarter of the ethanol. The conundrum (and opportunity) is how best to recycle the ‘partially’ spent grains for a second party-gyle beer. It seems like adding flaked rice along with white wheat and mashing with the original grist in a second normal congress mash would have more than enough diastatic power to fully convert the mash, especially if the starch dregs from the cold mash were tossed into the mix. At least it should be sufficient to brew a small beer or table beer.

The literature I’ve come across gives a lot of empirical data about color, flavor components, dextrins and the like, but very little about enzymes that remain in the settled trub and spent grains. Has anyone tried this method, particularly the secondary batch? I’d like to hear any experiences or hints for success. Or failures that might convince me to not waste my time.

 

[BrewnWKopperKat]

background: there are four process flows that are described in the "cold extraction" presentation. In addition to HBC 2016, cold extraction was presented at PNWHC 2017 and that slide deck is still publicly available (for those interested, follow this link (link) to a reply that includes the link to the PNWHC 2017).

In addition to low ABV beers and "Malt Monster" (additional link to 2019 reference), there are two additional processes:

• "path 1" uses the "cold extraction" spent grains in a 2nd batch
• "path 2" uses the "cold extraction" wort as the brewing liquor in a second batch

to be continued ...

 

[BrewnWKopperKat]

@Brooothru : do you have access to the HBC 2016 presentation audio?

 

[Brooothru]

Sad to say I don’t have access to the HBC presentation. I do have the Briess power point and will go back to review the various pathways, since it looks like what I want to know is in there somewhere.

Have you tried doing a NEM beer? I think I can use equipment on hand to adapt my process to do this fairly easily. My only concerns are scorching during the hot mash and boil, and how best to get use out of the spent grains in a second brew.

Of course, the main motivation is brewing a good low ABV beer. IMHO, there’s only a handful of them available in the commercial market, and even they don’t always rise to the level of most ‘really good’ full ABV beers.

 

[Alan Reginato]

I've read a lot about it. I was trying to find the articles, but they seem to fell in the black hole that is "my documents"

Anyway I did that NEM beer and it was a disaster, mainly because the combo of insoluble starches and heat element. The scorch was bad. That day was bad. Because of other things too.
I think I might have saved the beer, but was absolutely traumatizing.

Anyway, it worked. I stirred it for one hour. Someone said that 30 minutes are enough. But i didn't let it drop for enough time and didn't separate the insoluble starches initially. So, let time and gravity do their thing and get rid of that insolubles. Or just let it sit overnight, with eventually stirring, should do the trick too After that, mash as usual. It's important, because you will have some starch in suspension. I got 22% mash efficiency, before boil. Check the BU:GU for hops. Only IBU and you might ended up with a overly bitter beer.
The leftovers made their way to the trash. You can use it in another beer, but for everything I read, you should add some base malt, because most, if not all, of enzymes will be gone. Treat it like it's special malt, with no enzymes, and you should be ok.

When you made it, let us know! Good luck!

 

[BrewnWKopperKat]

more background: the NEM path. Note the "Mash @ Temp" step. Many anecdotal brew days heat directly to a boil (skipping the rest) - which seems to result in a lower ABV beer.

 

[BrewnWKopperKat]

@Brooothru : over a number of years, I have tried the "NEM path" a copule of times for lower ABV beers and "path 2" a copule of times for (hopefully) maltier beers.

I have tried "path 1" (mash spent grains) once early on. The result was ok for a 1st attempt. Given how long the brew day / weekend was with two mash/boil steps, I decided to focus on just the "path 2" process. For the path two beer, there's a grain bill in the slide deck (around slide 11). I haven't tried that specific grain bill.

With BIAB, the "cold mash" step can require additional work to get a clearer wort. I use an 1800W induction cooktop with a very slow boil - and scorching wasn't a problem after the 1st couple of batches.

For those curious about the "Malt Monster" process, there is additional information on how to do it in the Q&A section of the audio.

... (maybe) to be continued later this eveing when I have time to check my notes.

The process has been out there on the fringe of brewing for a couple of years with some interesting lab and brewery type research

If you have found newer content (2020 or later), can you share references to it?

The multi-year topic here at HBT (link) has numerous good references, but mostly from the 2016 - 2018 timeframe (as always, try the Internet Archives if the original link is 404).

 

[Brooothru]

I've read a lot about it. I was trying to find the articles, but they seem to fell in the black hole that is "my documents"

Anyway I did that NEM beer and it was a disaster, mainly because the combo of insoluble starches and heat element. The scorch was bad. That day was bad. Because of other things too.
I think I might have saved the beer, but was absolutely traumatizing.

