Low Enzymatic/Cold Mash/Low alcohol beer

[kmarkstevens]

It was fine and prolly worth fine tuning. I used a 3 gallon keg, so from first pitch to kicking the keg was a week or so.

actually, I didn't track how long it took but a really quick ferment and 3 gallons of ultra low ABV didn't take long to quaff.

 

[beersk]

Dang! You must've been drinking that like mad to finish it off in a week. That was the nice thing about the one good Vienna lager I made with this method last year. I could drink pint after pint of it and not be affected at all at 1.5% abv. Sure, it wasn't as good as my normal Vienna, but it wasn't far off, and could probably get pretty close with a few tweaks. I know I left out any caramunich or crystal malt in that beer and it could've used just a tad of sweetness. That was my one note from that recipe. I think this winter after my 2 month break I'll start playing with this again. I think it could work well for something like schwarzbier perhaps. I'd be curious how a pale ale or IPA would work with it; black IPA might be a good place to start.

 

[kmarkstevens]

beersk, you've gotten me reinterested in this. So, gonna revist a couple of enzymatic mashes. Another mix of vienna, munich and something. maybe even something with a bit of chocolate, black or roasted barley....Definately, brewpot to keg works and will be my SOP

I'll also try the hot mash again.

David Heath Homebrew, who I quite like, has a hot mash (179F) IPA recipe: (169) Low Alcohol IPA Homebrewers Full Guide and Recipe - YouTube
(Note: Most american and C hops simply taste like cat piss to me, so I really don't like American IPA's, but that's my problem. Anyhoo, David shows the way to what looks to be a decent lightwieight IPA if that's your thing)

 

[shoreman]

That recipe above looks interesting, I’m getting back to some low ABV brewing. Wonder if anyone here has brewed it? I’m not a lactose fan and was thinking about subbing an adjunct like rye or wheat?

How important is ph in this beer for stability? I see he uses acidulated malt for ph reasons.

 

[beersk]

That recipe above looks interesting, I’m getting back to some low ABV brewing. Wonder if anyone here has brewed it? I’m not a lactose fan and was thinking about subbing an adjunct like rye or wheat?

How important is ph in this beer for stability? I see he uses acidulated malt for ph reasons.

I would imagine pH is probably pretty important, but I don't know, especially if it's to be kegged and stored cold for the life of the beer. Rye or wheat would probably be a good thing to include, flaked or whole.

 

[beersk]

I'm thinking to add a pound of wheat into every recipe. I think after my 2 month break from alcohol I'll start experimenting with this again, just 2.5 gallon batches. I do remember the Vienna lager I made last year being decent, only lacking a little sweetness. My fix for that, I think, is to add some C60 or Caramunich. I think this method is totally doable with: characterful yeast, using more end-of-boil hops (quite a bit less bittering), and making sure to use specialty malts to our advantage.
I don't have a definitive answer but my anecdotal experience is it doesn't necessarily suit beers like helles or pilsner. It does change the malt character quite a lot. It's more grainy. And styles that have caramel/roasted malts I think would benefit from this as well as something like hefeweizen; that's one style I'm really excited to try this out on.

 

[kmarkstevens]

good on ya for a 2 month break. I think this enzymatic really has promise, and most folks like myself haven't dug in to really find a couple of killer recipes that does it justice. I'm with you that it comes out grainy, and one shouldn't try to force fit it with more subtle styles.

I do remind people that be careful of scortching! I am fine after getting a 400 micron BIAB bag, but the first attempt was simply awful burned vegetal taste.

What about doing this as a table saison? I'm thinking that might be pretty good.

 

[BrewnWKopperKat]

maybe table saison as the "killer recipe"? Back in 2018-2019 in one of the other home brewing forums, there were a couple of very popular topics on 1.5% - 3.5% saison recipes. Might be a link in my "link dump" back in #10 in this topic.

