Troubleshooting Wine Kits and Instructions, Prevention and
If your wine kit suddenly and unexpectedly does something it
never has before, or progresses very differently from the way it
is supposed to, what has happened to it? And what can you do? Do
you have to throw away your entire batch, or is there some way
to fix the problem? When you face something like this, do not
feel bad, and do not discard the wine. Regardless of how
strangely your wine may behave, you are not the first person to
experience the problem.
The good news is that the failure rate of kits is very low. If
you follow the instructions closely and have generally sound
sanitation and storage practices, along with a healthy dose of
patience and the good sense to take and record specific gravity
and temperature readings, the chances are that you will make
good wine 99.9% of the time.
However, failures do occur. That is when it is time for
troubleshooting. We address the major types of problems
(primarily fermentation and visual and odour issues) below, but
your first recourse should always be to carefully re-read your
Winexpert kits sometimes have instructions and procedures that
contradict accepted techniques for fresh grape winemaking. There
are many good reasons for these non-intuitive procedures, but
they all boil down to the same thing: our numerous laboratory
trials have shown that these methods best produce fermentation,
clearing and stabilising. And the number one reason that our
Quality Control laboratory sees for kit failure is departure
from the steps in the instructions.
Logically, it seems that techniques used for grapes would work
best for kits as well, but that turns out not to be the case.
Not only does this apply to the difference between the
instructions for kits and fresh grapes, but it also applies to
instructions between different manufacturers kits. If you are
used to one kind of kit, that does not mean you can apply its
typical instructions to another. The best way to ensure the
greatest incidence of successful kits for the largest number of
users is to follow the instructions that come with a particular
kit, as carefully and accurately as possible.
Keep two important things in mind. First, you will need a good
floating thermometer, a test-jar, and a hydrometer. These are
essential for checking temperatures and specific gravity
readings under normal circumstances, but you will definitely
need them to troubleshoot your wine kit problems.
Secondly, the key to the cure in most cases is prevention. So
even after you have fixed a problem with a current kit, the best
way to improve your winemaking in the future is to keep good,
careful records. Eventually you will be able to diagnose many of
your own problems or repeat your successes, and avoid future
Wine Won't Start Fermenting
When yeast is pitched according to kit instructions, you should
see activity within 48 hours, or at least see a nice, healthy
scum of developing yeast on top of the must. If you do not, the
first step is to take a specific gravity (SG) reading. If it
shows a drop from the original, you are experiencing 'secret'
yeast. For several complex reasons, sometimes yeast like to get
quietly to work without much foaming or fizzing. In this case,
the immediate solution is to wait and take another SG reading a
day later, to confirm the progress of fermentation.
If the gravity has not dropped, double-check that you have
actually added the yeast. On the first day, sometimes the
multiple activities expected of you (adding the right amount of
water at the right temperature, stirring in additives, etc.) can
get confusing. If you find your package of yeast sitting inside
the box, or think you may have discarded it, add yeast
immediately. If you can not find the package that came with the
kit, make sure you add an identical strain to the one originally
in the kit; it is the only way to be sure that your kit turns
out the way it was intended to. Check your gravity for the next
three days to make sure that fermentation is proceeding
If you know you added yeast, and it still is not fermenting,
check the temperature of the must. Kit wines are all designed to
ferment at room temperature, generally in a range of 18 to 23°C
(65 to 75°F). If it is above 40°C (104°F), you may have added
too much hot water to the must, and the yeast is likely dead.
Cool the must by freezing a couple of bottles of water,
sanitising them on the outside, and dropping them into the
fermenter. Alternately, you can drape a wet towel or T-shirt
around the fermenter and direct the breeze from a fan at it
(this technique is great for unexpected heat waves as well).
When the temperature is below the recommended maximum in your
instructions, go ahead and pitch a fresh package of yeast.
