8
Microwave energy has been used in this country to cook and reheat food
since early experiments with RADAR in World War II. Microwaves are
present in the atmosphere all the time, both naturally and from manmade
sources.
Manmade sources include radar, radio, television, telecommunication links
and car phones.
Microwaving Principles
The microwaves cause the water molecules to vibrate which causes
FRICTION, i.e. HEAT. This heat then cooks the food. Microwaves are
also attracted to fat and sugar particles, and foods high in these will cook
more quickly. Microwaves can only penetrate to a depth of 1
1
⁄
2
-2 inches
(4-5 cm) and as heat spreads through the food by conduction, just as in
a traditional oven, the food cooks from the outside inwards.
In a microwave oven, electricity is converted
into microwaves by the MAGNETRON.
REFLECTION
The microwaves bounce off the metal walls
and the metal door screen.
TRANSMISSION
Then they pass through the cooking
containers to be absorbed by the water
molecules in the food, all foods contain
water to a more or lesser extent.
IMPORTANT NOTES
HOW MICROWAVES COOK FOOD
The dish used to cook or reheat the
food will get warm during cooking, as
the heat conducts from the food. Even
in microwaving, oven gloves are
required!
MICROWAVES CANNOT PASS
THROUGH METAL AND THEREFORE
METAL COOKING UTENSILS CAN
NEVER BE USED IN A MICROWAVE,
FOR COOKING ON MICROWAVE
ONLY
Foods Not Suitable for Cooking
by Microwave Only
Yorkshire Puddings, Souffles, Double
Crust Pastry Pies.
Because these foods rely on dry
external heat to cook correctly, do not
attempt to cook by microwave.
Foods that require deep fat frying
cannot be cooked either.
STANDING TIME
When a microwave oven is switched off,
the food will continue to cook by
conduction – NOT BY MICROWAVE
ENERGY. Hence STANDING TIME is
very important in microwaving,
particularly for dense foods i.e. meat,
cakes and reheated meals (Refer to
page 9).
Boiled Eggs
Do not boil eggs in your microwave.
Raw eggs boiled in their shells can
explode and cause serious injury
13 Amp fused socket
Microwave Water Molecule Absorption Vibration
