Sourdough Starter Smells like Alcohol

If your sourdough starter smells like alcohol it is because the active bacteria have consumed the nutrients in the flour quickly and produced types of lactic acid that give off the distinct smell of alcohol. But don’t worry this is perfectly safe, easy to fix, and happens to the best of us! The starter at this point will be very acetic, hungry, and needs to be fed. (And there are lots of other reasons why starter can smell.)

Before we examine the remedies for your sourdough starter, let’s think a little bit about what is happening in your starter jar. The bacteria are breaking down the sugars and producing acid–which is exactly what fermentation is. In fermentation, carbohydrates (sugar) are broken down by microbial organisms (bacteria) and produce alcohol (acid). If this happens in large quantities, a thin layer of liquid can appear on top of your starter. This liquid is aptly nicknamed “hooch”! If hooch appears on your starter just pour it off or you can even just stir it back into your starter.

How to fix sourdough starter that smells like alcohol

To fix the smell of alcohol in your sourdough you can do the following:

  1. Increase the feeding frequency of your sourdough starter.
  2. Change your starter feedings from a whole grain flour to all purpose flour.
  3. Ensure the water in your starter feedings isn’t above 80°F or 27°C.
  4. Keep your sourdough starter temperature at or below 77°F or 25°C.

You don’t have to try these all at once. Instead, start with the first one and work your way down the list every couple of days if the smell of your sourdough starter doesn’t go back to normal.

Increase your sourdough starter feeding frequency

The alcoholic smell of your sourdough starter may be because your starter is hungry. Simply increase the feeding frequency and you will likely fix the alcohol problem within a day or two. If you normally feed your starter once a day, try increasing it to twice a day.

Change your starter feedings from whole grain to all purpose flour

Whole grain flour produces a more active starter and the bacteria will eat the nutrients in the flour quickly. This leads to a starter that gets hungrier, sooner, and you will experience the alcohol smell in your starter. Simply cut out the whole grain flour for a few days and try all-purpose flour and see if there’s a difference.

Use colder water (below 80°F or 27°C) to feed your sourdough starter

Hot water kills the yeast in your starter, however, most of the bacteria will continue to thrive. This leads to an imbalance between yeast and bacteria, and the alcohol smell will take over as the dominant scent of your sourdough starter. Simply ensure you are using room temperature water, or water below 80°F or 27°C. You want to avoid using very cold water as well because the starter will start to get sluggish and eat the nutrients in the flour too slowly.

After two or three feedings with the colder (but not cold!) water, the yeast population will start to re-establish itself and compete with the bacteria for food, which will naturally decrease the amount of alcohol-smelling acetic acid that is produced.

Keep your sourdough starter temperature between 70°F and 77°F or 20°C and 25°C

Sourdough starter kept at warmer temperatures than 77°F or 25°C will have overactive bacteria producing alcohol smells and underactive yeast that may even be dead and unable to balance the bacteria population

Also, note that colder temperatures will not kill the microbial environment of your starter, but they will make the bacteria and yeast much less active. This is why bakers who are out of town for a few days simply leave their starters in the fridge and take them out to revive them when they get back.

Can I use sourdough starter if it smells like alcohol?

There is no danger with using a starter that smells like alcohol, however, the bread you bake will likely not have a satisfactory oven spring. In other words, your sourdough won’t rise properly. This is because an alcohol-smelling starter indicates a hungry starter that needs to be fed. You want to bake with a properly fed, well-nourished starter that will create the air pockets in your bake required to create a nice rise.

Sourdough starter smells like beer or wine

Sourdough starter can smell like beer or wine simply because it’s hungry and the bacteria produce excessive acetic acid. Specifically, different bacteria produce different lactic acids. Some of these acids smell like alcohol, and within those, some produce a beer-like smell, and others produce a wine-like smell.

Does sourdough contain alcohol?

Sourdough starter contains bacteria and yeast that break down carbohydrates into acid, which is essentially alcohol. In fact, in some cases, a thin layer of liquid appears during this fermentation process and bakers call it the starter “hooch.”

However, through the baking process, all of the alcohol is effectively evaporated. This liquid vapor expanding inside of the bread as it heats up is what gives the oven spring or rise of the sourdough bread. In addition, all of the yeast and bacteria in the starter are killed off during baking as they cannot live at such high temperatures.