9
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, ie. 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.
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 micro waving, oven gloves
are required!
MICROWAVES CANNOT
PASS THROUGH METAL
AND THERE FORE METAL
COOKING UTEN SILS 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.
This is because these foods
rely on dry external heat to
cook correctly, do not attempt
to cook by micro wave.
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 11).
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
Important Notes
Magnetron
Wave Guide
Turntable
Oven cavity