You should resist the temptation of stocking up on mayo, even though your grocery store is having a killer sale, because freezing these extra jars will do no one any favors. When mayo thaws after being frozen, it will separate and take on a clumpy texture.
Leftover gravy is a very problematic thing to have in your kitchen. Although it tastes delicious, it’s only able to last at the very most two days in your fridge. To complicate matters, cream and milk-based gravies won’t hold up nicely in the freezer, as they’ll separate and turn lumpy when thawed.
Frosting that is egg white-based is not meant to be kept in the freezer, as it will lose its fluffiness and start to “weep,” also known as emitting liquid, once it thaws. The same should be applied to meringue, which is also derives from egg whites.
There are cooks who believe freezing extra garlic before the cloves start sprouting is okay, stating that one should coat whole cloves or pureed, peeled cloves in a neutral-flavored oil before freezing. However, the National Center for Home Food Preservation warns against this, as garlic tends to get too strong and bitter once it’s frozen.
There are also certain spices that you should avoid tossing into the freezer. Onion and paprika can have an altered flavor, celery seasoning will get stronger, and curry can develop a musty off-flavor, per the National Center for Home Food Preservation. Similar to garlic, green pepper, cloves, and imitation vanilla can become strong and bitter when frozen.Related: 4 Mistakes When Cooking Frozen Vegetables