 

[beersk]

I mashed in on an Irish Red a while ago, 3.5 gallons, brew in a bag (voile, fairly fine), mashing at 73F for 4ish hours, stirring as often as possible.
6lbs Maris Otter
8oz C40
8oz Special Roast
3oz Light Roasted Barley
.25oz US Goldings 30min FWH
.5oz US Goldings 5 min
Verdant IPA yeast

Benefit to working from home. It took no time at all to get mashed in. Just milled grains right into the kettle with the water and bag already in it. We'll see how it turns out. But I'm hoping to avoid the uber grainy flavor I got in my batches I made last year. If not, I'm not sure what I'll do going forward.

My plan is to bring it to the 150s for about 30 minutes. Boil for 30 minutes. Then ferment and serve in a 5 gallon keg with a floating dip tube and serve on nitro. Looking forward to see how that turns out. Really simple process. If this turns out a good beer that I want to drink guilt-free pints of, I'm definitely scaling up to 4.5 or so gallons, still ferment and serve in a keg. Would be awesome.

 

[beersk]

I mashed in on an Irish Red a while ago, 3.5 gallons, brew in a bag (voile, fairly fine), mashing at 73F for 4ish hours, stirring as often as possible.
6lbs Maris Otter
8oz C40
8oz Special Roast
3oz Light Roasted Barley
.25oz US Goldings 30min FWH
.5oz US Goldings 5 min
Verdant IPA yeast

Benefit to working from home. It took no time at all to get mashed in. Just milled grains right into the kettle with the water and bag already in it. We'll see how it turns out. But I'm hoping to avoid the uber grainy flavor I got in my batches I made last year. If not, I'm not sure what I'll do going forward.

My plan is to bring it to the 150s for about 30 minutes. Boil for 30 minutes. Then ferment and serve in a 5 gallon keg with a floating dip tube and serve on nitro. Looking forward to see how that turns out. Really simple process. If this turns out a good beer that I want to drink guilt-free pints of, I'm definitely scaling up to 4.5 or so gallons, still ferment and serve in a keg. Would be awesome.

Well, I ended up having to dilute this anyway as my preboil OG was 1.028, higher than I wanted obviously. I diluted with 1 gallon of RO to get it up to 5 gallons preboil, up from 4, and down to a gravity of 1.020. Oh well, all else seemed like a normal beer that was mashed hot, smelled and looked the same all around. One thing I noticed was it wasn't nearly as dark as it should be. More of an amber color instead of a deep red.

 

[kmarkstevens]

@beersk Awesome. Thanks for sharing. Will be following your results.

I've got a whole list of things to brew, so after I get some of those knocked off I do want to try the enzymatic again.

@BrewnWKopperKat Cool links. Yep, I copied the Saison and it's on that long "to brew" list

 

[beersk]

Well, I ended up having to dilute this anyway as my preboil OG was 1.028, higher than I wanted obviously. I diluted with 1 gallon of RO to get it up to 5 gallons preboil, up from 4, and down to a gravity of 1.020. Oh well, all else seemed like a normal beer that was mashed hot, smelled and looked the same all around. One thing I noticed was it wasn't nearly as dark as it should be. More of an amber color instead of a deep red.

I took a gravity reading/sample of this today. 1.024 down to 1.008 for about 2.1%, higher than I wanted. But, it tastes pretty good and has a great aroma, very British. I put the keg into the kegerator and will hook it up to beer gas in a day or so. It has a nice full body, definitely not thin tasting, and doesn't have the funky graininess I've gotten before. I'd call it a success. It's much lighter than I was aiming for, more of the color of a marzen, but that's OK. I'm going to do a black IPA next.

 

[Miraculix]

I took a gravity reading/sample of this today. 1.024 down to 1.008 for about 2.1%, higher than I wanted. But, it tastes pretty good and has a great aroma, very British. I put the keg into the kegerator and will hook it up to beer gas in a day or so. It has a nice full body, definitely not thin tasting, and doesn't have the funky graininess I've gotten before. I'd call it a success. It's much lighter than I was aiming for, more of the color of a marzen, but that's OK. I'm going to do a black IPA next.

Sounds pretty much perfect to me!

 

[beersk]

Sounds pretty much perfect to me!

Let's hope!

