How to Start a Gluten-Free Sourdough Starter from Scratch

A gluten-free sourdough starter is a live culture of wild yeast and beneficial bacteria, fed with flour and water, that leavens bread naturally without commercial yeast. It is what gives sourdough its flavor, its digestibility, and its open crumb. If you have never maintained one before, the process is simpler than it sounds.

This guide covers how to build one from scratch using brown rice flour, which is what we use at Leaven & Love. Brown rice is one of the most reliable base flours for a gluten-free starter because it ferments predictably, has a mild flavor that does not overpower the bread, and produces a stable culture over time.

What you need

A clean glass jar, a kitchen scale, brown rice flour, and filtered or non-chlorinated water. Tap water with heavy chlorine can inhibit fermentation, so if your tap water smells strongly of chlorine, let it sit uncovered for an hour before using it or use filtered water instead.

Avoid commercial gluten-free flour blends. They often contain additives and starches that interfere with fermentation and make it difficult to build a reliable culture.

Day one

Combine 50 grams of brown rice flour with 50 grams of water at room temperature in your jar and stir thoroughly until no dry flour remains. Cover loosely — a cloth secured with a rubber band or a lid rested on top without sealing works well. You want airflow without exposing the starter to debris. Leave it at room temperature, ideally somewhere between 70°F and 78°F.

Days two through five

Once every 24 hours, discard all but 50 grams of your starter and feed it with 50 grams of fresh brown rice flour and 50 grams of water. Stir well and cover loosely again.
For the first two or three days, you may see very little activity. This is normal. Wild yeast takes time to establish. You may also notice some separation, a layer of liquid on top, or a mildly unpleasant smell during early fermentation. None of these are signs of failure. They are signs of microbial activity sorting itself out.

By day four or five, most starters begin showing consistent bubbles within 12 to 24 hours of feeding. The smell will shift from sharp or funky to something closer to tangy and slightly sweet.

How to know it is ready

A starter ready for baking will roughly double in size within 8 to 12 hours of feeding, smell pleasantly sour, and have visible bubbles throughout. A simple test is to drop a small spoonful into a glass of water — if it floats, there is enough gas production to leaven bread.

What goes wrong and why

The most common problem is no activity after several days. In most cases this is a temperature issue — cooler kitchens slow fermentation significantly. Moving the starter to a warmer spot, near an oven or on top of a refrigerator, often solves it.

The second most common problem is mold, which appears as fuzzy growth, usually green, white, or black, on the surface. If you see mold, discard the starter and begin again. Mold usually results from a jar that was not clean enough or a starter that sat too long between feedings.

Maintaining a starter long term

Once your starter is active, you have two options. If you bake regularly, keep it at room temperature and feed it daily. If you bake occasionally, store it in the refrigerator and feed it once a week, discarding 50 grams before each feeding and refreshing with equal parts flour and water.

A well-maintained brown rice starter can last indefinitely. Ours has been active for years.
If you want to take your starter directly into a finished loaf, the Gluten-Free Sourdough Masterclass walks through the complete baking process, from feeding your starter the night before to pulling a finished loaf from the oven.