A sauce is a liquid that has been thickened by either:
A. beurre manié
B. egg yolks
C. roux
D. cornflour, arrowroot or starch
E. cream and/or butter added to reduced stock
F. rice in the case of some shellfish bisques)
G. reducing cooking liquor or stock.

We will take a closer look at some of these beiow.

All sauces should be smooth, glossy in appearance, definite in taste and light in texture; the thickening
medium should be used in moderation.

Beurre manié
Beurre manié is a paste made from equal quantities
of soft butter and flour, which is then added to a
simmering liquid while whisking continuously to
prevent lumps torming.

Egg yolks
Egg yolkS are used as a basis for a liaison, which is
traditionally used to thicken a classic velouté (see
recipes 24 and 25). Both egg yolks and cream are
mixed together and added to the sauce/velouté off
the boil; this mixture is intended to thicken, however it
is essential to keep stirring it, otherwise the eggs wil
curdle. Once thickening is achieved the sauce/veloute
must be removed and served immediately. The liquid
must not be allowed to boil or simmer.
Egg yolks are used in mayonnaise (page 97),
hollandaise sauce (recipe 47) and custard sauces
(page 486). Refer to the appropriate recipe, though,
as the yolks are used in a different manner for each
sauce. When making mayonnaise (where the yolks
are not cooked) or hollandaise (where temperatures
remain low), it is advisable to use pasteurised eggs tor
food safety reasons.

Sabayon
A sabayon is a mixture of egg yolks and a little water
whisked to the ribbon stage overa gentle heat. The
mixture should be the consistency of thick cream. It iss
added to sauces to assist their glazing.

Cornflour, arrowroot or starch
Cornflour arrowroot or starch (such as potato starch)
is used for thickening gravy and sauces. These are
diluted with water, stock or milk, then stirred into the
boiling liquid, allowed to reboil for a few minutes and
then strained.

Roux
A roux is a combination of fat and flour, which are
cooked together. There are three degrees to which
a roux may be cooked (white, blond and brown) and
one approach known as ‘continental” roux style (see
below)
A boiling liquid should never be added to a hot roux
the result may be lumpy and the person making
the sauce may be scalded by the steam produced. If
allowed to stand for a time over a moderate heat, a
sauce made with a roux may become thin due to a
chemical change (dextrinisation) in the flour.

White roux
This is used for white (béchamel) sauce and soups.
Equal quantities of butter and flour are cooked
together without colouring for a few minutes, to a
sandy texture. Alternatively, use polyunsaturated
vegetable margarine or make a roux with vegetable
oil, using equal quantities of oil to tlour. This does give
a slack roux but enables the liquid to be incorporated
easily.

Blond roux
This is used for veloutés, tomato
sauce and soups. Equal quantities of
butter or vegetable oil and flour are
cooked for a little longer than a white
roux, but without colouring, to a sandy texture.

Brown roux
This was traditionally used for brown
(espagnole) sauce and soups and is slightly browned
at the roux-making stage.

Continental roux
This is a very easy and straightforward thickening
agent that can be frozen and used as a quick
thickener during service or à la minute.
Mix equal quantities of flour and vegetable oil
together to a paste and place in the oven at 140°C.
Cook the mixture, mixing it in on itself periodically
until a sandy texture is achievéd. Remove and allow
to cool to room temperature. When it is cool enough
to handle, form into a sausage shape using a double
layer of cling film. Chill, then freeze.
To use, remove from the freezer and shave a little
off the end of the log. Whisk it into the boiling sauce
(as the flour is already cooked it is not necessary to
add it slowly to prevent lumping as this will not occur).
Once the desired thickness has been achieved, pass
and serve.

Thickening sauces with sauce flour Sauces may be thickened using this flour, which is a
specially milled flour that does not require any addition of fat to prevent it from going lumpy. It is useful when
making sauces for those on a low-fat diet.

Other sauces
Vegetable or fruit purées are known as a coulis. No
other thickening agent is used.
Blood was traditionally used in recipes such as
jugged hare, but is used rarely today.
Cooking liquor from certain dishes and/or stock
can be reduced to give a light sauce.

Espagnole
This is a traditional brown sauce made from brown
roux and brown stock, simmered for several hours
and skimmed frequently to produce a refined sauce.
Because of the lengthy, time-consuming process and
a move away from heavy flour-based sauces, in many
kitchens a reduced veal stock (see recipe 30) is used
as a base for most brown sauces.

Demi-glace
Demi-glace is used as the base for a number of
derivative sauces. Current practice in most kitchens
is to use either stock-reduced sauce, jus-lié or a
commercially produced powder or granule-based
product.

Salsa
Salsa is the Spanish word for a sauce. A wide variety
of ingredients can be used and chunky mixtures made
to serve with grilled or fried fish, meat and poultry dishes.

Butter as a sauce
Clarified butter
Clarified butter is butter that has been melted and
skimmed. After that, the fat element of the butter
is carefully poured off, leaving the milky residue
behind. This gives a clear fat that can reach higher
temperatures than normal butter without burning, but
that can also be used to nap over steamed vegetables,
or poached or grilled fish.

Beurre noisette
Beurre noisette basically translates to ‘nut butter, and
its flavour comes from the caramelisation of the milk
element in the butter solids. It is achieved by placing
diced hard butter intoa moderately hot pan and
bringing to a foam (a good indication that it is ready).
Like clarified butter, this can be served with poached
or steamed vegetables and fish, but the classic use
is with shallow-fried fish. If you take the buttera little
further, however, and almost burn the sediment, then
add a little vinegar, this is called black butter (beurre
noir) and is traditionally served with skate.

Beurre fondu/emulsion
This is basically an emulsion between fat and liquid-
for example, melted butter emulsified with any nage
described above will give you a slightly thicker sauce
that can be used to coat vegetables or fish. However,
to intensify the flavour, if you were to add a beurre
noisette to the pan, or your cooking medium was
clarified butter, you could start cooking the product in
the pan with the fat. Once it is half cooked, stop the
cooking by adding a nage and then bring quickly to the
boil. Through this boiling process the fat and the stock
will become emulsified, which gives an emulsified
sauce made in the pan, but with the cooking juices
also added.

Compound butter sauces
Compound butters are made by mixing the flavouring
ingredients (e.g. herbs) into softened butter, which can
then be shaped into a roll 2 cm in diameter, placed in
wet greaseproof paper, foil or clingfilm, hardened in a
refrigerator and cut into 0.5 cm slices when required.
Parsley butter: chopped parsley and lemon juice.
Herb butter: mixed herbs (chives, tarragon, fennel,
dill) and lemon juice.
Garlic butter: mashed to a paste.
Compound butters are served with grilled and some
fried fish, and with grilled meats.

Flavoured oils
Flavoured oils are used to enhance certain types of
tood and dishes, especially pasta, fish and salads.