I should note, I fermented this under pressure as well. Started at about 1-2 PSI, then raised to .5 bar (6PSI) after a day or so and left it there. So that may have helped with the body. Maybe.

 

[kmarkstevens]

@beersk sounds great. I'm gonna have to get low enzymatic back into the rotation

 

[beersk]

@beersk sounds great. I'm gonna have to get low enzymatic back into the rotation

I think it's worth it. I'm looking forward to experimenting with it more. I'm working on a theory that leaving it for 12+ hours makes it taste grainier, but I'm not hard set on that just yet. I'd like to try a helles or pilsner again with the 4 hour mash, stirring often (basically every time I get up from my desk) and see if it comes out any smoother. It definitely did not extract as much color as I was expecting, so adjustments need to be made there.
But I'll know more once I actually tap this beer. This is all based on the sample before I moved it to the kegerator. But if it tastes good warm, it's usually better cold and carbonated.

 

[beersk]

Update on the Irish Red. I'd call it a success. A close brewing friend of mine also thought it tasted very good. He wouldn't have guessed it was 2% abv. It was supposed to be more like 14 SRM, but this is more like 10-12 SRM, I'd say. Still tasty, great aroma and flavor, awesome head retention (the nitro helps). I think you can tell it's lacking a bit of something [the alcohol] but it's solid. Definitely going to explore this further. Black IPA next up.
For lighter styles/lagers, I'm thinking of maybe trying the hot mash technique and maybe with an OG around 1.030, finishing in the 1.010s somewhere for dextrins and mouthfeel.

Given that I'm only a month into my break, I probably won't drink much more of this in the next month, maybe one or two. Maybe. But I'm excited for the brewing future.

 

[hamachi]

I ran across this thread a couple of weeks ago and was instantly intrigued by the prospect of a low-ABV/high-flavor brew. I love my Belgian quads, but they are not the ideal beverage for losing the weight I gained over the past 18 months. Yesterday was my first attempt at low-T mashing. Here's my report:

I do mash-in-a-bag (MIAB) in a 10 gallon cooler. My target was a 2.5 gallon batch with OG=1.020. As suggested here and elsewhere, I plugged in 25% efficiency to the Brewer's Friend calculator to develop the following grain bill:

4.5# Maris-Otter
0.5# Aromatic
0.25# Crystal 75

I chilled the strike water to 58 degrees F. After dough-in, the temp was 63 F. Over 3.5 hours, I stirred occasionally and then lifted the bag. Left behind was a very cloudy, starchy suspension. After draining off the wort, a fair bit of starch sludge was left behind in the cooler. A small amount of additional starch came out of suspension in the pot. I followed with two batch sparges. For each running, I attempted a gravity measurement with a refractometer. In all cases, it was hard to get an accurate reading because the field was blurry. But for the record, here they are:

Running	Volume (gallons)	Approximate Gravity
1	1.85	1.017
2	1.3	1.007
3	1.05	1.004

I heated the 4.2 gallons to 152 F and turned off the electric burner. Over the next 25 minutes, the temperature rose to 154 then dropped to 148, at which point I turned the heat back on. I took another gravity measurement, and it was 1.021. Oops! Too high! This equates to 1.035 at 2.5 gallons (though I have found that these simple calculations are typically overestimates). Clearly there was more starch in suspension that got converted than I had hoped.

To keep the gravity reasonably low, I decided to boil down to ~3 gallons rather than 2.5. In the end, after boiling, chilling, and filtering, I ended up with 3.1 gallons of wort with OG=1.026 as measured by a hydrometer. I pitched a pack of WLP002 yeast and it's now bubbling away.

The Brewer's Friend calculator indicates that my actual efficiency was 41% -- much higher than expected. The issue I think is that I didn't make much of an attempt to limit the amount of starch in suspension or let it settle, especially after sparging. Next time, I will try giving at least 30 minutes for the starch to settle after lifting the bag. For now, it looks like I will end up with a 2-3% beer rather than my target of 1-2%.

