I did not see a thread on this yet, but Bill Covaleski gave out the Storm King recipe on the 6/17/2013 Sunday Session episode. Here are my notes: Malt (1.087 OG) 77% 2 row Pils 12% 2 row Vienna 5% roasted barley 5% Carafa III 1% CaraAroma Two step infusion mash: 149F for 45 mins, 161.6F for 30 mins. Hops (85 IBU) Cascade - 50% of hop bill. 2/3 at 15 mins, rest split between 5 min addition and hopback. Centennial - 25% of hop bill. Additions at 60, 30 and 15 minutes. Chinook - 25% of hop bill. 1/3 at 5 min, rest in hopback. Knock out at 57-59F, pitch 18-23 million cells/ml of American Ale yeast. Cap fermentation temp at 62F.
No explanation was given in the interview but my guess is to compensate for the lower than usual temperature. Bill gave that temp as both 72C and 161F so I don't think it was a misspeak. Fermentation temp was a bit of a surprise too. I should have noted that Victory uses a proprietary ale strain for their beer, but one known for clean flavor. Has anyone ever tried WLP001/WY1056 at these temps?
I believe the question was 'Why so long at a low (for a mashout) temp?' It's really more like a second sacch rest.
I'm not finding a good chart on that. It seems like there's still activity at 161 or 162F. Mash out is still 160, and I didn't miss a meeting, right?
I target 168 for my mashouts. The higher the temp, the faster the enzymes are denatured. 168-170 is good because it denatures relatively quickly, doesn't get you into the prime tannin stripping zone, and it's above the optimal ranges of both enzyme types.
One also needs to know that Beta denatures at 158F, Alpha at 178F. The Alpha still is working at mash out.
Deja Vu all over again. --- Notes from a talk by Dr. Michael Lewis "GETTING THE MOST FROM AMERICAN MALT" Liberty Malt Supply's Homebrew U March 27, 1993 "For American pale malt, optimum fermentability is obtained at temperatures of 55^ - 60^ C. (131^ - 140^ F.). At these temperatures, the beta amylase enzymes produce maltose most efficiently. This happens early in the mash in a fairly short time, approximately 20 minutes. The alpha amylase enzymes, on the other hand, produce the dextrins that give us the total extract we desire at temperatures between 70^ - 75^ C. (158^ - 167^ F.). It is possible to mash American pale malt with a single temperature infusion. While this can be a reasonable compromise approach, it inevitably results in a loss of either fermentability or extract, since the temperature is not optimum for either. The best plan for mashing American pale malt is a "temperature program" in order to obtain the optimum balance of extract and fermentability. A sample two temperature program, utilizing the popular "camp cooler" mashing method, would be something like this: 1. Stir in enough hot water at around 70^ C. (approximately 158^ - 160^ F.) to make a thick mash, so the temperature settles in between 55^ - 60^ C. (131^ F. - 140^ F.) Initial mash temperatures as low as 50^ C. (122^ F.) are acceptable. Hold for 20 - 30 minutes at this temperature. 2. After 20 - 30 minutes, add enough hot water just off the boil to raise the temperature to 70^ - 75^ C. (158^ - 167^ F.) for the remainder of the mash period. What many American home brewers don't realize is just how low a temperature American pale malt needs for optimum fermentability and how high a temperature it needs for optimum extract. Dextrins do not, as far as experiments disclose, contribute "body" as is frequently stated, but rather contribute a desirable aftertaste. The so-called "protein rest" usually advocated for American pale malt does not seem to have any real basis. Everything that needs to happen in the mash will happen with a proper temperature program that addresses fermentability and extract. [Dr. Lewis's comment was actually that the protein rest was "bullshit"!]"
Given this, what is the difference between a rest at 161F vs 168? If I am understanding correctly won't alpha-amylase be active and beta denatured either way? Thanks!
I had a typo, the Alpha denatures at 176f. Peak Alpha is in the 162F range IIRC. If you do a step at 161 - 162f, sure the Beta is denatured. Mash out at 168 is also to help the sugars flow easier. A common step mash for me is 144-145F, 156-158F, mash out at 168-170F.
