Sourdough III: The Search for Spock

Last month, I killed my second batch of starter. This was a good thing, for reasons I’ll comment on later. I decided to purchase some “professional” quality sourdough starter from Sourdo International, the company Ed Wood, author of Classic Sourdoughs

I went a little wild — pun intended — as evidenced by the number of varieties I purchased:

Given my natural propensity for attempting the hardest thing first, guess which I chose? I’ll give you a hint: the only one that uses whole wheat flour. Wheat flour is more difficult to work with because it’s got all that healthy stuff in it like bran and germ. It rises slower, and not as much. They don’t make Wonder Bread with whole wheat.

The first step is to create a stable environment for the starter to activate. Temperature is critical when activating because the sourdough cultures are competing with whatever else is in the flour. For the starter box, I used a $2.50 styrofoam cooler. I drilled out the top enough to put a standard light socket through. Midway on the side, I poked through an instant-read thermometer.

Child’s eye view Socket goes through the top Light affixed to inside An instant thermometer montitors the results

I ran it for an hour with the 25W bulb and measured the temperature: 127°F, much too hot to sustain life. Ideally, I’d be able to maintain 85°F for best results. The selection of low-wattage, standard socketed bulbs isn’t too good. My next option was a 7 1/2W nightlight from the kids’ bedrooms. It was able to maintain about 83°F, but only if the mixture is very close to that range to begin with. When we have cold nights, temperatures drop down to the upper 70s. This isn’t optimal, but will slow the culture development. After I get a hang of this, I will revisit the 25W bulb with a dimmer, then calibrate the dimmer settings for night and day differential.

What starter should look like The liquid at the top is alcohol.

I activated the starter by adding 3/4 C warm water and 1 C flour. The next morning, I saw a lot of bubbles, there was a layer of liquid on the bottom, and the overall mixture was acrid. The flour was contaminated.

Next week, I’ll explain a little more about how sourdough works. However, in this case, “contamination” refers to non-sourdough organisms and is not surprising that this happens, even with a brand name flour like the one I was using. Dr. Wood confirmed that this is what was occurring, and emailed me a two page summary of an experiment he did with a contaminated mixture.

The solution to this is to “wash” the culture by repeatedly diluting, purging, and re-growing the mixture until the bad organisms are gone. This seems counter-intuitive, but here are the basic steps:

  1. Mix the culture thoroughly. Dump out all but 1 C
  2. Add an equivalent amount of warm water. Stir thoroughly.
  3. Dump out all but 1 C.
  4. Add 1 C flour and 3/4 C water. Stir well, then proof at 85°F for 6-12 hours.
  5. Repeat two or three times a day until the smell is gone and activity is absent for a day.

What happens is you thin out both the good and bad organisms. Because you’re keeping the culture in conditions ideal for the “good” organisms, but not ideal for the “bad” ones. Eventually you’ll reach a point where the “bad” ones can’t thrive and the good ones take over.

I repeated this three times a day, once at 8:00 am, again at 3:00 pm, and again at 9:00 p.m. After the first day, the activity level subsided quite a bit and the culture didn’t smell as bad. By day 3, activity was absent and the bad odor was gone. Same thing on day 4. By day 5, I had active fermentation, but with the expected sourdough smell. The good guys win!

The next step is to divide it in half, feed both jars with 1 C flour and 3/4 C water, wait an hour, then put one of them in the fridge for safe keeping. With the remaining batch, I was able to make two loaves of whole wheat bread and a batch of whole wheat pretzels. Both were wonderfully sour, though much heavier because whole wheat just works out that way.

I am pretty sure Sourdough II: The Wrath of Khan was not a true sourdough and any incidental leavening was the byproduct of “contaminants” fermenting in the starter mixture. The starter was never noticably sour, and eventually petered out on its own. Had I done the washing cycle, I would have ended up with a “Seattle Sourdough” mixture… eventually.

2 thoughts on “Sourdough III: The Search for Spock

  1. Hi, I, too, evidently contaminated a sourdo starter I purchased from Ed Wood. I followed the directions carefully, but in the morning, my starter was bubbling and doubling. I’ve read your comments about washing (I’ve done it twice today), but I’m still not convinced that the good San Francisco organisms will win out. In fact, how do we not know that it’s not just another sourdough organism? I would have no idea what SF starter should smell like, in any event. Thanks…

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