 

[beersk]

I ran across this thread a couple of weeks ago and was instantly intrigued by the prospect of a low-ABV/high-flavor brew. I love my Belgian quads, but they are not the ideal beverage for losing the weight I gained over the past 18 months. Yesterday was my first attempt at low-T mashing. Here's my report:

I do mash-in-a-bag (MIAB) in a 10 gallon cooler. My target was a 2.5 gallon batch with OG=1.020. As suggested here and elsewhere, I plugged in 25% efficiency to the Brewer's Friend calculator to develop the following grain bill:

4.5# Maris-Otter
0.5# Aromatic
0.25# Crystal 75

I chilled the strike water to 58 degrees F. After dough-in, the temp was 63 F. Over 3.5 hours, I stirred occasionally and then lifted the bag. Left behind was a very cloudy, starchy suspension. After draining off the wort, a fair bit of starch sludge was left behind in the cooler. A small amount of additional starch came out of suspension in the pot. I followed with two batch sparges. For each running, I attempted a gravity measurement with a refractometer. In all cases, it was hard to get an accurate reading because the field was blurry. But for the record, here they are:

Running	Volume (gallons)	Approximate Gravity
1	1.85	1.017
2	1.3	1.007
3	1.05	1.004

I heated the 4.2 gallons to 152 F and turned off the electric burner. Over the next 25 minutes, the temperature rose to 154 then dropped to 148, at which point I turned the heat back on. I took another gravity measurement, and it was 1.021. Oops! Too high! This equates to 1.035 at 2.5 gallons (though I have found that these simple calculations are typically overestimates). Clearly there was more starch in suspension that got converted than I had hoped.

To keep the gravity reasonably low, I decided to boil down to ~3 gallons rather than 2.5. In the end, after boiling, chilling, and filtering, I ended up with 3.1 gallons of wort with OG=1.026 as measured by a hydrometer. I pitched a pack of WLP002 yeast and it's now bubbling away.

The Brewer's Friend calculator indicates that my actual efficiency was 41% -- much higher than expected. The issue I think is that I didn't make much of an attempt to limit the amount of starch in suspension or let it settle, especially after sparging. Next time, I will try giving at least 30 minutes for the starch to settle after lifting the bag. For now, it looks like I will end up with a 2-3% beer rather than my target of 1-2%.

This mirrors my experience on mine as well, I had about 40% efficiency. I ended up diluting to get to my gravity. The flavor and aroma are good but the beer is...a bit anemic maybe if the best description I can think of. It is pretty good, but if one were to get 40% efficiency and get a 2% abv beer, you can make that low of an abv beer with a regular mash schedule. So I'm contemplating...

EDIT: I don't want to discourage anyone from trying this as I believe it is worth pursuing. But honest notes and thoughts are warranted as well.

 

[hamachi]

I had a much more successful attempt today at cold mash brewing. Today's recipe was a Belgian Helft (Dutch for "half", by comparison to the much stronger dubbel or tripel). To cut to the chase: I ended up with 2.7 gallons of wort at 1.019 OG, for a calculated efficiency of 28%.

The main differences from my attempt a week ago (see posting above):

• No sparge (4.5 gallons cold strike water yielding 3.75 gallons wort at a pre-conversion gravity of 1.011).
• After 3 hours of cold mashing, lift the bag and wait 45 minutes for insoluble starch in suspension to settle out before draining cooler.
• Grist dominated by specialty malts
• Slightly higher conversion temperature to reduce fermentability and hopefully leave more body
• Pitched some WLP530 slurry harvested from a previous batch

Omitting the sparge step and letting the cold wort settle clearly had a major effect. There was much more starchy sludge left behind in the cooler compared to last time. I'm optimistic about this one. If my FG hits 1.004, then I will have a 2.0% ABV 60-calorie beer with hopefully some decent flavor.

 

[ThirstyPawsHB]

1st shot at this NEM. Dubbel with OG at 1.024. I added 1/2lbs of d-90. Grain bill would normally be a 5-5.5%er. Calculations come out at 1.75% max. 4 weeks to report back.

