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By November 15, 2013 0 Comments Read More →

How to Freeze Food

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In 2011 Home Farmer commissioned Piers Warren to write a series of articles on the different methods for storing your fruit and veg. Here Piers Warren explores different methods for storage, starting with the deep freeze.

Growing fruit and vegetables in our climate often means much of the produce will become ready for consumption at the same time – in the summer and autumn – and most of it will go to waste without proper storage. Freezing is a method that has relatively recently revolutionised the storage of fruit and vegetables for many households. It’s also quick, easy, and very effective.

HOW DOES IT WORK?
Freezing halts, or at least dramatically slows down, the action of enzymes (which break down vitamins for example) occurring from the moment food is harvested. The cold also stops micro-organisms, such as bacteria and yeasts, from growing, spreading and spoiling the food.

Many fruit and vegetables can be stored in a deep-freezer for up to twelve months – giving you year-round access to home-grown goodness. You should never need to keep anything longer than a year. So if frozen produce gets this old, discard it and replace it with smaller quantities of freshly harvested crops.

If you’re serious about storage you will soon find you need a chest freezer (or two)! For the average home the ideal combination would be to have an upright fridge-freezer in the kitchen, where you can store small amounts for quick access, and then a chest (or upright) freezer in a garage, utility room, etc., for the bulk of your frozen produce.

GENERAL GUIDELINES

*          Freeze food as quickly as possible after harvesting: some produce, like peas and sweetcorn for example, will start to lose their sweetness within minutes of being picked.

*          Freeze produce when it’s at its best. If you don’t like tough, stringy beans you won’t like them after they’ve been frozen either.

*          Pack food in appropriate plastic bags or containers. This is partly to exclude as much air as possible, since air dries out the food and slows freezing. Save old ice cream containers, margarine tubs and yoghurt pots for use in the freezer.

*          Label your packages – write on the bag or container with a waterproof pen – mentioning what it is and, importantly, the date of freezing.

*          When food is frozen after blanching (or cooking), make sure it is completely cool before putting it in the freezer.

*          If you are freezing liquids such as fruit juices, remember they will expand as they freeze. So freeze in plastic bags inside old drinks cartons – once frozen, the blocks can be stacked with no wastage of space. Or freeze in empty (and well-cleaned) plastic milk containers – but leave a space at the top for expansion.

*          Cook, or eat, food as soon as possible after it comes out of the freezer – as the spoiling enzymes will start working again straightaway (as well as any bacteria or fungi that may have contaminated the food).

*          Vegetables are generally best cooked from frozen, while fruits are better left to thaw slowly in the fridge.

open freezing raspberries copy

OPEN-FREEZING

Some fruit and vegetables (e.g. broccoli) stick together in a lump when frozen, making it difficult to remove small portions later without smashing the lump to green shrapnel.

The solution is ‘open-freezing’: simply lay the food out on a baking sheet so that the individual pieces are not touching, and place this in the freezer. When frozen, the food can be placed in a bag or container to exclude as much air as possible. Now when you come to use the frozen food it should be suitably loose. Some freezers have a pull-out tray in the top specifically for this purpose.

cabbage

TO BLANCH OR NOT TO BLANCH?

Blanching is the immersing of the fresh produce in boiling water for a minute or two immediately before freezing – it is recommended for nearly all vegetables. This action slows down the enzymes that cause the food to deteriorate – even while frozen. This improves the colour, flavour and nutritional value of the food.
As a rule of thumb, blanch small pieces of vegetable (e.g. peas, beans) for one minute, and larger pieces (e.g. cauliflower, parsnips) for two minutes. A few exceptions to this are noted in the specific suggestions below.

COOKED PRODUCE

Some fruit and vegetables can be frozen after they have been cooked, for example new potatoes, tomato purée, stewed apples or plums, and of course many cooked dishes such as soups and stews freeze well.

SPECIFIC SUGGESTIONS

*          GLOBE ARTICHOKES

Remove the outer leaves and stalks of small heads and blanch for 6 minutes before freezing in plastic bags.

*          JERUSALEM ARTICHOKES

These can be cooked and mashed to a purée before freezing in plastic boxes or bags. This purée can be used later in soups.