Anyway, it worked. I stirred it for one hour. Someone said that 30 minutes are enough. But i didn't let it drop for enough time and didn't separate the insoluble starches initially. So, let time and gravity do their thing and get rid of that insolubles. Or just let it sit overnight, with eventually stirring, should do the trick too After that, mash as usual. It's important, because you will have some starch in suspension. I got 22% mash efficiency, before boil. Check the BU:GU for hops. Only IBU and you might ended up with a overly bitter beer.
The leftovers made their way to the trash. You can use it in another beer, but for everything I read, you should add some base malt, because most, if not all, of enzymes will be gone. Treat it like it's special malt, with no enzymes, and you should be ok.

When you made it, let us know! Good luck!

Sorry it didn’t go well for you, but I’ll take what you learned from your ‘disaster’ and apply the knowledge to my attempt. Thanks!

 

[Brooothru]

@Brooothru : over a number of years, I have tried the "NEM path" a copule of times for lower ABV beers and "path 2" a copule of times for (hopefully) maltier beers.

I have tried "path 1" (mash spent grains) once early on. The result was ok for a 1st attempt. Given how long the brew day / weekend was with two mash/boil steps, I decided to focus on just the "path 2" process. For the path two beer, there's a grain bill in the slide deck (around slide 11). I haven't tried that specific grain bill.

With BIAB, the "cold mash" step can require additional work to get a clearer wort. I use an 1800W induction cooktop with a very slow boil - and scorching wasn't a problem after the 1st couple of batches.

For those curious about the "Malt Monster" process, there is additional information on how to do it in the Q&A section of the audio.

... (maybe) to be continued later this eveing when I have time to check my notes.


If you have found newer content (2020 or later), can you share references to it?

The multi-year topic here at HBT (link) has numerous good references, but mostly from the 2016 - 2018 timeframe (as always, try the Internet Archives if the original link is 404).

Oh yeah, lots of “404s” in my searches! I went through trying all the links in the HBT necro threads and kept ending at dead ends or repeats of things I’d already come across.

That said, I’m feeling like I could pull it off if I only felt good about knowing how/when the cold mash starches were settled enough to not end up in the boil pot. That seems to be the critical fault area of the process.

I’m thinking that a 12 hour minimum cold mash @ 38~40F, no sparge, pull the grains, let the wort settle for a couple of hours, then drain the clear wort into the hot mash/boil pot leaving a gallon or more of the starchy supernatant behind, might avoid the scorched boil pot issues. That would be the #1 pathway, minus the lauter. Hot mash the wort for conversion, then boil with hops and ferment, with the goal being a very low alcohol beer that has the flavor and body of a traditional IPA/PA, paying close attention to BU:GU ratios, as @Alan Reginato pointed out.

For the spent grains I’d add in roughly 1#/0.5kg each of pilsner and white wheat for their high diastatic power along with a smaller amount of flaked rice and/or maize for flavor and additional sugar. Mash this new grist in a Hoch-Kurz profile to see what kind of yield I get.

I’m also wondering if adding the sediment from the cold mash would result in something useful. If I have ~1gal./4L of ‘wort’ plus the starchy sediment from the cold mash, that slurry should be rich with potential sugars, non-denatured enzymes, and residual amounts of color, flavor and body elements.

My all-in-one Braumeister operates on a continuous recirculation, so the mash would be like a 60 minute vorlauf. Might even toss in a handful of rice hulls to trap sediment particles that might cause scorching on the elements. Maybe this ‘3rd pathway’ would produce an interesting light lager!

 

[Agent]

It's my understanding that the enzymes are water soluble. So in a normal mash where you get 80% extraction efficiency on sugars, your enzymes would likely fare the same way.

In fact, I think one of the possibilities listed is to use the cold extract liquid to convert a 100% adjunct grain bill.

So your extracted grains would still have some enzymes left, but not likely enough to completely convert themselves.

 

[Brooothru]

It's my understanding that the enzymes are water soluble. So in a normal mash where you get 80% extraction efficiency on sugars, your enzymes would likely fare the same way.

In fact, I think one of the possibilities listed is to use the cold extract liquid to convert a 100% adjunct grain bill.

So your extracted grains would still have some enzymes left, but not likely enough to completely convert themselves.

I'm not totally sure about a direct relationship between enzymes (are they soluble, or merely in solution) and efficiency of extraction. I believe that the presence of sufficient enzymes in the mash (whether dissolved or in suspension) is what drives conversion of starches into fermentable sugars. It's the liquid of the mash that makes the starches soluble, thus providing 'fuel' for the enzymes to convert the available sugars into ethanol and CO2. The conversion by the enzymes requires sufficient enzyme amounts, optimum temperature for conversion by the specific enzyme, as well as enough time and proper pH so as to not denature the enzymes before they complete the task.

