Full-fat yogurts generally freeze better than lower-fat ones, although they will separate when thawed. All yogurt should be defrosted slowly and given a good whisk before being used. Plain yogurt can be kept frozen for up to two months. Yogurt with added fruit, honey or flavoring freezes slightly better than the plain variety, and can be kept frozen for up to three months in the sealed carton it came in. Homemade flavored yogurt should be frozen in sturdy plastic containers with tightly fitting lids.