If the temperature of the must is below 18°C (65°F), warm it up
by wrapping the fermenter with a heating belt or by other means
of direct heat. Do not set it on a heating pad or blanket: this
concentrates the heat and can cause electrical damage, or even a
fire (not to mention what it would do to the wine). Most of the
time, the yeast will recover and begin fermenting on its own
within 24 hours, but if not, double-check the temperature of the
must, and pitch another package.
There is a definite window of opportunity for correcting the
must temperature or adding a missed package of yeast: if you
catch a non-fermenting kit within four days, you can probably
get it going without repercussions. Keep in mind, however, that
unprotected grape juice is an excellent growth medium for all
kinds of bacteria. If the must smells sour, or looks mouldy (see
the sections below on clarity and odour problems), you are
probably out of luck. In any case, monitor your fermentation for
signs of contamination during the rest of the process.
If you have added the yeast, the temperature is fine, and it is
still not fermenting within 24-48 hours, have a careful look for
the additive packages that came with the kit. If you have
accidentally added the stabilisers to the kit, you may have a
terminal problem on your hands.
If you have only added the sulphite, sometimes a very strong
yeast starter culture can overcome moderate levels of free
sulphur dioxide. Start a package of yeast in a quart of
commercial apple juice heated to 24°C (75°F), along with a
teaspoon of yeast nutrient. Shake the juice and nutrient mixture
before adding the package of yeast, as a little dissolved oxygen
will help the yeast get started. After 24 hours, or the onset of
very vigorous activity, pitch the entire quart into your must.
Do not worry about changing the flavour; any change would not be
significant, and a small flavour change is less important than
getting your must started as soon as possible. If you have added
more than 50 parts per million (PPM) of extra sulphite (6
grams/a half-teaspoon per 23 litres/6 US gallons), there are
some things you can do to lower the sulphite content. Look in
the section on odour problems, below.
Another good restarting techniques is to take a wine from
another kit that is ready to be racked from the primary
fermenter to the carboy, and harvest the yeast sediment
remaining after the wine has been racked. By far the best way to
do this is to leave the yeast sediment in the primary fermenter
and pour the non-fermenting must in on top of it. Finish up with
a good stir, to get all of the yeast cells into suspension. This
will be a rich source of very active yeast, and should restart
just about any fermentation it is added to.
If, rather than adding the sulphite, you have mistakenly added
the sorbate package included in the kit, discard the wine.
Sorbate prevents yeast breeding, and virtually all efforts at
starting fermentation in the presence of sorbate end in failure.
If you have avoided all the above conditions, and your wine
still would not ferment, your yeast may have been inactive; a
fresh package should get things on the road. Make sure it is the
same variety and type of yeast included in the kit, or you may
not get exactly the results intended.
One thing that may seem like a good idea, but actually does not
work with wine kits, is adding extra yeast nutrient. Winexpert
adds very nearly the maximum amount of yeast nutrient a kit can
handle. It is not going to be a low-nutrient situation that
hampers your fermentation, and extra nutrient not used by the
yeast will stay behind in the wine, and will leave a
Wine Ferments Too Quickly/Slowly
If your wine ferments to dryness in less than half the time
required in the instructions, your temperatures may be too high.
Try the wet towel trick described above, to cool it down. The
trouble with hot fermentation is that yeast tends to generate
its own heat after a certain point, and you could have a
heat-related yeast die-off and a stuck fermentation later. If
your wine ferments to dryness in less time than specified in the
kit instructions, please wait the minimum amount of days
indicated in the instructions before racking to the secondary
fermenter. For example, if the instructions say to wait 5 to 7
days, until the gravity is below 1.020, and you achieve 1.020 on
the third day, cool the fermentation down to the temperature
specified in your instructions and wait until day 5 before
racking. This will ensure that an appropriate amount of sediment
is left behind in the primary, and could prevent problems with
fining and clearing later.
