Dark Liquid on Top of Sourdough Starter — What Is Hooch and Is Your Starter Dead?

Quick Answer

The dark liquid on top of your sourdough starter is called hooch — it is alcohol produced by the yeast as a byproduct of fermentation. Hooch forms when the starter has consumed all its available food (flour) and is essentially starving. Your starter is not dead. Stir the hooch back in or pour it off, feed the starter with fresh flour and water, and it will recover within one to three feedings.

Finding a layer of murky brown or greyish liquid floating on your starter can be alarming, especially if you have been nurturing it for weeks. Take a breath. This is one of the most common sourdough situations and one of the easiest to fix.

What Hooch Actually Is

Your sourdough starter is a living colony of wild yeast and lactic acid bacteria. The yeast consume sugars in the flour and produce carbon dioxide (the bubbles that make bread rise) and ethanol (alcohol). The bacteria produce lactic acid and acetic acid, which give sourdough its sour flavor.

When the yeast have eaten through all the available sugars in the flour, they continue to produce alcohol but the CO2 production slows. That alcohol, being less dense than the batter, rises to the top. Mixed with water and waste products, it forms the liquid you see — hooch.

The color of hooch varies:

Clear to light yellow: The starter was only mildly underfed. Quick recovery.
Grey or light brown: The starter has been hungry for a day or two. Still fine.
Dark brown or almost black: The starter has been unfed for several days or longer. It may need several feedings to bounce back, but it is very likely still alive.

The color darkens because the oxidation of the alcohol and organic acids increases over time, and because the bacteria produce more acetic acid when stressed, which has a darker color when concentrated.

What to Do About It

You have two choices with the hooch itself:

Stir it back in. This adds the accumulated alcohol and acids back into the starter. Your next loaf may taste more sour or have a slight alcohol tang. Some bakers prefer this for a stronger sour flavor.

Pour it off. This discards the excess acid and alcohol. Your starter will be less sour and the next loaf will have a milder flavor. If the hooch smells strongly of alcohol or acetone, pouring it off is usually the better choice.

After dealing with the hooch:

If your starter smells like nail polish remover (acetone), that is acetic acid dominance and means it has been hungry for a while. This smell should diminish after one or two feedings. If your sourdough bread is not rising well even after reviving the starter, it may need a few more feeding cycles to build up enough yeast activity for a strong rise.

When Is a Starter Actually Dead?

Sourdough starters are remarkably resilient. A starter that has been neglected in the fridge for months — even with a thick layer of hooch and a funky smell — can almost always be revived with consistent feeding over a few days.

A starter is only truly dead if:

It has visible fuzzy mold (pink, green, black, or white fuzzy growth). Mold is a different organism from the yeast and bacteria in your starter. If you see fuzzy mold, discard the starter and start fresh. Do not try to scrape off the mold and save the rest — mold produces invisible root structures (hyphae) that penetrate through the entire culture.
It smells putrid — not just sour or boozy, but genuinely rotten, like garbage. A healthy starter smells yeasty, tangy, or like overripe fruit. A dead one smells like decay. This is rare and usually only happens if the starter was contaminated with harmful bacteria.
It shows zero activity after 5-6 feeding cycles at room temperature. If you have been feeding consistently for several days and there are absolutely no bubbles, no rise, and no sour smell developing, the yeast colony may have been killed off (extreme heat exposure is the usual cause — yeast dies above 120°F/49°C).

Tip

A starter that has been in the refrigerator for a long time may take 3-5 feedings at room temperature to wake up. Cold slows the organisms dramatically but does not kill them. Do not assume it is dead after just one or two feedings. Patience matters — the same principle applies to bread machine dough that does not rise because the yeast needs time and the right conditions to become active.

Preventing Hooch

Hooch is simply the starter telling you it is hungry. Prevent it by feeding on schedule:

Room temperature starter: Feed every 12 hours (twice daily) if your kitchen is warm (75°F+), or every 24 hours if cooler.
Refrigerated starter: Feed at least once a week. Take it out, discard, feed, let it sit at room temperature for 2-4 hours to activate, then return to the fridge.
Adjust the ratio. If hooch develops between scheduled feedings, your starter is consuming its food too fast. Try a 1:2:2 or 1:3:3 ratio (starter:flour:water) instead of 1:1:1. More flour means more food and a longer time before the starter gets hungry.

If you bake infrequently and want to keep maintenance minimal, the fridge is your friend. A weekly feeding is usually enough to keep a refrigerated starter healthy indefinitely.