Tuesday, May 22, 2007

Brewing a wheat doppelbock

Ah, spring. On May 21st, 2007, after a brief hiatus from brewing following Anna's birth in February, I finally managed to stay up late and brew what will hopefully be my tastiest brew yet. It is a clone of Aventinus wheat doppelbock, brewed by Private Weissbierbrauerei G. Schneider & Sohn, described by the brewery as, "Dark-ruby, almost black-colored and streaked with fine top-fermenting yeast, this beer has a compact and persistent head. This is a very intense wheat doppelbock with a complex spicy chocolate-like aroma with a hint of banana and raisins. On the palate, you experience a soft touch and on the tongue it is very rich and complex, though fresh with a hint of caramel. It finishes in a rich soft and lightly bitter impression." Sounds good to me.

Brewing started after dinner, about 7:30pm, by heating up 5 gallons of water to 163 deg F. This was not as easy as it sounds because I have suspected that our thermometers are not reading accurately, so after a couple of efforts to calibrate one of them, I got the water to temperature and added it to the crushed grains, all 18.5 lbs of them. The grain bill was:

10 lbs American White Wheat Malt

6 lbs American Pale 2-row Malt

1.5 lbs American Munich Malt

9 oz. 90 deg Lov. Crystal Malt

1 oz. Chocolate Malt

4 oz. Caramunich Malt

I increased the amount of malt the recipe called for by 2.5 lbs to make sure I didn't fall short of my predicted specific gravity (a measure of how much sugar gets dissolved into the sweet wort). I'm glad I did because I was right on target. I'm still not sure why my beers have been coming out with lower gravities than expected. I was thinking the lower mashing efficiencies were caused by inaccurate temperature readings, but that may not be it, or may only be a part of it.

Mashing takes about 90 minutes. Then sparging (straining the spent grains out of the now sweet liquid) took another hour, then getting three kettles boiling took me another hour. The picture to the left is the bucket of spent grains.

I let the wort boil for close to an hour before putting in 1 oz. of German Halertauer hop pellets for bittering. Once the bittering hops were in, the wort boiled for another hour, with an addition of 1/2 oz. more of the same hops, this time for aroma. I skipped the addition of Irish moss (a clearing agent) with the aroma hops, but it shouldn't matter since I boiled the wort for an hour prior to adding the hops.

The next step is cooling the beer. You can see the tubing in the big stock pot on the right of the range top that is connected to a copper coil. One of the tubes has a connection that fits the threads on a faucet, and allows water (preferably cold if you want the boiled wort to cool) to be circulated through the copper and draw the heat out of the wort and then carries the now hot water through the exit tube and into the sink. That cloudy stuff in the pot is the "cold break" or proteins that precipitate out of the wort when it is cooled. This is beneficial to the clarity of the final beer as well as improving the taste.

The penultimate step pertaining to brewing is the pitching of the yeast into the cooled wort. For this beer I had a 1 quart starter made from the yeast packet (containing liquid yeast and nutrients). The yeast called for in the recipe is Wyeast 3333 German Wheat. Wheat yeasts typically produce a combination of estery flavors (banana or other fruit-like tastes) and phenolic flavors (clove or other spicy, sometimes medicinal).
The yeast is contained in a plastic pouch inside the foil packet. The pouch is smacked to break the pouch and release the yeast into a nutrient rich environment so it can start reproducing and build up a large enough "colony" to do the work of fermenting the wort. Although it is possible to pitch the yeast/nutrient liquid directly into a 5 gallon batch of wort, it is better to create a 1 quart starter by boiling 1 quart of water for 10 minutes with enough dry malt extract to make a wort with a specific gravity (s.g.) of 1.045. This yeast starter is then added the wort in the fermentation pail, which is then covered with a tight fitting lid with an airlock to let the CO2 gas escape during fermentation, but keep oxygen and contaminants out, because these things can ruin the beer.

The final step on brewing day (or brewing night) is to clean up the mess--which means wipe up the spilled wort off the floor, off the stove, clean the cooking pots, wort chiller, sparging pail, miscellaneous plastic tubing, and put it all away. I usually get most of this done, but occasionally wait until morning to put the clean pots and pails away.
The Aventinus clone has a starting gravity of 1.075, which will result in a beer of approximately 7.7% alcohol by volume. As of late, my beers have been attenuating more than the recipes I follow predicts it to be, which means they have a little more alcohol (assuming they started at the predicted s.g.), and are a little less full bodied than what they should be. Oh well, they usually still taste pretty darn good. I bottled this beer on July 1st and used 1-1/4 cups of wheat dry malt extract dissolved in two cups of water to prime the bottles so the final beer will be carbonated. The final gravity was 1.010, which was 0.005 below the anticipated final gravity.

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