PRESERVING AND PROCESSING FOOD
Preserves include pickles, bottled vegetables, chutneys and sauces. Preserves will normally keep for a minimum of 12 months at room temperature in a pantry. Containers must be sterilised before use to prevent contamination by bacteria and other microorganisms.
How to sterilise jars or bottles:
1. Wash thoroughly in hot water, invert and drain.
2. Just before filling, place in a 40 degrees C oven to warm up.
3. Remove and immediately fill with the preserve (while the jar is still hot).
You should not put a hot preserve in a cold jar or a cold preserve in a hot jar.
Pickles are vegetables preserved in salt and vinegar.
Sugar or honey is sometimes added to produce a more subdued flavour in a pickle. Herbs or spices are sometimes also added to the solution as a flavouring.
1. Vegetables are cleaned and washed (sometimes blanched).
2. Jars are sterilised in boiling water.
3. Vegetables are packed into jars either whole or sliced.
4. A solution of salt in vinegar (with any appropriate additives) is boiled, then poured into
5. The lids are put on while still hot.
NOTE: Heat‑resistant jars must be used.
Pickles must be left at least 2 to 4 weeks to mature before eating.
Vacuum‑seal jars are the best containers to use.
Tomatoes are best bottled with their skins removed.
1. Fill the jar with whole tomatoes (large fruits can be cut in quarters).
2. Weigh, and add 1 teaspoon sugar for every 250 g of fruit to the jars.
3. Make up a solution of salt water (1 tablespoon of salt to 5 cups of water) and boil.
4. Preheat the oven to 150 degrees C.
5. Warm jars by standing in a sink full of hot water.
6. Pour boiling solution over the fruit to fill the jars.
7. Put lids on jars, but loosely, do not seal ‑ air must be able to escape.
8. Place on a baking tray on top of 4 sheets of paper and put into the oven.
9. After 70 to 80 minutes remove from the oven if the lids have remained firmly in place, a vacuum has been effected. The lid tops can be clipped down. If the seal is broken, use immediately or reprocess.
Chutneys are vegetables cooked in salt, vinegar, sugar and herbs until they become soft and smooth in texture. They are best cooked slowly for a long time, then put into sterilised jars or bottles and immediately sealed. Do not use metal saucepans as contact with metal can reduce the keeping quality; use Pyrex or enamel saucepans instead.
Sauces are prepared in much the same way as chutneys. They may be passed through a nylon sieve or plastic strainer after cooking to remove any coarse material. Again, do not use metal sieves, as contact with metal can reduce the keeping quality.
Fruit or vegetables should be frozen on the day they are picked to ensure the least loss of flavour and colour. Most frozen fruit or vegetables will retain their nutrients and flavour, but some will lose their consistency when thawed out. Tomatoes, for example, become mushy, but they can still be used in cooking. Once thawed out, vegetables should not be refrozen.
Vegetables particularly suited to freezing include peas, beans, soybeans, corn and asparagus.
1. Pack food in airtight containers such as plastic freezer bags or plastic sealable containers.
2. Before sealing the container, remove as much air as possible.
3. Write the date of processing on the container. Most frozen vegetables can be kept up to 8 months in a standard home freezer.
4. When you put the container into the refrigerator, place it as close as possible to where the refrigerant circulates. This is the coldest part and is where freezing will be fastest.
Leave a small air gap between containers when first freezing. This increases the rate of freezing. You might turn the freezer up to high when first freezing then turn it back later.
Avoid too frequent opening of freezer door when a new batch of vegetables is being stored.
Some books (particularly older ones) will suggest that vegetables should be blanched before freezing. Blanching is a process of cooking or part cooking. Some people believe it reduces the pungency of certain strong flavoured vegetables (e.g. cabbage or onions) while others believe it is necessary for the freezing process (although others will argue that it most cases it is unnecessary).
How to blanch:
Put prepared vegetable into 1 to 2 litres of boiling water or steam it for several minutes.
Plunge the vegetable into iced water to rapidly cool. These extremes of temperature are said to kill harmful bacteria and keep the vegetable fresh.
Allow to dry thoroughly before placing in freezer bags.
MANAGING THE FREEZER
You should plan what you freeze. Keep a written record of what you freeze and when you freeze it, so you can see which is the oldest food, which should be used first. When you remove something from the freezer, mark it off on your record. Plan how much of each crop you put into the freezer, so you don't end up with too much of one thing and too little of another.
The size of your freezer.
How much food your family needs.
The best times to grow particular crops. What time of year will the produce be ready? What time of year will there be room in the freezer?.
The time needed to prepare and pack food for freezing.
Want to Learn More?
Check out agricultural publications in the ACS Bookshop: http://www.acsbookshop.com/books_productcategory.aspx?id=5
For more information on Food and Hospitality Courses http://www.acsedu.com/courses/product_listings.aspx?catid=Hospitality