Wild yeasts

Homo naledi ate dirt. A study summarized in Science News (9/16/17) examined the 300,000-year-old (plus or minus 35,000 years) teeth of this South African hominid and found an unusual amount of chipping. The damage, the researchers suggested, was consistent with eating nuts, seeds, and grit-covered roots and tubers.

This was one of those news tidbits that captured my imagination. H. naledi dug food out of the ground and ate it. And why wouldn’t they? In parts of South Africa, they would be hard pressed to find enough water to drink, let alone wash their food. What fascinated me was the thought that somewhere along the line in human evolution, someone said, “Hey! Let’s take these tubers to the river and rinse off the grit!” Someone had to invent food washing.

Someone invented cooking. Much later, there was farming. Grains would have been cooked whole at first, until someone got the idea of crushing them with stones. I imagine there was not a whole lot of intentionality in these developments. Certainly folklore suggests many happy accidents. The milk stored in a calf’s stomach changed to cheese. The cheese forgotten in a cave changed to Roquefort. The food may have been considered spoiled, but it was eaten anyway. There may have been nothing else.

Flour mixed with water and left out started to ferment. It got baked anyway because there was no food to waste. The bread was no longer flat! It could be that the first person to try it said, “Man! This bread tastes just like an old, wet dog!”

I am, of course, building up to my own recent experiment with sourdough. As the recipe promised, the smell did improve. A few days after the old, wet dog smell, the starter underwent the transformation described in the directions. It doubled in volume rapidly and took on a boozy, vinegary odor.

Starter, Wednesday evening

Starter, Thursday evening

Close up of the air pockets in the bubbly starter

 I was not the only one to notice. One morning, there were two fruit flies under the plastic wrap. Fruit flies? In November? Where did they come from? This is the sort of thing that made people believe in spontaneous generation.

The starter seemed ready to go by Sunday. There is nothing fast about sourdough. First, the starter has to be fed and sit at room temperature for 5 hours. Then it has to be refrigerated for 12 hours. The starter is thinned with water and mixed with flour and salt. And it sits for 12 hours longer. Due to a math error, the starter was due to be made into dough at 1:00 Monday morning. Oh well. These days, I’m up anyhow. I measured everything before I went to bed so I could throw it together quickly and get back to sleep.

When I got home from work Monday afternoon, I punched it down and put it in a parchment-lined Dutch oven for the final rise. It smelled unpleasantly sour, and I feared my two weeks of effort was a bust. Still, like my ancient ancestors, I pressed on, not wanting to waste. I often make a similar recipe in which I do the final rise in a linen towel and tip it into a pre-heated Dutch oven. This time, the cold dough and Dutch oven go into the cold oven, and everything heats up together. I was skeptical, but it came out great. It tasted good too! It was only mildly sour, and had a great chewy texture.

The final product--the white spots are flour

 I’m sold! I will keep my wild yeasts and lactobacilli, feeding them every week. Maybe I can find some other things to make with it. 

Here we are at Thanksgiving already. As we gather at the table, we are thankful for good food, good company, and good wine. This year, I’m going to remember to be thankful that I don’t have to eat dirt.