Abstract

Yesterday we hopped on a bus and drove to a farm near Tuscania, where we’ll stay for the week, learning about sustainable farming (and picking olives).

I decided to try an experiment with the effect of kneading bread on fermentation time. I wanted to see the difference between two breads, prepared with the same recipe, in which:

  • one loaf was left un-kneaded and fermented at ambient temperature overnight, in a bowl covered with plastic wrap;
  • one loaf was kneaded and left in the fridge overnight, in a bowl lined and covered with a dish towel.

Methodology

Both of the loaves for this experiment were prepared based on the proportions from Lazy Sourdough. However, we used different types of flour, which in hindsight likely confounded the results. We also included some additives in each loaf, which difffered slightly. The ingredients, where they differ from the basic recipe, are given below for each loaf:

  • Un-kneaded loaf: 2 cups white flour, 1/2 cup rye flour, 1/2 cup whole wheat flour, raisins;
  • Kneaded loaf: 2 cups white flour, 1/2 cup buckwheat flour, 1/2 cup whole wheat flour, raisins, hazelnuts.

The kneaded loaf was hand-kneaded for about 15 minutes, after the nuts were incorporated. The dough was quite wet and sticky. The nuts also made it difficult to knead, since they seemed to break gluten chains and hinder its ability to be stretched.

Results

Un-Kneaded Loaf

This loaf took longer than expected to ferment, likely due to the lower temperature in the kitchen at night. But when we baked it approximately 14 hours after mixing, it turned out as expected.

Kneaded Loaf

When the loaf came out of the fridge in the morning, it didn’t appear to have risen at all. The dough was tough and the finger-dent test left a permanent indent. Initially I thought the stiffness of the dough was due to the temperature, but a few hours later, the texture remained and the dough still had not risen. I have a few theories for why this may have occurred:

  • The dough was not kneaded sufficiently, so when it was left to ferment, the gluten didn’t expand.
  • There was no period of room-temperature fermentation, so the yeast worked too slowly. However, this wouldn’t explain why the dough didn’t recover on its own after being removed from the fridge and left out.
  • There was insufficient sourdough starter in the recipe, or the starter was not active enough. Though the kneaded and un-kneaded bread used the same amount of starter, it’s possible that being placed immediately back into the fridge slowed down the yeast too much.

I was able to resurrect the kneaded loaf by kneading in more sourdough starter, reforming a loaf and leaving it to proof for another few hours. However, the dough was still quite sticky, so I think I may have added too much water initially.

Conclusion

There are too many confounding factors in this experiment to draw a definitive conclusion. I have given a few potential reasons above, but I can’t say with any certainty which one was the largest factor.