Cherry Sour

With the apparent failure of my Flanders red to sour (aside from the partial gallon batch done with raspberries, which turned out pretty nice), I’ve been hungry to find success with a sour beer.  With the approach of summer and our imminent move, however, I only had a matter of months to produce it; while I look forward to letting wave after wave of different bugs produce a richly layered, sour and funky beer over the span of many months and years, it’s not going to happen before we head west.  I’ve produced three Berliner weisses in the last few years, the first turning out the best (most sour and to style), so I turned once again to my friend lactobacillus to produce the sour I crave.

Michael Tonsmiere’s Mad Fermentationist blog has been a guide and inspiration in my journey into funk; without serious contender, it’s my favourite brewing blog.  Having read his post on sour worting some time ago, I finally gave it a go myself; other sources I considered for this project included a long thread on Berliner weisse brewing on the NB forum and a recent article in Zymurgy on quick souring.  I made a sour starter with some brown sugar and uncrushed Munich, kept between 90 and 100F; the low gravity sugar water and warm temperatures (up to 120F) provides the lacto present on the grain husks ideal conditions to grow.  Having given the starter the best part of a week to get really disgusting and sour as possible, I made up a simple moderate-gravity wort of 2-row and wheat, brought it to a boil to kill off any bacteria present in the wort itself, cooled it to about 115F, and pitched the starter.  The wort then went

into the swamp cooler in the brewpot, covered in plastic wrap with as much air pushed out as possible to inhibit aerobic bacteria growth.  It was kept warm (around the same temps as the starter) for five days to get as sour and nasty as possible.  Once the wort was sufficiently sour (and smelling relatively unpleasant) I treated it like any other beer: I gave it a full 60-minute boil with a small amount of bittering hops, chilled it, and pitched the yeast.  Looking for a clean ferment, I went with US-05 at reasonably cool temps.

The pre-fermented wort (post boil) already tasted pretty darn tart; I was a little worried it would be a violent, enamel-stripping machine once it fermented out.  Once primary was completed, though, it had a pleasant, bright acidity that begged for a hot day and a large goblet.  I wasn’t done with it yet, though.  The Mad Ferm blog mentioned that the sourness this method produces is very one-dimensional when compared to traditional slow-souring methods, and suggested adding another layer of flavour to complement the acidity and add to the overall profile.  As DeAunn has especially liked dosing Berliner weisse with a small amount of fruit syrup (as is traditional), I made my “extra something” a healthy hit of cherry.

To the secondary I added a gallon of Knudsen’s cherry juice, half black cherry, half tart, and a 16-ounce bottle of Montmorency cherry concentrate, which, according to the bottle, has been pressed from over 1,000 cherries.  Needless to say, on its own it’s pretty damned potent.  All of the cherry juice and concentrate was pasteurized, so I didn’t worry about infection from it.  Entering secondary, the beer gained a deep red colour from the cherry and came up to just over 6 gallons in volume.  I put the fermenter in the swamp cooler with water that was about 60F; I wanted to preserve as much of the cherry aromatics as possible during the secondary fermentation, which would be blown off if it got too violent.

After several weeks in secondary, the cherry had fermented out almost completely, and I bottled a very pink, fairly sour beer.  Despite the low secondary temps, the flat sample didn’t display much in the way of cherry flavour or aroma; given that it feremented out so far, I suppose I shouldn’t be surprised.  If I try this again, I might bump up the amount of cherry even more.  At this point, it seems like what I’ll end up with is a pink Berliner weisse; while that’s not quite what I had in mind, I won’t be upset if that’s what comes of it.  For more fun next time, I might try using a Brett strain for primary to follow the sour worting to layer on the funk with the straight sourness.  I also forsee using this method to add a touch of sourness to a porter for a more "authentic" quality.

Cherry Sour

Batch size: 5.2 gallons
Projected OG: 1.044
Projected SRM: 3.2
Projected IBU: 10.7
Boil time: 60 minutes
Brewhouse efficiency: 77%

Grain
53.9% - 4 lb 5 oz Belgian Wheat
46.1% - 3 lb 11 oz 2-row

Hops
.2 oz Columbus (14.5%) (60 min)

Yeast
Sour starter (pre-boil)
US-05 (primary)


Extras
1 tsp Yeast nutrient (pre-sour boil)
1 tsp Yeast nutrient (10 min)
1 tsp Irish moss (10 min)
1 qt Knudsen Just Tart Cherry Juice (secondary)
1 qt Knudsen Black Cherry Juice (secondary)
1 pt Cherry concentrate (secondary)

Water additions (mash)
1 gal RO water
2 g Chalk
2 g Baking Soda
1 g Gypsum
½ tsp Acid blend

Sour starter: 6 May 2011
Boiled 2.5 oz dark brown sugar in 1 qt water
Cooled to 110F in Mason jar, added small handful of uncrushed Munich
Kept 90-110F to encourage lacto growth; grew some chunky funk and aroma; hard to discern sour flavour amidst sugar sweetness

Brewday: 11 May 2011
Mash-in: 13 qts @ 152F for 12 hours - dropped to 116F
1st sparge: 9 qts @ 212F - added to mash to extend sacch rest - settled at 152F for 15 minutes
2nd sparge: 10 qts @ 212F
Pre-boil volume: 7 gallons
Pre-soured SG: 9P (1.036)
Brought to boil, cooled to 115F, pitched sour starter, covered in plastic wrap, kept warm in swamp cooler

15 May 2011: Normal boil for 60 minutes with hops, chill & add yeast as usual
Smelled mildly awful coming out of the cooler, which changed to tart during the boil
Post-boil volume: 5.2 gallons
OG: 11P (1.044)
Quite sour already, unfermented; almost afraid this will be undrinkable

Fermented in basement at ambient (62F)

Secondary: 26 May 2011
Added cherry juice & concentrate first, splashed a bit to aerate; fermented out below 60F in swamp cooler to preserve as much of the aromatics as possible

Good tangy lactic sourness; very quaffable.

Cherry juice mix SG: 21.8P (1.092)
SG (w/o cherry): 1.009
SG (w/cherry): 1.024

Bottled: 15 June 2011
Composite OG: 1.053
[(1.044 x 5) + (1.092 x 1.125)]/6.125 = 1.053
FG: 1.012
ABV: 5.3%

Bottled 6 gallons with 6.4 oz table sugar