Opinions re cold extract?

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mashdar

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Hi all! I was hoping for some input regarding cold extract process/recipes. I have read a bunch of articles which sound very promising, but forum posts with tasting notes generally don't sound too great.

Things I'm thinking about:
1. General thoughts? Pros/cons vs partigyle/high temp mash/small grain bill?
2. Extract temperature, time, and recirc. I'd much rather do a 2 hour recirc at 65F than figure out a way to do a 40F soak overnight. Articles are very wishy washy regarding process requirements here.
3. Should there be a starch precip rest before heating? Seems like that could help a lot.
4. Mash oatmeal, crystals, etc at normal mash temp rest? Seems like this would help round out the character while using cold base extract for amy and background character. Oatmeal for some B glucans, which aparently are not very soluable in cold extract. Might need some serious rice hulls. Or maybe a thick 180F extract added to base cold extract for amy rest. (Thinking out loud.)

Personally I'm looking for 2-3% abv but don't care about calories. This seems like a neat tool to add to the arsenal, but I'm debating where to start.
 
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Hi!

1- and 3-
Low Enzymatic/Cold Mash/Low alcohol beer
Some brewers had problems with particles, when didn't use Biab bags. So a starch precip rest should help.
2-Cold Extraction of Malt Components and Their Use in Brewing Applications - Brewing With Briess
The temp, just has to be below first rest temp. I think it's acid rest, at 100F: https://grainfather.com/step-mashing-what-is-it-and-why-do-it-2/
But you have to do a normal mash rest, after separate wort from grains.
According to briess guys, 1 hour with recirculation should be enough.

4- crystal has few to none starch, should be used in the cold mash. Oatmeal, I don't know. I would suggest in the hot mash.


If you don't care too much about calories, a higher hot mash should be fine.
Best Practices – Low alcohol beer | Lallemand Brewing

Hop that helps, if you try something like this, please share with us. I'm looking into low abv beers too!
 
Hi!

1- and 3-
Low Enzymatic/Cold Mash/Low alcohol beer
Some brewers had problems with particles, when didn't use Biab bags. So a starch precip rest should help.
2-Cold Extraction of Malt Components and Their Use in Brewing Applications - Brewing With Briess
The temp, just has to be below first rest temp. I think it's acid rest, at 100F: https://grainfather.com/step-mashing-what-is-it-and-why-do-it-2/
But you have to do a normal mash rest, after separate wort from grains.
According to briess guys, 1 hour with recirculation should be enough.

4- crystal has few to none starch, should be used in the cold mash. Oatmeal, I don't know. I would suggest in the hot mash.


If you don't care too much about calories, a higher hot mash should be fine.
Best Practices – Low alcohol beer | Lallemand Brewing

Hop that helps, if you try something like this, please share with us. I'm looking into low abv beers too!
My thought with the crystal at normal mash temps was that there's no fermentables to worry about. (edit: looks like I'm wrong, and crystal is fairly fermentable? but if preconverted, soak temperature probably doesn't matter) It can't hurt in case there are temperature-sensitive flavor extracts to be had?

My impression re low temp base malt extract is that amy and flavor compounds are still highly soluble, but the starch is quite insoluble. B gucans are apparently also pretty unavailble at low extract temps, hence the oatmeal idea. (Several articles recommend oats or rye for this reason.)

My biggest concern with high dextrin (high mash temp) beer is possible gut flora interactions. I don't want to make my guests gassy!

I'll take a stab and report back in a few months. I do long primaries and bottle conditioning, so very slow turn around.
 
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My thought with the crystal at normal mash temps was that there's no fermentables to worry about. (edit: looks like I'm wrong, and crystal is fairly fermentable? but if preconverted, soak temperature probably doesn't matter) It can't hurt in case there are temperature-sensitive flavor extracts to be had
Yes, they've fermentables, but they're already converted. So all should go with cold mash. A hot mash doesn't hurt in this case and can extract more flavour, I guess.

My impression re low temp base malt extract is that amy and flavor compounds are still highly soluble, but the starch is quite insoluble. B gucans are apparently also pretty unavailble at low extract temps, hence the oatmeal idea. (Several articles recommend oats or rye for this reason.)

Yes, I read that too. Makes sense.


My biggest concern with high dextrin (high mash temp) beer is possible gut flora interactions. I don't want to make my guests gassy!

Oh, that's a problem! I like dry beers, they are more "digestible" (quoting someone else). Beers with too much carbs could be cloying.

I will brew one too, but at end of this year, probably.

Cheers!
 
I finally got around to brewing last night. A starch precipitation rest of ~1 hour certainly dropped some starchy sludge out. Definitely worth it.

While my intent was to brew a stout, I decided to do a brown instead, using the same recipe as my previous batch, with added oats.