 

[hamachi]

Here's a report on how my two previously described attempts at cold mashed beers turned out:

Attempt 1: LoMash Bitter. Finished at FG=1.009 for ABV=2.2%, calories=85 per 12 oz. Tastes like a reasonably flavorful session bitter. Looks like this:

Attempt 2: Belgian Helft. Finished at FG=1.006 for ABV=1.7%, calories=61 per 12 oz. Tastes pleasant, but with no "Belgian" character that I could detect. A bit thinner than the bitter, as one would expect. Looks like this:

Overall, I am pleased with the results and would call the experiment a success. However, it's a fair bit of extra time and work, and it consumes an excessive amount of grain relative to what you end up with. So as a control, I plan to do another experiment targeting a 2% beer with conventional mashing by simply scaling back the amount of grain. Will the resulting beer be noticeably thinner and less tasty? We'll see.

 

[kmarkstevens]

Thanks for reporting back your results. Looks good!

 

[ThirstyPawsHB]

Here's a report on how my two previously described attempts at cold mashed beers turned out:

Attempt 1: LoMash Bitter. Finished at FG=1.009 for ABV=2.2%, calories=85 per 12 oz. Tastes like a reasonably flavorful session bitter. Looks like this:
View attachment 750727

Attempt 2: Belgian Helft. Finished at FG=1.006 for ABV=1.7%, calories=61 per 12 oz. Tastes pleasant, but with no "Belgian" character that I could detect. A bit thinner than the bitter, as one would expect. Looks like this:
View attachment 750728

Overall, I am pleased with the results and would call the experiment a success. However, it's a fair bit of extra time and work, and it consumes an excessive amount of grain relative to what you end up with. So as a control, I plan to do another experiment targeting a 2% beer with conventional mashing by simply scaling back the amount of grain. Will the resulting beer be noticeably thinner and less tasty? We'll see.

Thanks for reporting back. I started warming WY3787 to 75-78F and got great esters (with normal beers). I'm not familiar with 530 but maybe try the same technique? I've tried low ABV normal mash technique and it's awful. Can't even call it hop water. Thin and tasteless as fuuk. I may report back sooner then expected. Seemed to finish in a couple days. Plan is to brew a regular 10%er Quad on top of this yeast...but for a different thread.

 

[ThirstyPawsHB]

For low ABVs...need to get @TwistedGray involved. This dude can brew flavorful and creative ABVs.

 

[ThirstyPawsHB]

Belgian "Dubbel" ended at 2.5%. This is fantastic!! Get great esters as I fermented warm. Maybe not do the 10% but do another of these adding tart cherries. Truly TRULY excited to keg. And really, 5 days fermentation??!!?? Should be better with some carb. Will report back...

 

[ThirstyPawsHB]

Here she is. Belgian Dubbel bill but using non-enzymatic cold mash technique. 7 days Grain to Glass. Force carbed 3hrs ago. Great body, surprisingly. To recap, 1.024 to 1.005. 2.5% ABV. 78 calories. 5 carbs according to various calculators. A bit grainy as others said about theirs. Wy3787 esters coming through. I'll chalk this up to a successful 1st low ABV brew.

 

[Brooothru]

For the last several days I've been mucking around this thread topic in preparation of making 2022 a Low Alcohol year. I read Jennifer Talley's book front to back and started getting excited, then fell into the rabbit hole of this thread as well as most of the associated links. I really want to try the cold extraction/low-enzymatic mash techniques, but still have a few questions and concerns. Perhaps @ThirstyPawsHB, @beersk, and especially @BrewnWKopperKat (whose comments and links have been especially enlightening) can lend lend a hand and offer up some practical advice.

First question is about wort turbidity and associated 'grainy' perception of the finished beer. In general, I've got a serious hang-up about clear beer. Don't know why, just am. Clear West Coast IPAs, Pales, Blondes and 'brilliant clarity' Continental lagers are my jam. NEIPAs and/or just about anything else that's murky, not so much. In low temperature mashing it appears to be a common comment that once the grains are removed, there's a metric crap-ton of solids left behind. Since I abhor siphon tubes and generally try to perform closed transfers under pressure, will the solids settle out if I cold crash the wort, and if so will the sediment bed be too deep to transfer with a rotatable racking arm? What I'm thinking about is mashing in a temperature controlled conical fermenter, pulling a BIAB mash bag with the grains after 8 hours cold soaking, crashing the remaining wort to the 30s F, dumping the supernatant out the bottom, and then transferring the wort to the mash tun.

