Sourdough Starter Liquid: What Is Hooch and What Do You Do With It?

That layer of liquid sitting on top of your sourdough starter can look alarming, especially when you're new to sourdough. Is it ruined? Did something go wrong? Take a breath: it's called hooch, it's completely normal, and it's actually a helpful signal.

Sourdough starter liquid is simply the by-product of a hungry starter. It shows up when the starter has finished all the food you gave it and the microbes keep fermenting, pushing out a veiled layer of alcohol and water. It's the starter's way of asking for breakfast.

Why hooch forms

Everything in your starter — the wild yeast and lactic-acid bacteria — feeds on the flour and water you give them. When they've eaten it all, fermentation continues and produces alcohol as a by-product. That alcohol, combined with water drawn to the surface, becomes the liquid you see on top.

So hooch isn't a sign of spoilage at all. It's a sign of hunger. A well-fed starter barely produces any; a starter left waiting too long produces more, and it grows darker the longer it waits.

What to do with hooch

Ask any baker and you'll get two honest answers, because both are right — it just depends on the situation.

For a normal starter you feed regularly: stir it back in. Hooch is part of the starter's hydration, and it also brings a pleasant tang to your bread. Mixing it in before you discard and feed keeps the starter balanced and adds a little extra character to the loaf.

For a long-neglected fridge starter: pour it off. If your starter has been in the fridge for weeks and the hooch has gone very dark, pour it off before you feed. This is the reviving an old starter situation — a dark, thick hooch layer just isn't the same flavor contribution as fresh, lightly-formed hooch.

Color is your gauge

Hooch tells you how hungry the starter is, and its color is the dial:

• Clear or slightly cloudy — a young, recently-fed starter
• Tan to yellow — starter that's been waiting a while
• Grey to dark brown — a badly neglected, fridge-forgotten starter

The darker the hooch, the longer the starter has gone without food — and the more urgently it needs a feed.

How to stop hooch from forming

If your starter is constantly forming hooch, it's eating faster than you're feeding it. Three fixes, in order of impact:

1. Feed more often — every 12 hours instead of 24.
2. Move it somewhere cooler — warmth speeds up fermentation, so a cooler spot makes the food last longer.
3. Feed a bigger ratio — going from 1:1:1 to 1:2:2 gives the starter double the food to work through.

A healthy, regularly fed starter should be thick like warm peanut butter with barely a drop of hooch. When that's true, the starter feeding guide will help keep it that way — and if you ever spot fuzzy mold instead of liquid, that's a different story (the moldy starter guide has the details).