Ingredients

• 1 cup instant potato flakes (plain; unsalted, unflavored)
• 8 teaspoons cornstarch
• 1 teaspoon sugar
• A trace of active dry baker’s yeast (just a fraction of a pinch)
• 1 teaspoon ground cinnamon

Tip: Make the dry base ahead and store in a sealed container until needed.

Directions

1. Combine potato flakes, cornstarch, sugar, and cinnamon in a bowl to create the dry base.
2. For a new culture, spoon the mix into your container. If unsure, aim for a layer about 2–3 cm deep.
3. Hydrate with roughly the same volume of water as the dry mix in the container—moist, not soupy.
4. Dust the surface with a tiny amount of baker’s yeast—only a fraction of a pinch to start fermentation.
5. Add flies immediately to establish the culture.