It looks like the best profile for mashing is somewhere in the high 150s F to low 160s F to minimize beta amylase from converting too many starches to sugars while maximizing alpha amylase activity for body and mouthfeel. Is there clearing of the wort during mash? Most of the links I read mentioned that turbidity in the wort leads to scorching in the boil pot. The Briess powerpoint had a picture showing a gravity drain transfer from the mash vessel to the boil pot, and it looked like Soylent Green! Other examples showed separated and stratified layering of the wort, a bit thicker than my typical mashes, but low enough that a racking arm should be able to transfer from above the sediment. I just want to have non-viscous wort that doesn't have the color and consistency of a kale smoothie.

After conversion, transfer to the boil pot. Hops on schedule (50% of normal amount for lower IBUs to maintain balance). Concentrate on late hops. Chill, whirlpool (more hops), transfer to my unitank, oxygenate and pitch some Wyeast 1318. Is that about right? My goal is to brew something tasty and satisfying that comes in 2.5%~3.5% ABV with balanced body and hops, preferably clear. Any helpful hints or insights are appreciated.

 

[BrewnWKopperKat]

@Brooothru : I haven't brewed with this technique for a couple of years (so no additional insights and no new links to additional quality articles elsewhere). At that point, my interests in the technique involved the "spent grains", not the wort.

 

[Brooothru]

@Brooothru : I haven't brewed with this technique for a couple of years (so no additional insights and no new links to additional quality articles elsewhere). At that point, my interests in the technique involved the "spent grains", not the wort.

Yeah, that piqued my interest as well; i.e., using spent grains as a sort of "reverse parti-gyle". Since the bulk of the beta and alpha amylase are still in the grain bed, throw in your favorite mix of adjuncts that typically lack the diastatic power to self convert, along with a few handfuls of your favorite base grain, and do a traditional warm mash for a very flavorful low gravity wort. Two mashes for the price of one yielding two low alcohol (but full body and taste) beers. Win-win.

I think my biggest hangup with undertaking a cold mash is the post-mash runnings being viscous and murky before heating, and whether settling the runnings will result in enough separation of solids before boiling. I'll be heating and boiling in an all-in-one electric setup, and I don't want to have this experiment result in scorching and an hours-long cleanup session.

 

[hamachi]

It looks like the best profile for mashing is somewhere in the high 150s F to low 160s F to minimize beta amylase from converting too many starches to sugars while maximizing alpha amylase activity for body and mouthfeel. Is there clearing of the wort during mash? Most of the links I read mentioned that turbidity in the wort leads to scorching in the boil pot.

My process is different from yours in that I did the cold mash for a few hours in a bag inside a 10 gallon cooler, lifted the bag and waited for suspended starch to settle out, then drained the wort into the boil pot. At this point, the wort was still quite cloudy. But to answer your question: Once I heated the pot to the conversion temperature of 150+ F and left it there a while, the wort became MUCH clearer, to the point that it looked to me like "normal" wort during the boil.

Because I gave the starch time to settle out, left so much of it behind in the cooler, and stirred the pot periodically while heating, I had no problem with scorching. If you don't settle and remove the starch sludge after the cold mash , I can see scorching as a problem on the one hand, or too high an OG on the other hand (e.g., if you stir to avoid scorching, which then results in the previously settled starch being converted). Alternatively, if you stir to avoid scorching but spend too little time in the 150-160F range, I could see how you would end up with both cloudy wort and grainy tasting beer due to incomplete conversion. In short, I think finding a way to settle and remove the starchy sludge after the cold soak is crucial for successful cold-mashed low ABV beers.

 

[kmarkstevens]

I haven't done this for quite a while.

