Pitching with sourdough starter experiment

[Captain Damage]

Note: I found and read this thread today before posting this. For whatever reason, it didn't show up when I searched before starting this experiment.

98 days ago (1/27/2013) I brewed a beer and pitched my sourdough starter instead of a conventional brewing yeast. I'm posting now because I just bottled four bottles. I'll continue to bottle a few every month or so.

The recipe is about as simple as they get:
3 Gallon Batch
5½ lbs 2 row
½ oz cascade @ 30min
Mash @ 154F for 75 min
OG: 1.060 IBU: 18 IBU/OG: 0.3
I pitched 150ml (5floz/5.5oz) of active sourdough starter which I'd been growing for about 4 months. It was grown from the Culutres for Health New England Sourdough Starter, which makes a tasty, but only very slightly sour bread. In retrospect, this was probably underpitching by quite a lot, but it did begin fermenting pretty quickly, if not as vigorously as a usual pitch of ale yeast.

The bottles I filled today have a single Cooper's carb tab in each. The FG is 1.004, yielding an ABV of 7.4% The beer tastes sightly sour, with no sweetness to speak of. It has no objectionable or spoiled flavor. It's hard to determine the pH since I don't have a meter. I have the test strips for both beer and wine and they both show the pH at the lower and upper limits, respectively, making the pH probably about 4.4.

I'll report back as this experiment continues.

 

[GuldTuborg]

Interesting experiment. Post back when it's carbed and ready to drink. I'm curious to see how this works out.

I've always been curious to try the opposite route: take a lambic beer, or something similar, and make bread using the dregs as a starter. Haven't gotten around to it yet, though.

 

[afr0byte]

If the beer actually tastes sour, I'd wager it's lower than a pH of 4.4. That's a normal finishing pH for a non-sour beer. Did you add a lot of acid to your mash to get the pH down initially?

 

[DPBISME]

After reading about a 100% Lacto Berliner-Wiese I went out and looked up some "pickling" cultures.. Some of them had more than one strain Lacto and I assume you could to the same thing with one of those...

 

[Hermit]

I've read that the wild lacto is not the same as what is normally used in beer. Indigo Imp in Cleveland does 'open fermentation' and their beer is down right nasty to my pallet. A lot will come down to how quickly and completely the yeast did their work and what was left for the lacto to continue on.

 

[Captain Damage]

If the beer actually tastes sour, I'd wager it's lower than a pH of 4.4. That's a normal finishing pH for a non-sour beer. Did you add a lot of acid to your mash to get the pH down initially?

I think part of why it tastes a little sour is that there's no longer any noticeable sweetness, which is why I decided to bottle a few. Three weeks ago there was still some sweetness, and the pH reading was the same (if this was a "normal" ale, I'd expect a high residual sweetness with such low hopping). The pH is part estimate, part guess. As I said, the reading on both strips were at the limits, which is where the accuracy gets poor anyway.

I didn't do any pH adjustment (or testing) to the mash.

 

[Captain Damage]

Tasting!
Poured with a nice creamy head that sustained through the whole glass and left some lacing (Coopers carb drops I used do not contain a heading agent - other brands do). Tastes good! Little bit of a "Belgian" flavor, but not "barn yard-y." The sourness is slight. There is a little sweetness, which I didn't taste when I tasted my testing sample two weeks ago, but it's not cloying. There is s slightly bready aroma. No hop aroma t speak of, but wasn't really expecting any with the hop schedule I chose. Cloudiness in the pic below is just chill haze (beer in the room temperature bottles is clear). I'll bottle a few more next weekend or the week after and keep reporting.

 

[signpost]

Awesome expirement. I'm definitely interested in the further tasting results.

 

[Captain Damage]

Day 127, roughly 1 month after the first bottling. I took the t-shirt off the carboy and there is now a pelicle! SG is 1.003, pH is about 4.0. Sample tastes a bit more sour, but decided not to bottle any more this week. I'll check again in 2-4 weeks. Again, beer does not taste "spoiled."

 

[GuldTuborg]

Interesting stuff. I imagine the sourness will continue to slowly rise, but I could be wrong. Keep the updates coming. I'd love to see how this continues to change over the next few months.

 

[Captain Damage]

After this experiment has run it's course, the next phase will be to pitch the sourdough culture into one of my standard beers - something with a more "normal" hop level in the 0.5-0.7 (BU:OG) range and more flavorful grain bill. I'd like to do a split batch and make the same beer with a traditional ale yeast. Bottle some of the sourdough-pitched batch at the same time as the normal batch and compare. I chose a low BU:OG ratio for this first experiment mostly because sour beers are traditionally only slightly hopped.

