|
by Bob Devine
Saccharomyces cerevisiae translates to sugar
eating beer fungus....
SIMPLE AND REFINED SUGARS
glucose / dextrose / corn sugar :
Glucose is a monosaccharide. This simple sugar is
derivable from converted starches such as what happens
when mashing malted grain. Sugar processors can
make this sugar from a variety of sources - corn
(maize), wheat, rice, potatoes, in short, anything
with cheap starch can be a input into the process.
However if not completely refined down to simple
sugars, some of the origin can be discerned.
The right handed variation of glucose is called
dextrose.
maltose :
A dissacharide made up of two glucose molecules.
Completely fermentable. Contributes ~45 points per
pound.
fructose / "fruit sugar":
Another monosaccharide. In all-malt beers, this
normally appears as only few percent of the wort.
Yeasts will rapidly ferment this but there might
be some problems (I can't recall but I seem to remember
that Dave Miller's book describes the problem as
a "spill over effect" that causes some off-flavors
due to the production of different fermentation
products.)
Fructose tastes much sweeter than glucose or even
the combination of fructose + glucose (= sucrose).
That's why big food processing companies use "high
fuctose" sugars because they get more bang for the
buck by using less of a sweeter tasting sugar. On
the other hand, to continue the digression, lots
of hard-core CocaCola drinkers like the less sweet
sugars since it requires more which makes a thicker,
more viscous soft drink.
See the entry for "sucrose" for a description of
how the "high fructose" syrup is made.
Fructose is also called levulose because that form
rotates light in a left handed direction.
sucrose / table sugar / cane sugar :
Sucrose is a disaccharide composed of one molecule
of glucose and one of fructose. More precisely,
it is dextrose plus dextrorotary fructose. It must
be broken apart before the yeasts can use it. When
heated in an acidic solution (such as wort) the
sugar is inverted to make D-(+)-glucose and D-(-)-fructose.
Yeasts will invert the sucrose if it is not already
in that form before using by using invertase. It
is derived from sugar beets or sugar cane that are
crushed and dissolved in water. The raw syrup is
boiled down to concentrate it to a point where some
fraction crystallizes. The remaining heavy syrup
(see "molasses") is separated from the 95+% pure
sugar. The crystals are further processed several
times to increase its purity yielding, eventually,
the pure white crystals we commonly use. Some other
commonly used sugars are also produced during the
processing.
A complaint in the early days of modern homebrewing
was that using table sugar in beer-making resulted
in a "cidery" beer. The symptoms were that a beer
made with table sugar that was added to the boil
produced a cidery flavor that faded after several
weeks in the bottle. Therefore the rule of thumb
became 'avoid all table sugar'. While this is still
a good idea when using malt extract, this old-(ale)wives
tale is misleading. That defect most likely came
from poor yeast due to a too low pitch, insufficient
free-available-nitrogen, or a lack of other necessary
yeast building materials in the wort. Table sugar
can be used in small amounts with no harm and it
is certainly cheaper to use for priming.
This simple colorless sugar will lighten the body
of a beer since it can be completely fermented.
It also lightens the beer color.
SYRUPS, PROCESSED SUGARS
Invert sugar :
This is simply sucrose (aka, table sugar) that has
been subjected to "hydrolysis" which breaks the
disaccharide sucrose into its constituent sugars.
The fructose is inverted (made into its optical
isomer). The inversion process involves adding acid
and is usually done at high temperatures to speed
up the process. Alternately, the invertase enzyme
can be used.
raw sugar :
The only unrefined sugar available to the average
consumer seems to be Sucanat, an evaporated sugar
cane syrup. Raw beet sugar is reputed to be unsavory.
It may be possible in some markets to get other
raw sugars (e.g., in Hawaii, pineapple sugar may
be sometimes found).
Demerara / turbinado :
This is crystalizable sugar from the first step
of refinement. It has a tan to brown color from
the residual impurities. Some food faddists attribute
beneficial results from using this but unless a
lot is consumed, the potential benefits are very
low. Demerara is the UK term; turbinado the US (and
Spanish language?) term. Demerara is usually a dark
brown shade while turbinado is lighter, more of
a tan or taupe color. It is 98% sugar with some
residual proteins and unfermentable carbohydrates
present.
molasses / treacle :
This is the residue of the sugar after the crystalized
portion has been removed. The choice of names for
this sugar syrup seem to reflect regional language
preferences rather than any major differences. In
the US, "molasses" is the preferred term while in
the UK and ex-colonies, "treacle" is used. Regular
treacle is an inverted sugar produced from the residue
of refinement. The acid treatment darkens it. Molasses
is filtered and may have a sulfur compound added
to sterilize and stabilize it.
"Black treacle" is roughly the same flavor as "blackstrap
molasses" however treacle may be produced differently.
While there are differences between the differently
named syrups, there is also a wide variability within
syrups of the same name! Find one company's product
you like since that may be the only level of consistency
obtainable.
Light molasses is roughly 90% sugar. Blackstrap
is about 50% sugar and has a wide variety of crud
remaining.
golden syrup :
Like molasses, this is a syrup that remains after
the crystallizable sugars have been removed. However,
since the syrup is removed later in the refinement
process, it does not have as heavy a taste or color
as molasses. Lyle & Tate's product is derived from
cane sugar. The syrup has been inverted using a
strong acid (hydrochloric acid, I think) and then
counter-acted by the addition of base (NaOH) after
a short time. Some of the golden color is from the
acid treatment. A salty taste comes from the acid
+ base combining to form NaCl.
brown sugar :
In the US, this is just refined sugar with some
molasses added back in. The US food law says that
only refined sugar (no raw components) can be sold
with this name. This law may actually have more
to do with enforcing a similar taste for both sugar
beets and sugar cane since the beets, when un-refined,
have a poorer taste than cane. [ Sidenote: with
the possible elimination of sugar support prices
in the US, this category may change...] Compare
this to Piloncillo (Mexican brown sugar) which is
a semi-refined granulated sugar.
candy sugar / Belgium candy sugar / sucre candi
/ candij sugar :
This sugar is commonly used in Belgium beers. It
comes in several colors - light to dark. When added
to beer, it thins out the high gravity beers and
contributes color and, for the dark version, some
residual caramel flavors. Candy sugar is sucrose.
Its production is the same as for rock candy (i.e.,
slow crystallization of a concentrated sugar solution)
made from straight sucrose so a brewer should be
able to substitute regular sugar for it. Dark candy
sugar has been carmelized before it is crystalized.
corn syrup :
Basically glucose with water. May have maltose.
Beware about buying the typical grocery store version
because it _might_ have some vanillin/vanilla as
a flavoring. Additionally, some brands have a preservative
that could affect fermentation. Dark corn syrup
is just the regular syrup with some coloring. Use
wherever you would use straight glucose/dextrose
such as priming.
Honey :
Honey is a complex mix of sugars but it is mainly
glucose (roughly 30%, by weight) and fructose (40%)
in invert form; the bees supply the invertase, which
is the enzyme that inverts the fructose. Honey's
make-up is not consistent - it varies by source,
season, region, and producer. It is about 75% fermentable
sugar; the remainder is water, proteins, some minerals,
etc.
jaggery :
Un- or semi-refined date sugar.
lactose / milk sugar :
An unfermentable sugar (at least by ordinary beer
yeasts) often used to boost the residual sweetness
as in "milk stouts".
maltose syrup :
Some UK recipes call for this. To make it, you mix
glucose and a dextrin powder in a 4:1 ratio. The
20% dextrin will remain unfermented and therefore
lends body and mouthfeel that a pure sugar syrup
would not.
|
