#31 Dunkelweizen

Eureka, today about a recipe I designed myself and brewed three times already. The recipe below is for a relatively straight forward Dunkelweizen (dark wheat beer, BJCP category 15B). I like dark beers in general and decided to create a darker version of a wheat beer. No further introduction, let’s go through the recipe:

Recipe:	Dunkelweizen
Numbers:	Volume [L]	20 (5.3 gal)
	Original gravity	14°P (1.056)
	Terminal gravity	5.4°P (1.021)
	Color	Around 30 EBC
	IBU	12 IBU
	ABV	4.7%
Grains:	Munich malt (14.5 EBC)	1.0 kg
	Wheat malt dark (16 EBC)	2.6 kg
	Pilsner malt (4 EBC)	1.0 kg
	Cara Wheat (115 EBC)	0.3 kg
	Carafa Typ 1 (900 EBC)	0.06 kg
	Acidified malt (4 EBC)	0.15 kg
Hops:	Hallertauer (8% AA)	12 g and boil for 90 min
Yeast:	Wyeast’s	#3068 Weihenstephan
Water:	Burgdorf	Mash: 3.4 L (0.66 gal), sparge: 20 L (5.3 gal) @78°C (172°F)
Rest:		Mash in @47°C (117°F) 20 min @45°C (113°F) add acidified malt, 15 min @53°C (127°F) 30 min @63°C (145°F) 40 min @72°C (162°F) 10 min @ 78°C (172°F)
Boil:		Total 90 min
Fermentation:	Primary	7 days @20°C (68°F) in plastic fermenter
	Secondary	None
Maturation:	Carbonation (CO2 vol)	3.5 with fresh wort
	Maturation time	3-4 weeks

05/13/11: Brew day number 31. All went according to the protocol above. Crush all the grains as mentioned in the recipe but crush the acidified malt separately. Then mash in at 45°C (113°F) but not the acidified malt. This malt is added after the 20 min rest at 45°C (113°F). The reason for this is to prevent a lower mash pH during the ferulic acid rest at 45°C. For further information have a look at a previous post of mine #48 Dunkler Nachthimmel.

Fig 1: Dunkelweizen mash

Then do the next rests at the mentioned temperatures, then sparge and boil the wort for 90 min with the hop addition. This beer is not about hops and therefore only a small amount of hops is added.

Fig 2: Collecting the Dunkelweizen wort

After the boil fill 10% of the wort’s volume into clean, disinfected glass bottles. In my case 2 L (0.53 gal). This fresh wort is needed at bottling to get the right amount of carbonation. Store the fresh wort in a refrigerator. Cool down the rest of the wort to pitching temperature of about 20°C (68°F) and pitch healthy Wyeast’s #3068 Weihenstephan yeast or any other wheat yeast you want.

I bottled the beer directly after a primary fermentation of seven days. I used the fresh wort to get the right amount of carbonation (3.5 vol of carbon dioxide). And there are enough yeast cells in the fresh beer. So no need to add fresh yeast at bottling. Please check whether your bottles can handle such high carbonation levels! Otherwise, you will have a lot of bottle bombs…

I then leave the bottles at fermentation temperature for another week or two and then store the bottles in a refrigerator. The beer is ready to drink within three weeks after bottling.

Tasting:

Aroma: Lots of banana, some caramel notes and the typical wheat beer character. No sulphur. Very nice aroma. Makes you thirsty!

Appearance: Brown color, the yeast in suspension makes it cloudy. Three finger tan, frothy head with a lot of bubble rising to the top.

Flavor: Pretty much the same notes I could detect in the aroma. Banana in the front, some caramel character, hints of spicy, phenolic notes.

Mouthfeel: Light-medium body, lively carbonation. Finishes with a malty and fruity aftertaste. The light-medium body makes it a bit heavier than a normal, pale wheat beer. However, the higher body does not make it less enjoyable. It is still a very easy to drink beer.

Overall Impression: I really like this beer. It has all the characteristic aroma, flavor profile you would expect from a wheat beer. Plus some additional character from the darker malts such as caramel. I am pretty satisfied with this recipe and would not change anything.

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#48 Dunkler Nachthimmel

Eureka, its time for another recipe. Today’s recipe is called Dunkler Nachthimmel (dark night sky) and belongs into the category of Dunkelweizen (dark wheat beer). And this brew is my very first open fermented beer ever. More about that later on. I brewed this recipe before (#31 Dunkelweizen) but used a closed fermenter.

