Kettle Souring

I got the tip on how to do this from Tim at the Dry Dock Brewery.  He’d given us a taste of his “Regal Tang” so I asked where the pineapple and mango flavors came from.  Turns out he’d used yoghurt to pitch lacto into hot wort, left it overnight, then boiled with hops the next day.

So I tried a batch.  I mashed, ran off the wort, boiled it for ten minutes, stuck a thermometer probe into it and cooled it to 120 degrees.  At 120 degrees, I pitched a couple teaspoons of my sourdough starter into it, insulated the heck out of it (as best I could), then left it overnight.  The next morning I checked the pH.  It was about 4.1, I wanted in the vicinity of 3.5.  I let it set a couple of hours then checked again.  4.0.  So I turned my hot plate on low.  The wort began to warm very slowly.  Seeing that it wasn’t about to get away from me, or so I thought, I went upstairs to take a shower.  When I came back to the wort, the pH was 3.9, okay, but the temperature was 151 degrees.  I’d killed my lacto.  So I boiled, fermented and still got a pretty good beer out of it, not as tart as I’d like but still nice.  Unfortunately, I didn’t take pictures.

New procedure involves my Inkbird temperature controller.  It controls both heating and cooling.  I generally use it to control my fermentation chamber – it’s holding the temperature above room temp for my 90-degree Belgian Saison.  Next batch I run my hot plate through it controlled to 120 degrees (50 celsius) with the probe in the wort.  The controller in Celsius mode holds the temperature to +/- 0.3 degrees, effectively 1 degree Fahrenheit, and the temperature is adjustable to 0.1 degree Celsius.  Interesting because the actual conversion of 120 degrees F is 48.9 degrees C.

So why kettle sour when there are other alternatives such as sour mashing, Brett fermentation, wild yeast, sour blends.  The literature will tell you, at least the snobbish parts, that kettle souring lacks “complexity” compared to other souring methods.  Here are my reasons for kettle souring above the others:

1.  It’s very controllable.  Some other methods give you what you get.  Souring in the kettle leaves you in control – you can stop the process at whatever level of tartness you want for the effect you want.  I’m even thinking of a very short kettle souring for my next batch of Irish Stout, since Guinness is rumored to use stale (read old), slightly soured beer in their blending process.

2.  You don’t contaminate equipment.  You boil the kettle after souring, killing off all the lacto before it can infect your next batch.

3.  It’s fast.  No waiting for a year or so for your Brett or your Lacto pitch to sour the beer.

4.  You can even control what you pitch.  Yoghurt works, sourdough starter works, natural sauerkraut would work, even pitching grains would provide lacto.

5.  Less chance of the enteric bacterial stench.  No need to stink up your work area.

6.  Most important, I like the results.

Sourdough Blonde – An Adventure in Kettle Souring

Sometime last year Tim, the head brewer at the Dry Dock South, led me into the back and handed me a sample from one of the fermenters.  It was nice!  Tropical fruit flavors, some lactic smoothness on the tongue, tart and clean.  So I asked the secret and he told me, a pitch of organic yoghurt once the wort had reached 120 degrees then keep it warm overnight.  By morning the pH was in the 3.5 range.  From there, boil as usual.  So I tried it.


This is Sourdough Blonde at eight days in the bottle.  Instead of the yoghurt pitch, I used a couple teaspoons of my sourdough starter as the lacto source.  She came out very nice, not as tart as Tim’s due to an error on my part, more on that later.  But the tropical fruits – pineapple and mango – are there, some malt flavor is still to be found despite the souring.  It has some body and is a pretty beer.  I’m happy with it!

My error was temperature control during souring.  I chilled the wort to 120 degrees, pitched my sourdough and insulated the heck out of the kettle to keep it warm.  By the next morning it was in the 90’s, warm enough for lacto but cool enough to allow some unwanted bugs to take hold.  So I started applying heat using a hot plate.  It looked as if all was well, the temperature was holding between 110 and 120 degrees F so I went to take a shower.  When I came back, it was 150 in the kettle, all my lacto were dead.  The pH had only dropped to around 4 but there was nothing to do other than to continue processing.

She came out good, though.  And I got a two-stage temperature controller so next time, the hot plate will cut off at 120 degrees.  More on kettle souring later. Here’s the recipe:

Kottbusser Recipe

Having seen a search request land here, here’s my Kottbusser recipe.  It’s currently scaled for 10 gallons for brewing on the Ruby Street Brewing 10 gallon rig.

Yesterday’s experiment told me that next time I’ll sour mash the brew.  To do that, make your wort as usual but chill down to 120 degrees.  Pitch lactobacillus in one of two ways, either as a culture you bought or through throwing a few grains of malt into the warm wort.  Keep air away from the wort to avoid culturing acetobacter – you’ll get a vinegary taste if you do.  To keep air away, either cover the wort with plastic wrap and by that, I mean floating the plastic on the wort, or use a blanket of carbon dioxide to keep oxygen away from the wort’s surface.  In 12-24 hours, take a sample and if it’s tart enough, boil and add your hops.  Caution:  Don’t let anything you can’t sterilize fairly harshly come in contact with the soured wort.  Lactobacillus can be hard to get rid of once you have it.  I keep a separate setup of buckets, racking canes and so forth for anything soured.  I sour the mash in my kettle since it will be boiled and everything else is very clearly marked.  Duct tape is good for this.

