You should know exactly what you freeze
First of all, you should try to avoid freezing foods without their label and other significant details. If you find something that has no label, you should not eat or cook that, because your health may be adversely affected even though they were initially frozen. So, you should toss out any unidentifiable foods.
How could you do that? Well, you can use a permanent marker to write on a piece of paper the date of freezing and expiration of that product.
“Label and date everything you freeze so you’re sure what it is and how old it is,” Lam says.