Sourdough and Grain Fermentation Without Commercial Yeast

Creating a Starter from Scratch

You don't add yeast. You create conditions where the yeast already on the flour can flourish.

What you need:

• Whole wheat or whole rye flour (unbleached)
• Non-chlorinated water (filtered tap water, or tap water left out for an hour to off-gas chlorine)
• A clean glass jar
• A kitchen scale

Day 1: Mix 50g whole wheat flour + 50g water (room temperature) in a clean jar. Stir vigorously to incorporate air. Cover loosely (cloth, loose lid, or plastic wrap with a hole). Leave at room temperature (70-75°F is ideal).

Days 2-4: Discard all but 50g of the starter. Add 50g flour + 50g water. Stir and cover. Repeat every 24 hours.

You may see bubbles in the first day or two from bacteria other than yeast. The starter may then go quiet. This is normal. The beneficial wild yeast has not fully established yet.

Days 5-10: Continue daily feedings. The starter should begin rising noticeably after each feeding, then falling as the yeast exhausts the available sugars. When it reliably doubles within 4-8 hours of a feeding and smells pleasantly sour (not like acetone or vomit), it's ready to use for baking.

The float test: Drop a small amount of starter into a glass of water. A starter that floats has produced enough gas to indicate active yeast and is ready for baking.

Maintaining the Starter

A healthy starter is simple to maintain. The choice is frequency of feeding versus storage method.

Room Temperature Maintenance

Feed daily (or twice daily in hot weather). Keep 50-100g of starter and feed with equal weights of flour and water (1:1:1 ratio by weight — 50g starter : 50g flour : 50g water).

This produces a lot of discard. Use the discard in pancakes, crackers, flatbreads, or muffins. Never waste it.

Refrigerator Storage

For less frequent baking, store in the refrigerator and feed weekly. Cold dramatically slows fermentation — a refrigerated starter can survive 2-3 weeks without feeding, though quality degrades.

To use a refrigerated starter: Take it out the night before baking. Feed it. Let it reach room temperature and become active (4-8 hours). Use in your recipe.

The Feeding Ratio

The ratio determines how long the starter stays active between feedings.

• 1:1:1 (equal parts starter, flour, water) — starter peaks in 4-8 hours at room temperature, daily feeding required
• 1:5:5 (1 part starter, 5 parts each flour and water) — starter peaks in 12-16 hours, less frequent feeding possible
• 1:10:10 — used for very slow, cool fermentation or when you won't bake for several days

For survival situations, a 1:1:1 ratio fed daily is the simplest approach.

Basic Sourdough Bread (No Equipment)

No stand mixer, no Dutch oven, no precise oven required. This is the simplest version.

Ingredients:

• 200g active starter (fed 4-8 hours ago, doubled, still active)
• 300g water (warm, not hot)
• 500g all-purpose flour (or whole wheat)
• 10g salt (1.5 teaspoons)

Process:

1. Mix starter and water in a large bowl until combined.
2. Add flour and salt. Mix until no dry flour remains. The dough will be shaggy.
3. Cover and rest 30 minutes.
4. Stretch and fold: Wet your hand, grab one side of the dough, stretch it up and fold it over the center. Rotate the bowl 90 degrees and repeat. 4 folds = 1 set. Do 4 sets of stretch-and-folds, spaced 30 minutes apart.
5. After the last fold, cover and leave at room temperature for 4-8 hours (bulk fermentation) until the dough has grown 50-75% and looks airy.
6. Gently shape into a round on a lightly floured surface.
7. Place in a floured bowl or lined container, seam up. Cover and refrigerate overnight, or proceed to baking after 1 hour.
8. Bake in the hottest oven available: ideally 450-500°F in a covered pot (Dutch oven, cast iron with foil cover) for 20 minutes covered, then 20-25 minutes uncovered until deep brown.

Without a covered pot, bake at 400°F in any pan. Place a pan of boiling water in the bottom of the oven to create steam, which helps oven spring and crust formation.

Sourdough for Non-Bread Applications

Fermented Flatbreads

In a grid-down scenario without a real oven, flatbreads cooked on a cast iron pan or stone are more practical than loaves.

Mix starter (100g) with enough flour to form a pliable, slightly sticky dough. Add salt. Let rest and ferment for 2-4 hours. Pull off small portions, roll thin, and cook directly on a dry heated surface 2-3 minutes per side until cooked through and lightly charred.

This works with any flour — wheat, corn, even acorn flour.

Fermented Porridge (Injera-Style)

Thin the starter heavily with water (1 part starter to 3-4 parts water). Add flour to thin batter consistency. Ferment 12-24 hours until bubbly. Cook on a flat surface as large thin pancakes. The acidic flavor from fermentation is intense and characteristic.

This is essentially injera, the Ethiopian flatbread, and it's one of the most efficient uses of grain when fuel is limited — thin and fast to cook.

Sourdough Crackers (Discard Use)

Mix discard with a small amount of flour, fat (any kind), and salt to form a stiff dough. Roll very thin. Bake at 350°F for 15-20 minutes. These last several weeks in a sealed container and use up discard that would otherwise be wasted.

Drying Starter for Long-Term Storage

Spread a thin layer of active, bubbly starter on a non-stick surface: parchment paper, silicone mat, or the back of a clean baking sheet.

Let it dry at room temperature, or in a dehydrator set to the lowest setting (below 95°F). High heat kills the yeast — this is the one temperature rule that matters. A dehydrator at 115°F is too hot.

Drying takes 12-24 hours at room temperature. When completely dry and brittle, break or crumble the dried starter into flakes. Store in a sealed jar or vacuum-sealed bag with an oxygen absorber. It keeps for 1-2 years in a cool, dark location.

Rehydrating: Combine 1 tablespoon dried starter flakes with 50g warm water. Let soak 1 hour. Add 50g flour. Stir. Cover. Repeat feedings daily for 3-5 days until active again.

Troubleshooting

Liquid on top (hooch): Grayish liquid that separates to the top of the starter is alcohol produced by yeast. It means the starter is hungry. Stir it in or pour it off and feed immediately. Gray hooch = unfed starter. Not ruined.

Pink or orange streaks: Contamination by non-beneficial bacteria. Discard and start over.

Not rising after 2 weeks: Try: switching to whole rye flour (highest yeast population), warmer fermentation location, different water (chlorine in tap water inhibits fermentation), or discard more aggressively before feeding.

Vinegary/harsh smell: Over-fermented or under-fed. Decrease feeding interval or increase hydration slightly. Healthy starters smell pleasantly sour, like yogurt or mild vinegar — not harsh or chemical.

Acetone or nail polish smell: Very hungry starter. Feed immediately. Usually corrects with one or two feedings.