Microwaving Principles - John Lewis JLFSMW001 Instruction Manual

Microwaving principles

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.
Man made sources include radar, radio,
television, telecommunication links and car
phones.
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.
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 / -2 inches (4-5 cm) and as heat
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spreads through the food by conduction,
just as in a traditional oven, the food cooks
from the outside inwards.
Important notes
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
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 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 8.)
Boiled eggs
Do not boil eggs in your microwave. Raw
eggs boiled in their shells can explode and
cause serious injury
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