'Mash efficiency' is a combination of many factors, including grain crust and water:grist ratios as well as time, temperature and amount of enzyme available once the starches become hydrolyzed. What's not clear to me what the distribution of enzymes within the wort column actually is. Is it uniform throughout, does it stratify, does its distribution vary with temperature (density). I'd like to think the distribution of enzymes is essentially even throughout the column, but I can see how different factors could suggest otherwise. That's why I'm curious to see if I could expect "a little" or "a lot" of enzymes present in the sediment and supernatant left behind (hopefully, to avoid scorching) in the cold mash tun. If so, that 'discard' would be a useful source for additional enzymes for a second mash. It would also dictate how much additional high diastatic malt I should estimate to augment the second mash in order to have enough enzyme present for a more complete conversion. So my question is actually, "How much enzyme might there be in a gallon or so of the settled cold mash liquid and 'trub'?"

The spent grains will still contain some unconverted starches from the cold mash since I'm not sparging. They will get 'rinsed' by the second mash strike water and be available for the enzymes present and those provided by the new high diastatic power grains to be converted. I just don't know how much more 'sugar' needs to be provided by new grist, though in theory only 25% of the sugar from the cold mash made it into the NEM fermenter. And neither do I know how to estimate how much enzyme is needed for the second mash. I guess it'll end up being a 'best guesstimate" and trial & error. I'll take copious notes and report back.

 

[BrewnWKopperKat]

Someone said that 30 minutes are enough.

Back in Oct 23 (link), I did a short-and-shoddy cold extraction (give the grains a stir every 15 minutes for about an hour), then separate the grains from the wort, then holding the wort cold overnight to let gravity do it's thing. I got an acceptable amount of extract. Could I have got more extract by cold mashing longer?

Part of my reason for doing this was curiosity around "cold extraction (base malts)" and "cold steep (crystal / roasted malts)".

I've also done some cold steeping of crystal / roasted malts (brief stir every 5 minutes) - and find that almost all the color / sugars is extracted.

There are differences in the "mash thickness" (cold steep vs cold extraction) that might account for the desire to do a longer "cold extraction" process.

 

[BrewnWKopperKat]

@Brooothru : the one time I tried "path 1" ...

... I assumed the spent grains had no DP. The "hot mash" had at least 1 lb of fresh base malt for each pound of "spent grains". The DP of the hot mash was probably in the 60-70 range, so I mashed for an hour. The beer came out OK, but it was a very long (for me) brew day.

 

[Brooothru]

Back in Oct 23 (link), I did a short-and-shoddy cold extraction (give the grains a stir every 15 minutes for about an hour), then separate the grains from the wort, then holding the wort cold overnight to let gravity do it's thing. I got an acceptable amount of extract. Could I have got more extract by cold mashing longer?

Part of my reason for doing this was curiosity around "cold extraction (base malts)" and "cold steep (crystal / roasted malts)".

I've also done some cold steeping of crystal / roasted malts (brief stir every 5 minutes) - and find that almost all the color / sugars is extracted.

There are differences in the "mash thickness" (cold steep vs cold extraction) that might account for the desire to do a longer "cold extraction" process.

One sub-topic, re: NEM, that supposedly has a large impact on the final beer is yeast. Some references suggest using one that is expressive of esters to prevent the beer from being bland. Belgian style yeasts like Belle Saison were suggested.

I don’t have much (any) experience with Belgian styles (just not my thing), but I was thinking a more estery British yeast at a slightly higher fermentation temperature would fit the bill. Maybe a dry yeast like Verdant can be used.

Any suggestions from the ‘braintrust’? I usually go for clean/dry performance with yeast, so this ingredient is outside my wheelhouse.

 

[Agent]

My previous batch was a porter grainbill with one of the Omega British Ale versions and I really liked how that turned out.

My current version was a similar grainbill but with an old pack of Thames Valley. That came out sort of musty and gross, so I think I just had a goof somewhere.

 

[beersk]

My previous batch was a porter grainbill with one of the Omega British Ale versions and I really liked how that turned out.

My current version was a similar grainbill but with an old pack of Thames Valley. That came out sort of musty and gross, so I think I just had a goof somewhere.

I could see this working really well in a porter. I did a vienna lager first then a pilsner. This was back in 2020 and I didn't care much for how the beers turned out. The vienna lager was better than the pilsner. This process extracts a very specific and unique flavor from the grains and both of my beers tasted very similar in that way. Curious to see if people experiment further with this and can find a way to produce great results.