Steps:
  • 8lbs MO cold extracted at 54F for 2 hours with ~0.5gpm recirc.
  • Then added boiling water to full volume (7gal preboil), which resulted in 150F. Heated to 158F.
  • 1lb quick oats, 4 oz each Special B, Chocolate, Roasted Barley mashed in hop spider with recirc into spider, 30 minutes.
  • normal boil etc, 1500W element took a while to get to boil.
Final volume 5.9gal, OG 1.014. Not super low, but about what I wanted. Curious to see where FG goes.

Should be interesting to compare directly with the 4.7% ABV version.
 
Bottled last night. Wow.

FG was 1.010, pre-priming ABV ~0.59%. This is a case where 0.2% ABV from priming is quite significant. Attenuation seems low (S-04), but I'm in uncharted territory.

Initial taste was fine, although it tastes a little "NA". The toasty grain flavors are more clear than I'm used to. I wonder if something that usually gets CO2 scrubbed remains. The mouthfeel for uncarbed beer was actually pretty good.

I'm wondering if
a) I jumped the gun on packaging? Not sure how it could stall after 0.004 drop, and tasted pretty dry. We'll see what they do in bottle.
b) Did I under-do the cold soak at 2 hours and missed out on some amy? Maybe I didn't get good conversion of oats/roasted grains.
c) I might move more grain to the propper mash next time to hit ~1.5%. Or purposefully add some starch back after rest?
 
After 2 weeks in bottle, a comparison with normal ABV version of same recipe (sans oats). TB = Tiny Brown. FB = Fat Brown.

(edit:
TB was 1.014OG to 1.010FG. That's just under 0.6% ABV. Bottle priming added ~0.2%, for final ABV 0.75%-0.80%. TB had 1 week primary, 2 weeks in bottle at 60F.
FB was 1.048OG to 1.012FG, 4.7% ABV, plus 0.2% for bottle priming. FB had 2 week primary, 1 month in bottle at 60F, 1 month in refrigerator.
)

Appearance: TB dropped completely clear before I even bottled it at 1 week at 65F ambient. Nice ruby red. Very similar to its big brother. Almost identical.

Head: Both poured with little head. Lightly carbed. A rough pour of TB yields little head. Likely due to oats.

Aroma: TB oddly missing vs FB. Faint but similar.

Mouthfeel: TB mouthfeel is fine. Roughly normal for a 5% beer. Very similar to FB.

Flavor: TB is very dry, but not astringent. Grain flavors mellowed & blended nicely in bottle. It is dry enough it would make a nice dry stout or dry pale. For a mild, it needs some more crystal or even lactose. I suspect the alcohol sweetness is what's missing, plus whatever real residual is hidden by alcohol gravity during hydrometer reading.

Flavor comp: TB is missing alcohol sweet, bitter, and nose vs FB. Missing some signifcant dark cherry flavor I associate with dark liquor. My brain wants to call the flavor "ruby". Not sure if it's a yeast product, or some interaction of yeast with dark grain. It's a flavor I don't associate with paler beer.
 
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I just realized the missing flavor in the Tiny Brown vs the Fat Brown is the flavor I dislike in Glenlivet 12. I think wild turkey may have the same flavor, but I had that once 15-20 years ago. It's a tart cherry flavor.
 
Minor update: I've been reading a bit more about low/no alcohol brewing, and one article pointed out the higher likelihood of spoilage. A little more digging, and I realized that my limited fermentation may not have dropped the beer pH out of the botulism danger zone (below 4.6).

I've managed thus far without a pH meter, but safety is where I draw the line -- I'll pick one up and update with a finished pH of the unadjusted, bottle carb'd beer.

I haven't died yet, but caveat braciator and safety first.
 
Wowzuhs.

Bottle carb'd beer: pH = 4.4
Bottle carb'd beer, decarbonated: pH = 4.7
Beer prior to bottling: ?? Probably closer to pH = 5.0 (The bottle conditioning increased alcohol content by 30-50%, so the yeast action was significant.)

What does this mean? It means it is conceivable to grow botulism in super low ABV beer. If you are going this route, I would strongly recommend you include pH testing and adjustments of the wort pre-pitch. Since the (extremely deadly) toxin is quite stable even after the pH goes too low for the bacteria to grow, you really want the pH of the beer below 4.6 within a few days of pitching, which I clearly did not achieve here.

I've got some malic acid and malic/tartaric/citric blend sitting around from non-beer activities. I see a lot of people adjust mash pH with lactic acid. If anyone has thoughts about ideal wort pH adjustment, I'd love the input.

(There is some indication that hops may be effective and preventing botulinum growth, but I have not found anything conclusive. Not worth risking death on it.)

Edit: for comparison, I tested pH of the following (decarbonated). I'll add more as I measure.
4.7% ABV Mild: ph = 4.1
3.5% ABV Pale: pH = 4.4
 
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4.9% dry stout: pH=4.3
3.0% dry stout: pH=4.1

(Most of these beers are s-04 unless noted otherwise. 3.0% dry stout fermented very warm (80F), which might have influenced pH? I'll keep some more notes going forward.)
 
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