October 12, 2023 - 6:00am
New study on sourdough cultures
Erin McKenney, the researcher behind the Fermentology presentations a few years back has just published new results on sourdough cultures using a number of different flours. The paper is summarized and linked here. You have to love inquiring minds…
Share
[sorry for duplicate comment I just noticed this article was posted earlier] I find it incredible that they didn’t mention in the full article (or even record?) the ambient room temperature. Given the variability in temps that bakers use it would be ver helpful to know that, and it would have been even better if they had varied the temperature using a blocking design. Still, very interesting results.
They mention that they used King Arthur's recipe for starter development where ("warm") room temperature is defined as 70F, so we can assume that it was the same in their experiment.
Although I agree that it is strange that they did not track the average, the extremes over 2 week period, and day-night fluctuations. In this study, the researchers partnered with middle school teachers, four teachers from four different schools, each creating 10 starters from scratch, so their room temperatures are really a mystery.
They also used distilled water which is not what most home bakers use in their starters.
What I find interesting in this study, that at "warm room temperature" (70F) KAB recipe produced a stable microbial community only between days 10-14, not in 5-7 days as KAB original recipe suggests (where they only track volume and bubbles to see when the starter is ready for baking).
A temperature of 70F seems low to me. I would always use 77F for starter creation - perhaps why these starters took a while to reach usability?
I also wondered about using distilled water - perhaps that could lead to some calcium deficiency, depending on the flour used?
Lance
What I find interesting in this study, that at "warm room temperature" (70F) KAB recipe produced a stable microbial community only between days 10-14, not in 5-7 days
It's hard to know if times beyond 10 days really had a practical effect. They don't report or analyze the experimental variation, and for the most part the post-10 day changes weren't large. They might easily have been nearly non-existent.
Another potential source of noise (measurement error) was taking 1 mL of starter out each day for testing. That amount would be hard to measure with a viscous substance like a starter, even a watery one.