I really like the Brewing TV channel and their videos. So, one day I watched episode number 4 called open fermentation. You should definitely have a look at this episode if you have never used the open fermentation technique before. What I took from this episode is the fact that an open fermentation should lead to a more banana pronounced wheat beer than using the standard (for homebrewers) closed fermentation technique. And since I really like the banana character in a wheat beer, I decided to give this technique a go. It has to be mentioned that a lot of German wheat beer brewers use the open fermentation technique every day. Therefore nothing special in the wheat beer process.

Some further information about the recipe. One special rest is included below, the so called “Ferulasäure Rast”. Ferulasäure, in English ferulic acid, is the precursor for 4-vinyl guaiacol which has a clove aromatic aroma. The conversion from ferulic acid to 4-vinyl guaiacol is then made by the yeast cells during fermentation. One way to improve the clove aroma of a wheat beer is to include a Ferulasäure rest to increase the amount of ferulic acid in the wort. And this rest is done at 45°C (113°F). Another important thing for the Ferulasäure rest is the mash pH. The release of the ferulic acid from the grains decreases at lower pH values. To prevent a lower pH level for this rest, the acidified malt is therefore added after the Ferulasäure rest. Enough of water science and ferulic acid, lets go through the recipe.

Recipe:	Dunkler Nachthimmer
Numbers:	Volume [L]	10 (2.6 gal)
	Original gravity	12.8°P (calculated 13.8°P)
	Terminal gravity	5.2°P
	Color	Around 30 EBC
	IBU	11 IBU
	ABV	4.2 %
Grains:	Munich (14.5 EBC)	0.5 kg
	Wheat malt (16 EBC)	1.4 kg
	Pilsner malt (4 EBC)	0.5 kg
	Cara Wheat (900 EBC)	0.15 kg
	Carafa 1 (900 EBC)	0.03 kg
	Acidified malt (4 EBC)	0.075 kg (added after the rest @ 45°C (113°F)
Hops:	Hallertauer (4.2% AA)	11.4 g and boil for 60 min
Yeast:		#1084 Irish Stout
Water:	Burgdorf	Mash: 7.5 L (2 gal), sparge: 10 L (2.6 gal) @78°C (172°F)
Rest:		Mash in @47°C (117°F), 20 min @ 45°C (113°F), 15 min @ 53°C (127°F), 30 min @ 63°C (145°F), 10 min @ 78°C (172°F)
Boil:		Total 60 min
Fermentation:	Primary	7 days @ 20°C (68°F) in an open plastic fermenter
	Secondary	7 days @ 20°C (68°F) in bottles
Maturation:	Carbonation (CO2 vol)	3.5 (carbonated with table sugar)
	Maturation time	3 weeks

03/24/12: Brew day. All went according to the protocol. Iodine test was negative and the sparging went very well (for a what beer). After boiling the wort with the Hallertauer hops for 60 min, the wort was cooled down to 20°C (68°F) and added a yeast suspension of Wyeast’s #3068 Weihenstephan yeast. The Weihenstephan yeast originates from my yeast library. I banked the yeast in June 2010, and the yeast is still active after nearly two years in the isotonic sodium chloride solution. So I transferred 5 mL of the isotonic NaCl solution in a 100 mL 10°P DME (dry malt extract) starter six days before the brew day. Then transferred the yeast cake from the first starter into 1 L of a 10°P DME starter a day before brew day. The density of this starter was 64E6 cells per mL at the end. So I added roughly 780 mL of the starter to have the right pitching rate of 5E6 cells per mL. Unfortunately, I forgot to include the starter liquid into my dilution calculations to reach the planned OG of 13.8°P after the boil. The yeast starter therefore diluted my wort’s OG down to 12.8°P. But now I have an additional 780 mL of beer…

Fig 1: Open fermentation is over

After aerating the wort by vigorously shaking the fermenter, I removed the lid and let it sit there without any protection for the whole duration of the fermentation.

The fermentation kicked in within hours and a big kräusen formed after 12 hours. I checked the fermentation after six days, and the kräusen was gone (Fig 1). I originally planned to rack the beer just before the kräusen started to vanish. But I had a pretty busy week and forgot to check the fermentation… So I just bottled the beer after seven days after fermenting. There was a pretty nice caramel, malty and hints of banana smell noticeable.

03/31/12: Bottled the beer into bottles and added sugar to reach a carbonation level of 3.5 vol of carbon dioxide. The terminal gravity of the beer was 5.2°P. This seems to be pretty high compared to other brews. But my previous Dunkelweizen batch (exactly the same recipe) finished at 5.6°P and I had no problem with gushing bottles etc. The bottles will carbonate for a week and then maturate in my refrigerator for three weeks. I hope no other bugs such as Acetobacter got into the wort… So stay tuned for the tasting results!

06/01/12: Tasting