Cultured Buttermilk Troubleshooting FAQ - Cultures for Health

Whether this is your first time culturing buttermilk at home or you have years of experience culturing dairy, we're here to help you troubleshoot whatever culturing issues come your way. Below you'll find common issues you may encounter while culturing buttermilk with tips on how to correct them to keep your starter healthy and homemade buttermilk delicious.


Q. My first batch of buttermilk (using the heirloom starter) has been culturing for the maximum number of hours but is still the consistency of milk. What should I do?

A. At times, the activation batch will not set up as expected. While it isn’t the most desirable outcome, it should only happen with the first batch. Put a tight lid on the container and store in the refrigerator for at least 6 hours. Following the instructions for culturing, use a portion of the activation batch to culture the next batch. Subsequent batches should set up well. Any milk remaining from the activation batch is cultured and can be used in smoothies.

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Q. My buttermilk separated into solid and liquid layers (curds and whey). What happened?

A. Separation is usually an indication of overculturing or culturing at too warm of a temperature. Adjust the culturing time and check the culturing temperature to make sure it is within the appropriate range.


Q. My buttermilk seems to have set, but there's a little clear liquid (whey) floating on the top and the sides. Is this okay?

A. Some whey formation is normal when culturing. Drain the whey for a slightly thicker buttermilk, or stir it in for a thinner buttermilk.


Q. My buttermilk looks lumpy and curdled. What did I do wrong?

A. Sometimes overculturing (too long or too warm) can cause the buttermilk to curdle or become lumpy before it separates fully. To make a smooth consistency, simply whisk it. (Remove some of the whey if you like, or stir it back in.) Check the culturing temperature to make sure it is within range: 70°-77°F for the heirloom culture or 74º-77ºF for the directset culture.

A culture that is too old can also cause this problem. We recommend reculturing heirloom cultures within 7 days, for best results.


Q. Why is my buttermilk bitter?

A. Using too much starter can crowd the bacteria, creating a thin consistency and a bitter flavor.Overcultured buttermilk may also taste bitter. Check the culturing temperature to verify it is within the appropriate range.


Q. Why is my raw milk buttermilk runny?

A. Heating denatures the milk proteins, which allows the milk to coagulate and thicken more. Raw milk has not been heated; therefore, the proteins remain intact and will not coagulate the same way and cannot create a buttermilk that is as thick.


Q. Why is my buttermilk too sour or not sour enough?

A. Temperatures on the higher end of the temperature range and longer culture times will yield a more sour flavor. To achieve a less sour flavor, culture at the lower end of the range or for a shorter period of time.


Q. Why is my buttermilk foamy (or stringy) and yeasty-smelling?

A. This issue is generally caused by cross contamination from yeast, which can come from a sourdough starter culturing too closely, or wild natural yeast that has come in contact with the buttermilk. To avoid this problem, clean all equipment, utensils, counters and other materials used in the buttermilk-making process. Keep any other fermenting foods separated by several feet.


Q. Why is my buttermilk moldy?

A. Mold is rare in buttermilk making. Make sure all equipment, utensils, counters and other materials are clean. Do not culture near garbage cans or compost bins. Use the freshest milk. Make sure to store direct-set cultures in the freezer to keep them fresh and reculture heirloom cultures at least every 7 days. If mold appears, discard everything and begin fresh with a new starter.