EVERYTHING
YOU NEED TO KNOW ABOUT SULFITES
| Preservatives
are an important part of wine making. Don't worry that adding them to your
home-made wine. Not only do they keep wine from developing infections,
they also keep the wine from oxidizing. If you are concerned about the
use of sulfites in wine read on! |
| Preservatives are an important
part of wine making. Don't worry that adding 'preservatives' to your home-made
wine. The thing we most often recommend is sulfite, and it occurs naturally
in small amounts during fermentation. Sulfites
are your friend. Not only do they keep wine from developing infections
like film yeast, mould, and acetobacter (vinegar
bacteria), they also keep the wine from oxidizing. Without the use
of sulfites you have to be terrifically careful to keep all of your equipment
very sanitary and you still have to drink your wine up as quickly as possible
before it spoils. |
| Many people worry that they
may be allergic to sulfites. True sulfite allergies are very rare. It's
more likely that they have been exposed to a high level of sulfites in
the past. In the 1970's restaurants would douse their salad bars with 2000
PPM (part per million) sulfite solutions in order to keep the produce fresh.
Mixing this with acidic foods, such as salad dressings or vinegar, would
cause the salad to release clouds of sulfite gas, provoking unpleasant
reactions. |
| What most people describe
as a sulfite headache is a reaction to bio-amines. These are compounds
formed in wines for various reasons, one of the commonest being malolactic
fermentation in the presence of sugar. Some commercial wineries start malolactic
inoculation before the end of alcohol fermentation, guaranteeing the formation
of bio- amines. Since wine kits don't go through malolactic they do not
form bio-amines, and consequently don't provoke allergic reactions. |
| People familiar with bread
making, or who have knowledge of beer making
will want to re-hydrate the yeast prior to pitching it. This contradicts
our instructions, which direct you to sprinkle the yeast directly on top
of the juice. Who are you going to believe? You can re-hydrate the yeast
if you wish, but be aware that anything less than utterly strict adherence
to proper re-hydration procedures will kill your yeast instead of helping
it. There's a long scientific explanation for this, but it boils down to
viability. Simply sprinkling the yeast on top of the must will give you
a higher live cell count than re-hydrating in most cases, and will be far
less trouble. |
| Potassium
Metabisulphite is a stable source of sulfite in winemaking. The use
of sulfur compounds is not a recent innovation. The Dutch shipping companies
popularized the use of sulfur in the 16th century by refusing to ship any
wines not treated. They insisted on the use of sulfites because the treated
wines were the only ones that survived a long sea voyage without spoiling. |
| Sulfites work by releasing
free sulfur dioxide, which inhibits yeast, mould and bacteria. It does
this in two ways: one, it kills some of the organisms outright, and two,
it blocks the surviving organisms ability to reproduce. If your winemaking
equipment is physically clean and you've rinsed it with a sulfite solution,
nothing will grow on it. |
|
|
| Sulfites are also added
directly to wine after fermentation, to help prevent oxidation. Oxidation
in wine follows the same pattern that you see in the cut edge of an apple-the
wine turns brown and takes on a flat 'cardboard' taste. Sulfur binds with
the oxygen in the wine and prevents this damage. |
Some
facts that might clear up any misunderstanding about sulfites:
Sulfites
are a recognized food additive. The federal government controls their use.
.All commercially available wines contain sulfites, even those labeled
'Kosher' or 'Organic'. The legally allowable amount in British Columbia,
where WineXpert kits are made, is 70 PPM.
Nearly
all dried fruits and meats contain sulfites. Raisins, for instance, have
up to 250 PPM. Frozen orange juice, bacon, dried noodles, all contain sulfite.
The amount
of sulfite provided in WineXpert kits will result in a level of between
15 and 30 PPM in a finished wine.
All grape-based
wines produce sulfites naturally during fermentation, up to a level of
about 1O PPM. Even with no addition of sulfites, wines will still contain
them.
This is
not to say that sulfites are totally benign. People with asthma or emphysema
should avoid inhaling sulfite powder or the gas that comes off the prepared
solution. It can act as a bronchial constrictor, aggravating any breathing
problems. Also , adding extra sulfites to wine is of no benefit, as it
can spoil I the flavor, giving it a 'burnt match', smell. It's important
to follow directions for sulfite additions.
The upshot
of sulfite use is this: without sulfites you'd have to be very careful
to keep all of your equipment sanitary and you'd still have to drink your
wine quickly, before it spoiled, probably within one or two months.
A
final, but very important consideration is that if your customer insists
on leaving out the sulfite from their wine kit, they must also leave out
the sorbate. Sulfite suppresses malolactic bacteria, but sorbate does not.
Without any sulfite to prevent malolactic fermentation, the bacteria will
convert the sorbate into hexadienol, producing a stupendously horrible
aroma of composting geraniums and rotting trout. |
|
|
|
copyright
2004 J.R.Leverentz
|
|
|
|