Chances are the original beer was soured after the boil.  Lactobacillus Delbruckii is sensitive to hop oils so it won’t work quickly as a culture once the beer is hopped.  Lactobacillus Brevis is not but it will require very careful handling – it’s a very aggressive spoilage bacterium!  To sour in storage, again, cool the wort to 120 degrees.  Innoculate the wort and let it cool slowly for a few hours to let your lacto get going, then finish cooling and pitch brewer’s yeast.  Let the beer ferment, then bottle or keg as usual.  The beer will sour slowly, taking up to three months to develop tartness.

Hat tip to Ron Pattinson for tips on the recipe and techniques used to develop this recipe.

Brew in a Bag

Sunday night John Brindle gave a great talk on the Brew in a Bag technique at the Aurora City Brew Club (AC/BC) meeting.  Brew in a Bag, really mash in a bag, involves the use of a mesh bag to contain your grains during mashing.  Lautering then involves raising the bag up out of the wort and letting the bag drain.  The original technique was no-sparge but now a “teabag” sparge is used to get conversion rates near or in some cases even above what you can get with a picnic cooler mash/lauter tun.

I’ve used BIAB for some of my small batches but in the conversation after the talk, we arrived at another great use:  Developing recipes.  Since I was in Poland this year, I have wanted to brew a Baltic Porter.  It’s a really big beer, 8 to 8.5% ABV.  It also provides a chance of making nineteen liters of very expensive swamp water, so I intend to use BIAB for very small batches (one gallon) to dial it in before scaling up.  More great uses of the technique are testing malts, SMASH (Single Malt and Single Hop) batches or any other brew where you may not want 50 bottles of whatever it is you could be brewing.

BIAB requires minimal equipment above extract batches.  The technique is described very well in many places on line so I won’t go into it here.  Another advantage is a shorter brew day – I can turn out a batch in an evening as opposed to six to eight hours for my larger brews.  It’s a weapon in the homebrewer’s arsenal, to be used when it’s appropriate.  And I can testify to the quality of beers produced.  John’s are excellent.

Two22 Brew/Brew Day

A busy couple of days.  Yesterday I was out running errands and they took me to the vicinity of Two22 Brew, actually the closest brew pub to me and very near my old house.  It’s a typical Colorado tasting room:  You go in and buy beer in what ever volume the publicans choose to serve.  My first choice was a flight of their beers:


It’s an American Pale Ale (already done in this pic), a Saison, a Blonde and two IPAs, one a “Two Hop” and the other a Simcoe IPA.  All of the beers were sound and good, the winner to my taste was the Two Hop IPA, the one I later got a half-pint of.  The brewer was not there.  I’ve talked with her before, though, and hope to get over there one evening this week and compliment her on her brews.  You have to google “two22” to find them, a drawback to their clever name, but it’s worth it and damn, I’m bummed that they weren’t there when I lived within walking distance.

Today was brew day for Dusseldorfer Altbier, named “Hopfenkopf.”  Dusseldorfer Altbier is the original German hophead beer with a very high BU/GU ratio.  I brewed mine to 50 IBUs and an OG of 1.050, pretty much a BU/GU ratio of 1.  Here we go:


Now that’s a fine looking grain bed!  I got 80% conversion, leading to an original OG of 1.055, higher than I wanted.  A couple quarts of water later the gravity was where I wanted it, it’s pitched and in the fridge.  Altbier calls for a carefully controlled fermentation below 65 degrees until finished, then a “lager” phase at about 40 degrees for a few weeks.  I’ve never tasted the style but a friend is leaving for Germany soon and Dusseldorf is on their list of places to go.  I’m expecting a full critique once they get back.  The particulars on the beer:  OG1.050, 50 IBUs, about 14 SRM in color (copper).  Primarily Pilsner malt with Munich, CaraMunich, Vienna and a touch of black malt for color.  Hops were Perle (bittering) and Spalt so there was a lot of hop material in there.  It should finish at about 4.6% ABV, sessionable.  Key is this is a flavorful beer and mine should be.

I’ll make the recipe available here on request or cross-link from Brewer’s Friend.

Brewing Update

I racked the “Short Cut Brown” tonight.  So far so good.  It’s down to 1.022, should reach 1.015.  It should be anything but a “boring” brown, likely very different from the Texas Brown Ale that originally defined the style.  I’m pushing the limits of style, going as big as possible in both malt and hops, trying for a beer that while drinkable in large amounts is also enjoyable.  In other words, typical American brewing:  Go big or go home.

Sunday I intend to do another big, bold beer with a session ABV, a Duesseldorfer Altbier.  Starter’s spinning away, everything else is on hand.  I’m going for a big malt flavor and lots of hops in typical Zum Uerige style.  Interestingly enough, I’ve never tasted the example I’m following so I’ll wait for a friend to return from Germany and let him tell me how well I matched the style.  I thought about doing a Kentucky Common but I have even less an idea how that should taste once finished – best definition I have is a dark cream ale with a lot of adjuncts in the mix.  There’s not even agreement as to whether the style, a partial inversion of a sour mash whiskey mash, was sour or not.  I tend to believe it wasn’t, although I’ve tried souring it in the past.  By the time Common was being brewed in northern Kentucky, metal vessels were common.  The style mostly died in Prohibition, it’s been revived by a few craft brewers and a few homebrewers.  So we won’t know how it tastes but at least we can make a beer that tastes good.


Schwarzbier Packaged

The next version of my award-winning Schwarzbier is bottled.  Here’s the bounty:


Sorry for the darkness – it’s dark in my basement.  This version is likely my best yet – dark, malty, dry.  It’s a good beer and I’m closing in on my “perfected” recipe, the right balance of Carafa and Chocolate malt.  Next version should be just about there