From preserving and conservation: Freezing

Before freezers or refrigerators found their way into our households, there were cold storage houses where people could rent and share the icy pantries. And even longer ago, people used natural ice to preserve their food. Freezing food is simply very convenient. Fruits and vegetables, as well as meat and fish, can stay fresh for several months when frozen, and vitamins and flavors are largely preserved.

How it works: some icy theory

Frozen foods have a long shelf life because the bacteria and molds that cause them to spoil cannot survive at such low temperatures. In drying and dehydrating, they are thoroughly spoiled by dehydration; in canning, as well as in the production of jams or juices and syrups, the heat takes care of that. Preservation therefore always revolves around the question of how to make life as difficult as possible for the small microorganisms.

During freezing, the water contained in the food turns into ice. The shelf life of different foods can vary considerably. Unfortunately, the information on this also varies greatly depending on the source, as it always depends on the quantities that are frozen, whether larger or smaller pieces are frozen, whether the food is raw or cooked, how full the freezer compartment is, which model is used… because of these many uncertain factors, there is only one thing left to do: try it out for yourself and freeze food for a shorter period of time and use it up more quickly than forgetting it for months in the farthest icy corner. Roughly speaking, vegetables, fruit, herbs and mushrooms can be kept for at least six months and a maximum of one year.

Tips and tricks for freezing

Freezing changes the character:

Many foods have a glassy appearance after thawing, but are still edible. Due to the damage to the cells, the appearance and consistency are of course not comparable with the fresh state. Thawed fruits and vegetables are therefore well suited for use in all kinds of desserts or cakes, soups or casseroles. The industry manages it more crisply: by freezing at extremely low temperatures, more cell walls remain intact and the food is more likely to retain its shape.

There are a few foods that should not be frozen:

• Cucumbers: they are so watery that only slush would remain after thawing, similarly with watermelons (although these can still go into a delicious smoothie).
• Lettuce: the fine leaf structure is very much damaged by the freezing of the water in the cells. You may have observed what happens to a forgotten lettuce in the bed after the first frost: it becomes glassy and slimy when temperatures rise again.
• Raw potatoes: if you’re not a fan of glassy, slimy potatoes with a strange sweet taste, it’s better not to freeze potatoes raw.

The right preparation – freeze raw or blanch briefly:

Some foods can be frozen raw without any problems, including fresh herbs, zucchini, squash and mushrooms.

However, zucchini pieces or slices can be blanched briefly beforehand. It is also possible to cut them into small pieces and salt them. This causes them to lose a lot of water, which can be poured off before freezing.

Legumes, cabbage and carrots should be blanched first, that is, cooked for a few minutes and then rinsed under cold water. This keeps them crisper after thawing and also allows them to be frozen for a longer period of time. It also preserves the flavor better.

A good example of this is tomatoes, which can be frozen whole or chopped raw, but after thawing are then very mushy and hardly taste of anything. It is more practical to cook a delicious sauce from them beforehand and freeze it.

Freeze as small quantities as possible and pack flat:

Temperatures in home freezers and cabinets are freezing, but it still takes time for something to really freeze through and through. Maybe you’ve made ice cubes that looked done on the outside, but were still liquid on the inside. The faster a product freezes through, the safer it is from bacteria. It therefore makes sense to chop up some foods first, not to pack freezer bags too full or to use smaller containers for freezing.

For the perfect dosage, spread it out first, then put it in the bag:

This tip applies mostly to berries. You can theoretically freeze a freezer bag full of raspberries, but it will turn into one thing: a big block of frozen raspberry slush. The delicate fruit will be crushed and later you’ll have to defrost the whole bag at once. It is more practical to first freeze the berries spread flat on a tray or board for a few hours before you pack the hard fruit into bags or cans. From there you can take them out one by one.

This procedure is also very practical for diced onions or chopped herbs. Often you only need a small amount for cooking.

Labeling for a better overview:

Even if you think that you will definitely remember when the applesauce was frozen, it is still easy to lose track of it. Freezer bags should therefore always be labeled with a waterproof pen, and small stickers on cans or other containers help. It is practical to write the approximate best-before date on the label.

That way everything stays safe and edible:

Check your supplies regularly and sort out the things that have been frozen for too long. If freezer bags or other containers were not properly sealed, freezer burn can occur. This is when dry spots form on the food and it is no longer edible, but this mainly affects meat and fish.

Once defrosted, food can spoil quickly, as the cells destroyed by the frost are gateways for bacteria and the like. Therefore, consume them quickly. If you want to freeze them again, be sure to cook them completely beforehand.