 

[Captain Damage]

Bottled 157 days after pitching. Two weeks in bottle with one Cooper's tab.

Much more pronounced sour taste (pleasant, not puckery); sour taste is lactic, not acetic; bready aroma; slight cider flavor; hints of Belgian character, but not barn-yardy. No HEAD!

PH at bottling was about 3.8, gravity 1.003, ABV 7.5%.

 

[GuldTuborg]

Is it even carbonated yet? That's, what, two weeks in the bottle? Maybe there isn't enough carbonation for a full head yet. Don't see any bubbles in the glass...

 

[Captain Damage]

It was carbonated. I'll try another this weekend to see if there's much difference. There is chill haze in the glass pictured so bubbles are hard to see. The glass was clean - enough so that a beer poured into it after I finished the sour one had a normal head. I thought the lack of head was interesting because the first bottle I tried, from around 98 days, had a very nice creamy head.

 

[Captain Damage]

Tried another from the last (day 157) bottling and still no head. Slightly more carbonation than before - that's at 3 weeks in the bottle. So I don't believe the no head issue is a carbonation issue. I think the culture is eating the higher sugars, dextrins or whatever contributes to a thicker head. Recall that the recipe had only pale malt, no caramel or wheat, or anything that might contribute to head.

I'm also thinking that the next bottling, which will probably be the last, I'll use two carb tabs per bottle instead of one. I think a higher carbonation level will brighten it a bit.

 

[CptnRedbeard]

Cool experiment. I just thought of doing this last night when I saw my two brewing starters sitting on the counter next to my freshly fed sourdough starter. I'm glad to see it went well enough. I'm guessing that, like sourdough bread, location would make a huge difference. Since I'm on the very opposite side of the country, I'd have different wild yeasts. If I try it soon, I'll put up my results for comparison.

 

[Captain Damage]

More information than you require, but I'd tried a number of times to get a sourdough starter going spontaneously, but couldn't get anything to work. In retrospect it was probably just impatience, but in any case I wound up buying a starter culture off Amazon. The one I got is a "New England" type, figuring it would change the least as I continued to maintain it. It has changed quite a bit since I first got it, but hard to put my finger on exactly how - and of course, the way I make my bread has evolved as well, so there's the whole cause-and-effect question. The bread this starter makes is only slightly sour after a twelve hour rise.

 

[Captain Damage]

Day 211. Just bottled the last 12 of this experiment. The gravity sample had a sherry (oxidative?) aroma and a noticeable acetic/vinegar flavor. I'll post tasting notes in 2 or 3 weeks after it's bottle conditioned.

FG 1.003; ABV ~7.5; pH ~4;

 

[breckenridge]

Followed. Very cool thread.

 

[Captain Damage]

This is the final bottling. I bottled this back in August, but I delayed reporting on it because it's not carbing up. It may be at the ABV or pH limit for the culture. In any case, it's very poorly carbed.

It was bottled 211 days after brewing. The stats haven't changed enough for me to measure accurately: FG: 1.003; ABV ~7.5; pH ~4.

Taste is awful! It has a strong sherry-like aroma you can smell from across the room. The bready flavor is more pronounced than the previous bottling. The lactic tang is accompanied by an acetic (vinegar) bite. The combination of these flavors, IMO, is pretty gross, so I dumped it after a couple of sips. The sherry aroma and acetic flavor is almost certainly a product of oxygen introduced when drawing off beer for previous bottlings. So it's hard to say how it would taste if it had been left undisturbed.

The previous bottling (day 157) is okay-enough that I might try further experiments along these lines with a 150 day target and a more interesting beer. But I'm in no hurry. I mostly just wanted to see what would happen. Different sourdough cultures will give different results, and I'd be interested in hearing about results from someone trying this in another part of the country (or the world).

 

[Thunder_Chicken]

You might want to check out kvass. It's a very light beer made from steeped rye bread and is soured using a lacto-yeast blend similar to sourdough starter. It is a very quick beer, only a few weeks to make and drink.

 

[Captain Damage]

Some new(ish) developments:

Around Christmas time I gave some of the "good" bottling (day 157) to some friends and they liked it very much. I eventually got around to sending some to James Spencer, host of the Basic Brewing Radio podcast. He liked it as well, and interviewed me about it last week for an upcoming podcast (I'll post a link when it's released).

These positive responses have convinced me to move this beer from the "that weird thing I did one time" department into the "recipes to continue refining" department. I have some ideas towards this end such as standardizing the fermentation time at 160 days; adding wheat to the grist to combat the headlessness; and certain specific hops and hop schemes I'd like to try. I'll have to get another fermenter or two!

 

[Captain Damage]

Direct link to my interview on Basic Brewing Radio (mp3) is here.