Milk
Unfortunately, milk stored in the freezer can separate into chunks and watery parts when thawed. It will be safe to eat, but it’s not exactly the best consistency for adding to your morning cereal or coffee.
Potatoes
Potatoes have a high water content, so after being stored in the freezer, you could be left with a mushy, soft potato. If you’re cooking a meal with potatoes and you’re hoping to freeze the leftovers go for it. Cooked potatoes won’t be as mushy as if you froze them raw. The texture change won’t matter too much in cooked casseroles or stews.
Fried foods
Sorry, leftover mozzarella sticks! Foods that were fried will lose all their crunch if you put the leftovers into the freeze—and no one wants soft, mushy fried foods. If you’re planning to make a batch of home-cooked chicken nuggets to store in the freezer, you’re better off skipping the fryer and opt to bake the meal in the oven first.
Eggs still in their shell
Putting eggs that are still in the shell into the freezer is a big no-no. The water content inside the egg expands when frozen, which can cause the outer shell to crack and be vulnerable to bacteria. If you want to freeze your eggs, always take them out of the shell, beat until they’re well blended and store in an airtight container with a label.
Soft cheeses
Storing soft cheeses in the freezer will yield a similar result to storing milk there. When it comes time to eat them, you’ll be left with watery lumps, which often ruins the texture of foods like cream cheese, sour cream, and ricotta.
Raw veggies and fruits
Any vegetable or fruit that has a high water concentration, like celery, cucumber, salad greens, and watermelon will not survive the freezer because the water inside quickly forms ice crystals. What that means is when it comes time to thaw them, you’ll be left with a mushy, inedible mess.
Crumb-topped meals or desserts
If you have an amazing baked macaroni and cheese meal that’s topped with the perfect crispy crumble, you don’t want to stash it in the freezer. Much like the fate of the fried foods, when crumb-topped meals and deserts meet the cold temperatures of the freezer, you’ll be left with soggy, soft mush.
Meat that you’ve already defrosted
If you pulled the pork chops out of the freezer to cook for dinner, never re-freeze the leftovers. Frozen and thawed foods can attract potentially harmful bacteria faster than meat that hasn’t been in the freezer. Your best bet is to cook the meat to the proper temperature and eat it or pop it back in the freezer after you’ve cooked out all the potential bacteria.
Yogurt
Health-wise, there's nothing wrong with popping a tub of yogurt in the freezer before it expires. The good news is, freezing yogurt doesn't kill its healthy live and active cultures, but the bad news is that when it's thawed, the texture will lose its creaminess and become grainy. Also, if you were hoping to create a freezer-ready treat similar to fro-yo, you'll be disappointed. Regular yogurt has more water than the ones you'd buy frozen, leaving an icy block when you try to give yourself a scoop.
Pasta
You won't get sick from eating thawed leftover pasta, but you might not want to eat it. Most pasta will get mushy when you take it out of the freezer, though you might have luck with noodles that are cooked al dente.