“A sour wort Berliner weisse aged 8 weeks on cherries and kumquats with a ghost of an ABV.”

Berliner weisse is a classic tart German wheat ale that is traditionally fermented with a mixed culture of top-fermenting yeasts and lactobacillus.  Examples of the style can range from mildly tart to bracingly sour with firm acidity and notes of lemon and other citrus fruits.  In Berlin it is available “straight” but is often served with sweet raspberry or woodruff syrups to blunt the acidity and sourness.  At only about 3-4% alcohol by volume this beverage proves to be an excellent thirst quencher and has become quite popular during the summer months in the U.S.A.

There are different methods of souring a berliner weisse, each with its own involved process and merits.  Briefly, you can pitch pure strain lactobacillus, or lacto with an additional yeast culture; or you can do a sour mash with pitched yeast, or a sour mash with pitched yeast and additional lacto.  If you’d like to read more in depth about these methods, Derek Dellinger has done a great job of explaining them on his Homebrew and Beer Blog, Bear Flavored.  Additionally, you can conduct a normal mash and pull some or all of the wort, pitch your lacto starter at this point and perform a sour wort.

The base for this berliner weisse is extremely minimal.  Gregory and I decided to do a four day sour wort with a lactobacillus starter made from yogurt followed by a 15 minute boil after which we pitched Wyeast 1007 German Ale along with Wyeast 5112 Brettanomyces Bruxellensis.

As the tag line that begins this post suggests, not everything went as planned for this brew.  Although some might consider 3-4% a ghost of an ABV already, the base beer only ended up being about 1%!  How did this happen, you ask?  Well I have a few theories though I’d love to hear others if you’ve got them.  First of all, while hot holding the sour wort at around 100F for the four days, it began to ferment creating some alcohol that would later be boiled off (since we only boiled for 15 minutes to kill the lacto/other bacteria I’m unsure if this had much of an affect on the finished product).  Additionally, I forego a starter for the German Ale yeast (this was brewed at a time before I always made a starter) and assume that the PH was too low, disrupting the ale yeast’s fermentation.

Regardless of the reasons for the lower than usual ABV, the beer went through a 16 day primary fermentation followed by a 56 day secondary on cherries and kumquats.  In addition to the final refreshing brew tasting fantastic, the “sessional” aspect of this already session style beer allowed it to be entered into Xbrew — the Mount Si Brewing Society’s annual homebrew competition that accepts session and imperial versions of each traditional BJCP style.  I am honored that this little beer took the silver medal in the fruit beer category.  I plan to brew this recipe again although I haven’t determined which souring method I’ll experiment with.  The recipe is as follows:

Cherry Ghost Berliner Weisse

Recipe Specifics

Batch Size (Gal): 5.0
Total Grain (Lbs): 8.2
Anticipated OG: 1.047
Anticipated SRM: 2.0
Anticipated IBU: 6.0
Brewhouse Efficiency: 75%
Wort Boil Time: 15 Minutes

Grain

43% – 3.6 Lbs. Belgian 2-Row Pilsner
43% – 3.6 Lbs. White Wheat
12% – 1.0 Lbs. Acidulated Malt

Hops

0.50 oz. US Cascade (Pellet, 7.0% AA) @ 15 min.
1.00 0z. Columbus (Pellet, 15.0% AA) @ 3 day dry hop.
0.40 oz. Galaxy (Pellet, 14.2% AA) @ 3 day dry hop.
0.25 oz. Amarillo (Pellet, 9.3% AA) @ 3 day dry hop.

Extras

1.00 Whirlfloc @ 15 min.
1.00 tsp Yeast Nutrient @ 15 min.
9.00 Lbs. Pie cherries
2.00 Lbs. Kumquats
0.50 Lbs. Rainier Cherries
0.50 Lbs. Red Cherries

Yeast

Wyeast 5112 Brettanomyces Bruxellensis
Wyeast 1007 German Ale

Water Profile

Seattle
1.00 tsp Calcium Chloride
1.00 tsp Gypsum

Mash Schedule

Single Infusion – 60 min @ 150F

Notes

04.05.14 – Made a lactobacillus starter from yogurt (but didn’t give it enough time to culture up)

Mash & sour wort 04.07.14 with Gregory

04.07.14 – Hot held wort @ 100F for 4 days

04.09.14 – Temp drop to 80F, pulled some wort, brought it to boil and added back into water cooler mash tun to raise wort back to 100F

04.10.14 – Noticed signs of lacto fermentation

04.11.14 –  Brought wort to boil for 15 minutes to kill lacto/other bacteria

04.11.14 – Chilled wort to 65F before pitching German Ale yeast and Brett.

04.27.14 – Pasteurized 9.0 Lbs. frozen pie cherries by adding them to water and raising to 165F, used StarSan on 2.0 Lbs. kumquats

04.27.14 – Transferred beer to secondary and added the fruits

06.09.14 – Added 0.5 Lbs. Rainier cherries & 0.5 Lbs. red cherries

06.20.14 – Transferred beer into bottling bucket and dry hopped for 3 days

06.23.14 – Bottled Berliner weisse with 6.2 oz. corn sugar @ 3.45 volumes of CO2

Tasting Notes

Great summer quencher — light and crisp with a slight mineral note announcing itself after the tart finish.  The fruit is spot on; big sour cherry flavors and some citrus from the kumquats.  It actually seems that the kumquats have become more apparent over time.  I’m excited to make this one again.

Calculated OG: 1.014
Calculated FG: 1.006
Approx. ABV: 1.05%