Once in a while we see a kit that has been racked to the primary
too soon, while having a large amount of oak chips still in
suspension. These can collect in the airlock and block it off,
causing pressure to build up, until suddenly the whole thing
If you do find your wine shooting out of the airlock, you have
racked it into the carboy too soon. Rack it back into the
primary and wait for it to hit the correct gravity. Do not be
fooled if it calms down immediately after racking. All that has
happened is that the CO2 has been knocked out of solution by the
agitation of racking, but the wine will soon be foaming
If your fermentation is proceeding too slowly, try warming your
must up to the recommended temperature, and practice patience.
Do not rack the wine on day 7 if the specific gravity is higher
than recommended in the instructions. Wait for the appropriate
One thing we frequently see hampering fermentation schedules is
repeatedly fluctuating temperature. Most of us never think about
it, but when we leave for the day we turn the furnace off,
dropping ambient temperature in our fermentation area, and when
we come home, we warm our house up. This drives yeast crazy, and
it can often cause it to go dormant, while it waits for more
favourable conditions. You may need to isolate your fermenter in
an area with a more steady ambient temperature.
Wine Won't Quit Fermenting
Sometimes a carboy will continue to bubble and bubble, long
after it should have stopped. First of all, check your specific
gravity. If it is high, give the wine a good stir, make sure the
temperature is at the high end of the specified range. Then
practice patience yet again.
If the SG is in the right range, as listed in the instructions,
you may be experiencing one of two phenomena. First, your wine
may actually be finished fermenting, but due to changes in
temperature or barometric pressure it is out-gassing carbon
dioxide at a rate that looks quite like active fermentation.
This could be exacerbated if your wine fermented quite slowly
(as in a cool fermentation), and is saturated with CO2.
How this works with temperature: CO2 is soluble in a liquid
solution in inverse proportion to the temperature of the
solution. When a can of soda is ice-cold, it barely hisses on
opening. When it is hot, it gushes from the can as the trapped
CO2 tries to exit as rapidly as possible. If your wine finishes
fermenting cool, and then warms up, it may expel the gas quickly
enough to mimic active fermentation.
How this works with barometric pressure: The sixty-mile deep
layer of air above you presses down and keeps the pressure on
you and everything around you at about 15 pounds per square inch
at sea level. This pressure of air also squeezes the carbon
dioxide in solution in your wine kit. Under high pressure
conditions (clear skies, sunny) the CO2 stays in solution. If
there is a change in the weather (dropping barometric pressure,
cloudy skies or rain) then the pressure lessens, and gas comes
out of solution, again mimicking active fermentation.
The other possibility is that the wine is being fermented by an
organism that can continue to access nutrients long after the
cultured yeast has finished. This could be random bacteria from
the environment (most commonly a lactic acid bacteria, like a
spontaneous malolactic fermentation) or a mutant or indigenous
yeast. In this case, when the wine has hit its target gravity,
and the requisite number of days have passed, it is imperative
that you proceed with the stabilising and clearing procedures in
the instructions. By stabilising in a timely fashion, and at the
correct specific gravity, you will prevent organisms from doing
any significant damage to the kit.
Wine Won't Clear
First of all, if your wine is cloudy, do not try to bottle it,
because it woould not clear in the bottle. In fact, you had have
wasted your time, since any extra treatment you do to clear the
wine would require you to dump out all the bottles, process the
wine, and re-bottle.
Secondly, do not filter the wine to clear it. Filtering is only
good for clearing wines that are already almost completely
clear. Fining agents still in suspension would quickly block
your filter pads, and those that madke it through would simply
show up as sediment later on. So this would be another waste of
time and money.