1. I now use a 400 micron brew in a bag bag. Once I started using that it didn't scorch. But I sure scorched the hell out of my fast batch pre-400 micron bag
2. I did several batches using the spent grains + 6-row. Came out fine but not a superlative beer. I should try an AK recipe with spent grains, 6-row, bit of corn, English hops and see how that goes

I keep checking in on this thread and prolly will take a few runs again in the summer. A saison might be nice as well.

 

[Brooothru]

I haven't done this for quite a while.

1. I now use a 400 micron brew in a bag bag. Once I started using that it didn't scorch. But I sure scorched the hell out of my fast batch pre-400 micron bag
2. I did several batches using the spent grains + 6-row. Came out fine but not a superlative beer. I should try an AK recipe with spent grains, 6-row, bit of corn, English hops and see how that goes

I keep checking in on this thread and prolly will take a few runs again in the summer. A saison might be nice as well.

That might be a good method to try. I've got several Swiss voile bags left over from when I used to do BIAB. I could put a BIAB bag in the all-in-one, cold soak the grain for 8 hours, pull the bag, heat to 155-160F for an hour, then boil. Save the grains for a second mash with a few specialty grains. Done deal.

My only concern would be the center post in my all-in-one (Braumeister). It uses a 'malt pipe' that inserts over a central rod with filter screens at the top and bottom. I'm trying to figure some way to drape the bag over the center post, possibly with the bag fully contained within the malt pipe with filter plates at the top and bottom of the malt pipe. With recirculation I might be able to cut down the cold mash to an hour or two, with it continuously 'vorlaufing' for a clear wort. Might be a winner!

 

[BrewnWKopperKat]

(Bump. As I was scanning the 'interwebs' over the last couple of weeks, I noticed a couple of brewing mentioning home brewing very low ABV beer using 'cold mash' techniques.).

 

[BrewnWKopperKat]

This web site (UltraLow Brewing Techniques) was referenced in a different topic. Adding it here so I can find it again in the future.

 

[Sotko]

Thank you to everyone who put in the work t test and share all of this! I’ve been looking for a super low ABV option for a few reasons and came across this. Is anyone still trying this?

Based on the notes in this thread, I decided to try a petite porter since I’m the hope that the darker specialty malts might mask or maybe even be complimented by the grainy results being reported. I also made some small adjustments to the process: I cold mashed at room temp for about 5 hours instead of overnight, reduced the amount of base malt a little relative to the original recipe and added some crystal.

I based my recipe on this one by TheMadKing. For a 2.5 gal batch:
3# MO
1# Munich II
1# brown malt
0.25# medium crystal
0.25# biscuit
0.5# chocolate
0.25# black

0.25 oz fuggle @30
0.75 oz fuggle @5

Fermented with wlp002

My experience was similar to others - super turbid but cleared with 30 minutes at 152. I didn’t have any scorching issues.

Came out with OG of 1.017 and an FG of 1.012. Even after bottle carbing it will finish just under 1%. I’m waiting for bottle carbing to finish (I’ll upgrade to kegging one of these days). I’ll update after it’s done, but samples tasted… like porter. A little grainy but mostly in a not unpleasant almost complimentary way.

*edit: corrected black malt in grain bill and broken link

 

[Sotko]

I just tried one of the low abv porters and it tastes like a porter. It’s a little thinner than I would like a porter, but it’s not watery. My goal wasn’t to fool anyone, but this could probably pass for a regular porter. I might taste test it against some commercial porters to see if friends can pick it out.

I don’t really get any graininess. Not sure if the 5 hour vs 12 hour mash or the lower ratio of base malt to specialty malts had an impact (this brew wasn’t really set up to isolate variables), but definitely having a style with a lot of dark specialty malts seems to work really well with this method (a handful of black malt will hide a lot). I’ll definitely brew this again, probably with some adjuncts to increase mouthfeel.

 

[brewbama]

I have my first NEM mash, a Vienna Lager, in the fridge right now for a tomorrow AM brewday. I wanted a simple beer to judge the technique.

