Cold call: A guide to freezing leftovers, via Swetha Sivakumar

The freezer can be a great friend to the overenthusiastic host, the energised urban farmer. It extends shelf life while preserving nutrients, as long as it’s done right. Just remember that there are three enemies of frozen food: time, air and enzymes. Reduce exposure to them all for best results.

TimeFreeze foods as rapidly as you can. The slower the freezing process, the more ice crystals form in food. The larger the crystals, the more the internal cell damage. Finally, when you thaw the food, it will be a soggy mess.

To avoid this, do not freeze foods in tall, deep containers. Instead, place the food in a thick, sealable plastic bag and lay it flat to allow for quick freezing. Do not stuff your freezer with too many warm items at a time. Allow the cold air to circulate well.

AirIf you expose the frozen food to directly to the cold air, it will suffer freezer burn. Just as winter weather gives you dry skin, the cold, dry air of the freezer sucks up moisture from the food. Select thick plastic bags to store foods in. After filling it, squeeze out as much air as possible, to prevent exposure.

Enzymes If you do not deactivate the enzymes in raw food, they will go bad over time, and will emerge rotten as they thaw. Enzymes are found in raw fruits and vegetables, not in cooked foods. Blanch your raw fruits and vegetables for 3 minutes. Allow to dry, then freeze. This will allow them to retain their bright colours and flavours for much longer.