*          AUBERGINES

Peel and cut them into thick slices or chunks and then blanch for 4 minutes. Open-freeze them before packing into containers.

*          BEETROOTS (SMALL)

They should first be washed and boiled whole for 1 or 2 hours in salted water. Then the skins can be rubbed off (if desired) before slicing and packing in containers for the freezer.

*          BERRIES

Many berries and currants can be frozen fresh straight after picking. Remove the stalks, open-freeze, then bag-up. They can also be frozen as a purée after stewing and sieving.

*          CAULIFLOWERS

Cut them into florets and blanch for 2 minutes before freezing. Adding a little lemon juice to the blanching water will help the cauliflower keep its white colour.

*          CELERIAC

Wash, peel and cut the root into chunks and blanch for 4 minutes before open-freezing. These chunks are a great addition to soups and stews. They can also be frozen as a purée.

*          HERBS

Freezing is an excellent way of keeping the flavour of herbs. The most useful method is to chop the herbs and freeze small amounts in ice cube trays in water or vegetable cooking oil. In each cube, put about as much as you like to use in your favourite recipes. Either freeze each herb separately or make up your own mixtures. Once frozen, the cubes can be tipped into plastic bags and placed back in the freezer so you don’t run out of cube trays. Label carefully, as ice cubes containing green bits look remarkably similar. When needed, simply add a herby ice cube or two to your cooking. If frying, make it a herby oil cube!

*          LEEKS

Top and tail and wash them carefully to make sure there is no soil left between the layers of skin. Slice thickly and blanch for 3 minutes before bagging-up and freezing.

*          PEAS

Pick peas while tender, and shell and blanch them for 1 minute before bagging-up and freezing. Varieties where you eat the pod too – such as mangetout and sugar snap – can be frozen whole or sliced after blanching for 2 minutes.

*          PEPPERS

Both capsicums and chilli peppers can be frozen for later use in casseroles, curries, etc. First, remove the stalks, then cut them in half and scrape out the seeds and white pith. Blanch capsicums for 3 minutes, and smaller chillies for 1 minute – bag-up when cool, and then freeze.

*          POTATOES

Smaller new potatoes can be frozen after blanching for 3 minutes. Or peel and slice them into chips, then blanch in oil, drain, and freeze in bags. Thaw chips before deep-frying. Potatoes can also be frozen after cooking – roasted or mashed.

*          ROOT VEGETABLES

Many roots, such as parsnips, carrots, swedes and turnips, will freeze well. Trim, peel, and cut them into chunks before blanching for 3 minutes. Place in plastic bags in the freezer. To cook from frozen, boil for about 10 minutes or add frozen chunks direct to soups or stews. Many roots can also be boiled, mashed and frozen in the cooked state. Try mixing roots in mashes – carrot and parsnip together for example.

*          SPINACH

Wash the leaves well then blanch them for 2 minutes. Cool and squeeze out the excess water before freezing in plastic bags. It will freeze as a solid lump, so fill each bag with only as much spinach as you will need for one meal.

*          SWEETCORN

Pull off the outer leaves and silks, trim the stalk, and blanch for 5 minutes. After cooling, wrap each cob in foil or cling film before placing in the freezer. Alternatively, strip the corn kernels from the cob using a knife and then blanch them for 1 minute before bagging-up and freezing.

*          TOMATOES

The easiest way is to just put them whole into the freezer. They can easily be skinned after freezing by immersing the frozen tomatoes in hot water for 1 or 2 minutes, after which time the skins will slide off when the fruit is squeezed – these can be added to stews etc. They can also be frozen after stewing to a purée – for use as a base for pasta sauces etc. Simmer for 5 minutes, then sieve before freezing in a plastic container.

See also How to Pickle Food, How to Dry Food

Piers Warren is the author of How to Store Your Garden Produce: The key to self-sufficiency, published by Green Books and sold in The Home Farmer Store

 

About the Author:

Ruth Tott is the publisher of Home Farmer Magazine, and together with her husband, Paul Melnyczuk, Editor,is founder of the company. But her background is far removed having specialised in Costume History with a Post-Grad diploma in Museum Studies to boot. A far cry from looking after chickens, growing veg and making bread!

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