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, 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 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 10).
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
IMPORTANT NOTES