With proper care and storage, you can typically use the starter culture for up to 3-4 batches of yogurt. u003cbr/u003eu003cbr/u003eHowever, it's important to monitor the consistency, texture, and taste of each batch of yogurt to ensure that the starter is still active and producing good results. u003cbr/u003eu003cbr/u003eIf you notice any changes in the quality of the yogurt or if it fails to set properly, it may be time to use a fresh batch of starter culture with store-bought yogurt.