There is something I am still not getting - if alpha amylase is active at mash out temps, why bother with the rest at 162? In searching for an answer I found some literature describing a "Hochkurz mash", which seems to be what this recipe employs. However, Kai Troester's description of the dextrinization step of a Hochkurz mash indicates that its purpose is to ensure full starch conversion, and the acceptable temp range for that step is 158F-172F, so it seems like a normal mash-out would do the same thing. (Kai goes on to say that extending this rest after conversion is complete provides head retention and mouthfeel benefits. Presumably an extended 168F rest would do that too, since it falls within the specified temperature range.)
The peak rate is at about 162F. Kai has an informative chart in his "How pH Affects Brewing" section.
The second time you said peak I got it. I guess pros would care about stuff like minimizing time per step.
If anybody is looking for an Imperial Stout recipe, I brewed this one on August 31 and am more than pleased with the result. Some notables are the recommended pitch rate, which is significantly higher than Mr. Malty's suggestion for the same gravity and batch size. Also, I think this might be my first homebrewing loss. This recipe took a full pound of hops, 25 pounds of grain and two packages of yeast. In the end it would have been cheaper to buy three cases of the real thing. Still, it was a good learning experience and I already bought 2013 hops for the rebrew. Finally, I will probably skip the hopback next time and just do a regular hop stand to limit losses. Recipe Specifics ---------------- Pre-Boil Wort Size: 10.50 Gal Pre-Boil Gravity: 1.066 Plato: 16.19 Batch Size (Gal): 8.00 Wort Size (Gal): 8.00 Total Grain (Lbs): 25.65 Anticipated OG: 1.087 Plato: 20.89 Anticipated SRM: 47.5 Anticipated IBU: 85.9 Brewhouse Efficiency: 73 % Wort Boil Time: 120 Minutes Evaporation Rate: 1.25 Gallons Per Hour Actual OG: 1.087 Plato: 20.90 Actual FG: 1.019 Plato: 4.83 Alc by Weight: 7.02 by Volume: 9.05 From Measured Gravities. Grain/Extract/Sugar % Amount Name Origin Potential SRM ----------------------------------------------------------------------------- 72.5 18.60 lbs. Pilsener Germany 1.038 2 11.3 2.90 lbs. Vienna Malt Germany 1.037 3 4.7 1.20 lbs. Roasted Barley America 1.028 450 4.7 1.20 lbs. Carafa III Germany 1.030 525 1.0 0.25 lbs. CaraAroma Germany 1.033 130 5.8 1.50 lbs. Rice Hulls 1.000 0 Hops Amount Name Form Alpha IBU Boil Time ----------------------------------------------------------------------------- 1.60 oz. Centennial Whole 8.90 33.6 60 min. 1.20 oz. Centennial Whole 8.90 12.9 30 min. 1.20 oz. Centennial Whole 8.90 6.7 15 min. 5.40 oz. Cascade Whole 6.81 23.2 15 min. 1.30 oz. Cascade Whole 6.81 3.5 5 min. 1.30 oz. Chinook Whole 11.83 6.1 5 min. 1.30 oz. Cascade Whole 6.81 0.0 0 min. 2.70 oz. Chinook Whole 11.83 0.0 0 min. Yeast 2 x Wyeast 1056 Fermentation Notes ------------------ Shooting for two 3-gallon batches. Prepping 1.25L starters for each to reach 18-23M/ml pitch rate. Kegged on 9/15/2013. SG was 1.024 (1.024 at 64F) Hydro sample tasted good, but no noticeable hop aroma. Plenty of hop flavor though, but still a little malt dominant. Keeping temp in mid-high 50s and CO2 under 10 psi for a TBD conditioning period. Tasting Notes ------------- 10/15/2013 - definitely tastes like Storm King, but aroma is still lacking. 10/19/2013 - FG stable. Moved to serving fridge and set regulator for 2 volumes CO2. Problem Notes ------------- Shooting for mash pH of 5.6 but got 5.24. Next time add 10-20g of baking soda in addition to current water recipe. Estimated 78% efficiency but got 73%. Boiled for an extra 30 mins to compensate. Lost about 1/2 gallon of wort as a result. Fresher hops would have helped too. Notes ----- AA values include losses based on August 2013 brew date from current hop inventory (most from 2011). Changed Centennial additions from three equal amounts at 60, 30 and 15 to hit IBU target.