 

[youngdh]

My last batch of my NEIPA finished at 3.2% ABV fermented with Omega Hornindal Kveik at 95° F. I targeted my grain bill for 3.5% ABV and then mashed hot at 162° F to further limit fermentables coming out of the mash. I also adjust my BU:GU ratio for my hop bill. The beer has good mouthfeel and nice flavor for a lower ABV bill.

 

[BrewnWKopperKat]

One sub-topic, re: NEM, that supposedly has a large impact on the final beer is yeast. Some references suggest using one that is expressive of esters to prevent the beer from being bland. Belgian style yeasts like Belle Saison were suggested.

IIRC, there were a couple of /r/homebrewing topics from 2017/2018 that reported good results with low (< 3%?) ABV saison recipes.

I don’t have much (any) experience with Belgian styles (just not my thing)

It's not my thing either.

Maybe a dry yeast like Verdant can be used.

@beersk (above) mentioned "unique flavor from the grains".

When I was "experimenting" with low ABV recipes (using cold extraction), Lallemand Verdiant (and New England) were not available.

Maybe Verdant is a strain (beyond Belgian style yeasts) that provide yeast flavors that complement those 'unique to us' grain flavors.

 

[mashdar]

Early 2023 I used a cold extraction to make some <1% milds. It was okay, but lately I've been working on other recipes.

A few notes:

After removing grain, I strongly recommend giving it time to settle and transfer off the starch. Drives down ABV more, and avoids massive scorching.

pH was not low enough for food safety (4.6) at <1.5% ABV. If going that low, consider pH adjustment.

I put crystal malts and dark malts in the sacc rest instead of cold extract step. I didn't do enough variations to say if it mattered.

Predicting OG was tough, and FG was even harder. Expect very low attenuation.

edit: Oh yeah, also see this Cold Extraction of Malt Components and Their Use in Brewing Applications - Brewing With Briess

 

[beersk]

Early 2023 I used a cold extraction to make some <1% milds. It was okay, but lately I've been working on other recipes.

A few notes:

After removing grain, I strongly recommend giving it time to settle and transfer off the starch. Drives down ABV more, and avoids massive scorching.

pH was not low enough for food safety (4.6) at <1.5% ABV. If going that low, consider pH adjustment.

I put crystal malts and dark malts in the sacc rest instead of cold extract step. I didn't do enough variations to say if it mattered.

Predicting OG was tough, and FG was even harder. Expect very low attenuation.

edit: Oh yeah, also see this Cold Extraction of Malt Components and Their Use in Brewing Applications - Brewing With Briess

Yeah, the scorching thing is real. I just stirred constantly and didn't get any scorching, but if you let up even for a minute, you will get scorching. It's kind of tedious.
And maybe I didn't adjust the pH that's why I got the flavor I did. But I'm kind of doubting that. Seems that flavor was process driven rather than something else. I could see it working well in yeast forward beers. I brewed lagers with it and that was probably not the best choice for this method.

 

[Brooothru]

Early 2023 I used a cold extraction to make some <1% milds. It was okay, but lately I've been working on other recipes.

A few notes:

After removing grain, I strongly recommend giving it time to settle and transfer off the starch. Drives down ABV more, and avoids massive scorching.

pH was not low enough for food safety (4.6) at <1.5% ABV. If going that low, consider pH adjustment.

I put crystal malts and dark malts in the sacc rest instead of cold extract step. I didn't do enough variations to say if it mattered.

Predicting OG was tough, and FG was even harder. Expect very low attenuation.

edit: Oh yeah, also see this Cold Extraction of Malt Components and Their Use in Brewing Applications - Brewing With Briess

Excellent. Just the kind of personal experience and brew notes I am looking for.

 

[aeviaanah]

Excellent. Just the kind of personal experience and brew notes I am looking for.

How’s this process working out for you? I’m looking to try the hot mash (176F) method curious if I should try cold mash followed by mashing in the boil kettle. I haven’t brewed an NA or low ABv beer to date

 

[Brooothru]

Six inches of snow have put my brewing on hiatus, so no progress yet. That, plus life catching up with me, keeps me from getting this done and in the fermenter.

But to your question, the ‘cold mash’ is actually a cold extraction of flavor, color and mouthfeel components, but leaving only about 25% of the starches. Those starches need to get converted to fermentable sugars. To do that, you’ll have to take the wort from the cold ‘mash’ (extraction) and then heat it as you would a normal congress mash. Then you would boil it with hops, followed with fermentation.

So the cold mash is actually an extra step used to separate a major portion of the fermentables from the wort so that the final beer will have less ABV.

 

[BrewnWKopperKat]

related: Feedback on non-alcoholic recipe and process