I milled 7# base grains, added my salts, Brewtan B, and acid, mashed in with room temp deaerated RO water, and placed the primary mash tun (a repurposed bucket fermenter) in a 32°F fridge for an overnight rest.

Tomorrow AM I will head back upstairs to the brewery, hoist the grain bag out of the primary and let it drain for an hour allowing the residual starches to settle below the spigot. Then, I’ll drain the initial mash wort into the secondary MLT for the ‘high mash’ (leaving the settled starches behind in the primary mash tun). I may transfer to the kettle, heat it, then transfer to the secondary MLT. The MLT heats via HERMS so the kettle would be faster but I am not sure the speed of direct heat is my friend in this situation. The slower indirect heat of the HERMS may be better in this situation. Decisions, decisions.

Either way, after the wort is at my target (172°F) I’ll add the .5# dark grains to the grain bag, place the bag in the secondary MLT to serve as a filter, and start the recirculation for the vorlauf/hot steep/‘high mash’.

I understand removing this settled residual starch is vital to success so I’ll vorlauf until clear. I am planning at least 30 min but it could be longer.

I’ll then xfer the — hopefully — clear, very low SG, but flavorful wort to the brew kettle and continue a routine brewday.

I’ll take some pH readings along the way. I have no idea if pH even matters in a mash that I don’t want enzymes to convert starch to sugars but we’ll see what they are anyway.

My goal is a full flavor, full mouthfeel, low carb beer. I don’t want a thin, watered down beer. I‘m sure this first run will need some future adjustments and I’m OK with that. We’ll see.

ref:

 

[BrewnWKopperKat]

but I am not sure the speed of direct heat is my friend in this situation

As I understand it, heating the wort from room temp to a boil often results in a ~ 1% beer beer; while a rest at ~ 152* F results in a ~ 3% beer. When I used this technique I included the rest. Obviously the results will depend on the amount of sugars from the cold extraction step.

 

[Brooothru]

I have my first NEM mash, a Vienna Lager, in the fridge right now for a tomorrow AM brewday. I wanted a simple beer to judge the technique.

I milled 7# base grains, added my salts, Brewtan B, and acid, mashed in with room temp deaerated RO water, and placed the primary mash tun (a repurposed bucket fermenter) in a 32°F fridge for an overnight rest.

Tomorrow AM I will head back upstairs to the brewery, hoist the grain bag out of the primary and let it drain for an hour allowing the residual starches to settle below the spigot. Then, I’ll drain the initial mash wort into the secondary MLT for the ‘high mash’ (leaving the settled starches behind in the primary mash tun). I may transfer to the kettle, heat it, then transfer to the secondary MLT. The MLT heats via HERMS so the kettle would be faster but I am not sure the speed of direct heat is my friend in this situation. The slower indirect heat of the HERMS may be better in this situation. Decisions, decisions.

Either way, after the wort is at my target (172°F) I’ll add the .5# dark grains to the grain bag, place the bag in the secondary MLT to serve as a filter, and start the recirculation for the vorlauf/hot steep/‘high mash’.

I understand removing this settled residual starch is vital to success so I’ll vorlauf until clear. I am planning at least 30 min but it could be longer.

I’ll then xfer the — hopefully — clear, very low SG, but flavorful wort to the brew kettle and continue a routine brewday.

I’ll take some pH readings along the way. I have no idea if pH even matters in a mash that I don’t want enzymes to convert starch to sugars but we’ll see what they are anyway.

My goal is a full flavor, full mouthfeel, low carb beer. I don’t want a thin, watered down beer. I‘m sure this first run will need some future adjustments and I’m OK with that. We’ll see.

ref:

Really anxious to hearing about your successes/shortcomings with this process. I’ve been wanting to try it myself. I do question the temperature however (32F). Thought the target was more like low to mid 40s F.

My hangup so far is mashing ‘low O2’ since I’m thinking I’d cold mash BIAB in a Brew Bucket, suspend the bag to drain, then let the starches settle to the bottom before the starch conversion mash. Still trying to sort out how I’ll work the process, given my gear and my focus on LoDO.