A Customer Asked: Does it matter how much starter culture I use to make cheese or yogurt? Will it hurt if if I use too much? Sometimes I use the amount called for, and it doesn’t work. Should I add more?

Jerri’s Answer: Great question! You should always use the amount of starter culture specified in the recipe.

Starter culture contains the lacto-bacteria that grows when the milk is warmed. The culture helps create the acidic environment necessary for cheese curds to form, and for yogurt to set up properly. If you use too much culture, the milk will become too acidic and kill off the lacto-bacteria. And when the environment is too acidic, cheese curds won’t form and yogurt won’t set up as it should.

If curds didn’t form as expected even though you added the correct amount of rennet and starter culture, it’s often because there was problem with the milk. The milk might have come from a cow that had a sub-clinical infection. When undesirable micro-organisms are present in the milk, they can interfere with the process and prevent the rennet and starter culture from working. As a result, curds don’t form properly when making cheese. Similarly, when making yogurt, the starter culture is inhibited from working as it should, and your yogurt doesn’t set up to a thick consistency.

In these situations, it’s best to find a different source of milk and try again.