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Old 08-13-2007, 01:10 AM   #1
Turkeyfoot Jr.
 
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May 2007
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So I decided to try my first double brew today. In hindsight, given that these were just my 2nd and 3rd PMs EVER perhaps I was being a little too ambitious. The first one is sitting in the fermenter now and the second is mashing so it's going to be a long evening and an even longer day tomorrow at work.

Anyway, to the point of my post. My target OG for the first brew was 1.055. It was a rye ale and the recipe's below. My actual OG was a dismal 1.041. Here's what I think went wrong. My strike water was about 160F and probably should have been more like 162 because after dough-in the temp of the grist was 148F. I decided not to do anything with it at that time and 20 minutes later when I opend my cooler to stir I was shocked to find the temp had dropped to 144F. I quickly heated about 2Q of water to 178F and through it in. This raised the temp to 150F and I left the lid on for the remainder of the mash which was 30 minutes by this point. Would the temp being too low for half the mash have caused a terribly low efficiency which in turn caused a very low OG?

The recipe:

3.5lb. Wheat Malt
2.25lb. Rye Malt
0.25lb. Carafa
2.5lb. Amber DME
0.5lb. Lite DME
1.5oz. Hallertau
Wyeast 3068

As I said above, the grains were mashed for 60 minutes. THe DME was added at the last 15 minutes of the boil.

Let me know if there are any other details you guys need.
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Old 08-13-2007, 02:33 AM   #2
Thalon
 
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As I just learned from my first AG batch, 144-150 is a good range for the beta amylase but too low for the alpha amylase to work. If you have some mash time in the beta range, you should have some time in the alpha range as well, 150-158. 150-152 would've been ideal to hold the entire 60 min, but if you already had half the time lower than that I would say hold a temp more in the alpha range for the other half. Palmer's How To Brew is a great resource too: http://howtobrew.com/section3/chapter14-5.html

Was the wheat malt unmodified or partially modified? If so, it would require a protein rest around 120-122 before the main mash. That could be another source of low efficiency.

 
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Old 08-13-2007, 02:51 AM   #3
Turkeyfoot Jr.
 
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I will have to check with my LHBS on the wheat, not sure if it's unmodified or not.

Sounds like the temp could have been my biggest problem though. 30 minutes at 144 followed by 30 minutes at 150 means I really didn't have a good amount of time in the alpha phase. Oh well, I'm sure it will still turn out good just low on the alcohol content.
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Old 08-13-2007, 04:45 PM   #4
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You need some 2 row malt to convert the starches from the wheat and other malts you used. Wheat malt by itself doesn't have sufficient enzymatic activity to do it itself. You can get away with about a 60:40 ratio - ie you need at least 40% of a well modified 2 row to convert 60% wheat + other adjuncts in your mash.

 
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