Berliner Weisse Small Batch

Later in this post I'll include some links to some very well written technical information on how to perform a sour mash and specifically how to approach a sour mash to produce the berliner weisse style of beer.  My focus will simply be on my steps to produce a small batch, 1.6 gallons, of berliner weisse style beer.

Full allotment of hops!

I decided to brew a 1.6 gallon batch, enough to fill two 1 gallon fermenters with .8 gallons of wort.  Additionally rather than use the traditional approximate 50/50 pilsner malt/wheat malt ratio grain bill I went with a 70/30 US 2-row/rye malt grist.  For 1.6 gallons I used 33 oz of grain total along with 1/10th (2.8 grams) of an ounce of 7 AAU Cluster hops at 40 minutes in a 40 minute boil.  Due to the challenges of maintaining temperatures for such a small mash in my 5 gallon cooler style mash tun I mashed on the stove top with a mash liquor ratio of approximately 1.15 quarts water per pound of grain.  The target mash temp. was 147 degrees f. as you want this beer to finish very dry from around 1.030 down to approximately 1.006 or lower!

Bucket o'mash in the cooler with 122 degree water.

Here's where the fun begins, the sour mash.  After my saccrification rest I cut the lid off a 1 gallon jug of water saved from a previous brew session, sanitized thoroughly with star san, and dumped the mash into the jug.  The jug containing the mash is placed in a cold water bath in the sink to bring the temperature down to around 122 degrees.  I then added 4 oz. of unmilled 2-row, stirring it in thoroughly to disperse equally among the mash.  Of note here is that most literature says something to the effect of 'throw in a hand full of grain' or a couple ounces for a 5 gallon batch.  I purposefully over inoculated believing in the theory of adding as many Lactobaccillus delbruckii bacterium as possible theorizing they would 'out compete' less desirable bacteria.  Adding the unmilled-unmashed grain is how we inoculate our mash with Lactobacillus delbruckii to produce the desired sour effect.  I then placed this jug inside a cooler with 122 degree water inside, closed the lid and placed something heavy on top of the cooler lid to maintain a tight seal and minimal heat loss.  From there it was a matter of waiting and changing the cooler water bath every 4-8 hours to maintain temps as close to 120 as possible.

Plastic wrap with few bubbles helps to keep oxygen out.

A note here, it's fairly important to keep the sour mash at 115-120 degrees f. and keep the mash covered with plastic wrap to inhibit the growth of less desirable bacteria present in most any sour mash.  Here are the links I promised earlier covering the technical aspects of a sour mash berliner weisse.

Chris Colby's excellent Sour Mash article 

Dave Green's 2008 BYO article

Sean Coates' blog post of his experience

I waited 49 hours allowing the sour mash to do it's sour thing, then treated the mash and wort as you would any normal beer.  It was at about 40 hours into the sour mash that I first tasted the mash.  It was nutty and lightly bready up front, tart, acidic, reminded me of lemonade.  Before briefly covering the remaining process I'd like to share that my sour mash was exceptionally clean simply smelling a little sour and little else.  A brief search will provide dozens of accounts of exceedingly smelly sour mashes.  I attribute my relatively clean mash to my inoculation rate, keeping the mash covered with plastic wrap, and attention paid to keeping the mash temps between 115 and 120.  I dumped the mash into my standard mash tun along with a quantity of boiling water to bring the temperature up into the high 160s.  From there I batch sparged, an oddity for me, producing a very low efficiency which I expected with such a shallow grain bill.  

Dense foam at the start of the boil is typical for this style.

As noted above I performed a 40 minute boil.  Some berliner weisse are not boiled at all while others undergo anywhere from a 5 - 60 minute boils.  The boiler was placed in an ice-water bath for chilling to around 70 degrees.  1/3rd package of Nottingham dry yeast was pitched into each one gallon fermenter.  This was a rather large over pitching rate, performed on purpose.  The thought with the pitching rate was to produce as clean a fermentation as possible even though fruitiness is tolerable within the style.  The fermenters were placed in a water bath-less swamp cooler with a constant air temperature of 58 degrees.  I'm trying to get a fermentation temperature of 60-61 degrees, quite cold for an ale yeast but Nottingham yeast can handle it!

Here is the recipe:

Size: 1.6 gallons

Grain:

1 lb 8 oz US 2-row pale malt - 73% of grain bill

9 oz rye malt - 27T of grain bill

Hops:

2.8 grams or .1 oz of Cluster at 7.0 AAU - target IBUs 7

Yeast:

Danstar Nottingham dry ale yeast

Extra:

1/2 whirlfloc tablet @15 minutes left in the boil

O.G. 1.029

F.G. 1.007 (estimated)

SRM 3

BU:GU .21

ABV 2.9%

Calories 111 per 12 oz

If you'd like to read further about the profile of this bubbly low alcohol beer proclaimed by some to be the most refreshing beer in the world I suggest reading the bjcp style guideline here: BJCP Berliner Weisse Guideline.