Thickening Agents - Roux
Roux has been used in the Culinary
industry for a long period of time up to date. Not only it's
practical to its usage, roux is also very useful in terms adding
flavor to soups or sauces. There are many stipulations to Roux
as there is with politics today, as this long-time French thing
is found so useful that many practice this product, use it
differently and sometimes, perceive it differently.
What roux can bring to you
today is its basic understanding and use. Nothing could be
further from roux-truth than to practice this concept of using
roux:
Warm Liquid --> Hot Roux
Warm Roux --> Hot Liquid
Typically, what Chefs need to
understand in the kitchen is that, Roux isn't just one type of
thickening agent or emulsifier, if you want to put it that way.
There are many other alternatives to roux also, such as potato
starch, tapioca starch, corn flour, etc. These starches have
their own strengths and weaknesses, therefore increasing the
likelihood of a particular menu to 'vary' of a thickening agent
or an emulsifier's usage.
Other thickening agents such as
corn, potato, arrowroot, tapioca, and wheat are particularly
special themselves, and the below explains their properties.
Thickening Agents' Properties
There are many sorts of
thickening agents out there in the market - Food Central uses
only a few by far, due to costing and practicality factors. For
certain kitchens, it's advisable to use certain things, and
also, depending on its properties, thickening agents can work
well under certain conditions and vice versa.
- Stability
How stable is that particular
thickening agent when it's mixed into the liquid - Whether
the liquid will be thick when it's hot, or will be thin when
it's cold, or vice versa. Temperature is the core of your
thickening agent's stability. Also, it also covers thick,
long cooking process. Will long cooking thin out (separation
of molecules) your thick liquid?
- Consistency
Consistency as in when starch
is incorporated into the liquid, what would probably be the
texture of the soup? Use a spoon, scoop up some liquid and
pour it back in - Does it have a smooth flow, or does it
come close to a stringy-like texture or is it forming
lump-like texture of sorts?
- Flour-flavor
Will the thickening agent I
use contaminate the soup or sauce that I'm using with its
uncooked flour smell, or will my strong flavored soup cover
the uncooked flour-smell? Take into consideration volume and
thickening agent strength when you're deciding which
thickening agent to use.
- Holding Strength
How much of the mixture of
flour and water do I need to incorporate into my liquid
before it thickens out to the consistency that I'm looking
for? Do I need two tablespoons of corn starch for this
amount of liquid to get there or two tablespoons of potato
starch?
- Transparency, Opacity and
Color
After the
thickening has been mixed into a liquid, will it be
transparent or will it yield a little sight of cloudy,
opaque-like color over the liquid?
Roux
Roux is the one best thing to add when you're cooking it for
small dishes or soup. They come in powdered formats now, and you
can get them if they are available in your local store.
- Medium-weak holding power.
Cooking the roux too long will weaken its holding power.
- Stability - The good part
about roux is that it holds (after being incorporated well)
the sauce at its thickening point even after the liquid is
cooled off. Certain starches like tapioca and corn does not
hold very well when it's cooled down.
- Robust flavor - Roux has a
very complex flavor of its own, especially when it comes to
the kind of 'fats' you want to add in. Choose 'fats' that
have higher heating point. E.g. Sunflower Seed oil or
Peanut. Butter is commonly used, but animal fats are also
fine, if you want a more robust flavor.
- Color - Varies. If you're
looking for the traditional dark roux, cook the flour a
little longer before incorporating your fats. If you're
looking for a white roux which needs little color influence,
don't burn your flour.
- Consistency - Like the
potato starch, it should be running in a very streamlined
position and springing back up a little.
Potato Starch
Potato starch is known to be one of the most expensive
among other flours here in Malaysia. It has:
- Great strength and holding
power - Use only a bit to yield a thick sauce.
- Stability: Quite weak.
When you're heating up a sauce that requires thickening,
consider bringing it to a close boil, add this and turn off
the fire as soon as possible. Overheating will cause the
molecules in potato starch to break and this will result in
a thin liquid.
- Semi-light flavor - Not
very powering to the tongue when you thicken your liquid.
Since its strength is good, you do not need to add too much,
this will leave the liquid clear of its flour-like favor.
- Potato starch has no color
influence when it's added to your liquid. Don't ask for
trouble by cross-contaminating it.
- Consistency - Silky and
stringy. When you scoop some up and pour it back down, it
should be in a very steady stream, with little silky strings
dropping off like a calm waterfall, then when it goes back
up, the stream will slightly bounce back up to the spoon.
Potato starches are great for
quick thin sauces that requires only a small amount of cooking
time or remaking of it. Keep in mind that in order to get a
consistent thickening agent, ensure that your ratio of flour to
water is at least 1:5. Mix them well - Because after leaving it
for long, the starch will fall off and you'll see water on top
of the flour.
Corn Starch
Corn flour is known to be one of the most important
flours to have in a kitchen other than just the regular cake and
bread flour, or superfine and Rex Milano (flour mixed with
seasoning and herbs, used for Pizza dough). Not only used as
coating or flour mixture in the hot kitchen, it also has its
uses in the Pastry kitchen, for example; Pavlova.
- Medium strength - Corn
starch is not very strong compared to Tapioca or Potato
starch. Due to its natural properties, corn flour is used
more for stabalizing rather than thickening. (Although we
don't deny that there are a lot of us who use corn flour as
a thickening agent)
- Medium-weak stability -
Corn starch also has the potential to break down if you cook
it too long, or when your temperature is not high enough
(medium-high simmer). Always bring your liquid to a close
boil before attempting to add corn starch into it.
- Very strong flavor -
Apprentices usually make a mistake here: They replace roux
with cornstarch which is totally acceptable, but only at a
certain degree/extent and depending on what we're
thickening. Be sure that for a 1 quart pot of water, you
have no more than 4 tbsps of this.
- Color - Cloudy, medium
high in opacity.
- Consistency - Smooth. Your
liquid should be streaming in a very straight line, thick
but not lumpy. It should not bounce back up to the spoon.
Too much will result in lumps.
Tapioca Starch
Tapioca starch holds stronger than corn starch, and is
particularly used as an alternative choice in the kitchen or to
bake breads and pastries. Also, tapioca starch smoothens clothes
(used by old-timers) during washing by soaking clothes into the
tapioca starch solution first before hand-washing them.
- Medium-strong thickening
agent - In cooking when there are small amount of sauces (in
a dish), tapioca flour is used to thicken its 'juices',
mainly for the purpose of creating a thicker sauce rather
than a thin one.
- Weak stability - The bad
thing about tapioca starch is that it breaks down a little
quicker than corn starch. Especially when you're on a very
high temperature, they have the tendency to 'thin-out'
faster than potato or corn starch.
- No flavor - That's the
best part of tapioca starch.
- Clear, low opacity and
almost transparent in color.
- Stringy consistency - You
should see a smooth flow when you scoop it up and pour it
back to the soup, while it slightly springs back up when it
finishes.
Although it has no odour, care
must be taken as too much of it will result in a jelly-like lump
- Avoid that at all costs.
Always keep in mind that
thickening agents are useful tools to help you thicken your
sauce. However, it's always advisable to bring your liquid to a
near boil to achieve any thickening at all. Simply adding it in
the sauce when it's warm or cold will not yield results - But
they will when it's hot. And that's when everything will spoil.