Your first step, if your wine has not cleared, should be going
back to the instructions and carefully reviewing them to be sure
you followed the fining procedures exactly. Winexpert kits want
you to add bentonite on the first day, while others want it on
the 20th. Some kits must be racked prior to fining, and some
must not be racked or the finings would not work at all. But you
will notice that the instructions regarding fining all contain
the same phrase:
Stir the wine vigorously
Which actually means, really, really, really vigorously. In
order for the finings to have the proper effect on the wine, it
needs to be free of carbon dioxide. If it is not, the fining
particles will attach to the bubbles of CO2 and float back into
suspension, over and over again, so that nothing settles out. So
stir the wine until it stops fizzing. You may help this process
if you warm the wine to the upper end of the specified
temperature range; remember that CO2 is soluble in a liquid
solution in inverse proportion to the temperature. When the wine
is warm, it will be much easier to de-gas.
This leads to the next step: check the specific gravity. If the
wine had not finished fermenting before you added the finings,
you will have no option but to have to wait until it does.
Nothing you do will influence the clarity until the yeast is
finished fermenting all available sugars in the juice.
If all of the above suggestions are in order, double-check the
instructions regarding temperature. While some fining agents
work very well under cool temperatures (bentonite, kieselsol,
etc), others (chitosan, isinglass) stop working at all below
specified temperatures. Many grape winemaking textbooks advise
lowering temperature to help the finings work but make sure this
agrees with your instructions before you do cool the must down.
So, if your gravity is correct, and you have stirred the wine
sufficiently, and you have got it at the right temperature, the
best course of intervention is simply to wait an extra week and
see if it clears up on its own. The principle of least
intervention applies to all fining activities: try to get the
most effect with the least amount of added finings and effort.
However, if weeks of patience do not seem to make a difference,
you can probably add an extra dose of finings. Use the same
fining agent used in the kit, at a rate of 50% of the original
dose. If that turns out not to be an option, the fining agent
Sparkalloid is an excellent choice. It is a little complicated
to use, but the combination of carageenan proteins and
diatomaceous earth makes it a very effective clean-up fining.
Use sparingly and follow the package directions precisely.
If you do wind up stirring extra fining agents into the kit, be
sure to increase the sulphite levels to match the extra
processing and handling. As a rule of thumb, you can add an
extra 1.5 grams per kit (one-quarter teaspoon) to offset any
oxidation from the handling.
Wine Clears, But Goes Cloudy in the Bottle
If your wine seemed clear in the carboy, but after bottling
showed a haze or sediment, you have one of three problems:
Fermentation Not Finished
You can determine if the wine is continuing to ferment in the
bottle by taking a sample and checking both the specific gravity
and the level of CO2. If the specific gravity is higher than
that recommended in your instruction for bottling, and it has a
significant amount of CO2, you will need to un-bottle all of it
and let it finish fermenting.
This is especially important if your wine is stored inside your
house or over a carpet. You could discover that your bottles
have become a bunch of miniature wine-volcanoes popping corks
and spewing red wine all over your rugs. Or, even worse, you
might find that your batch become thirty glass hand grenades
ready to shower your room with debris and even do you some
If the specific gravity is at or below the levels recommended in
your instructions, but the wine is fizzy with CO2, and hazy, you
may have a microbial infection in the form of a wild yeast or
spoilage organism. There are thousands of potential culprits,
from lactic acid bacteria (spontaneous malolactic) to
acetobacter (vinegar) to air-breathing mutant yeast (candida
vini). All will have the same characteristic, the ability to
ferment your wine after it has achieved what should be your
terminal specific gravity. In this case you will need to
un-bottle it all, re-stabilise it with more sulphite, and filter
it. It will need to remain in the carboy until you are
completely sure it will not ferment again in the bottle.
Protein haze is by far the most common of the three scenarios.
Sometimes a fining agent will fail to clear all of the big
proteins in a wine kit, or in some cases, traces of a
protein-based fining agent (gelatine, isinglass, etc.) will stay
in solution. When the temperature of the wine changes, these
proteins become visible as a haze. As it warms up again, the
haze usually disappears. If you are familiar with beer making,
you will recognize this as chill-haze.
Proteins are usually taken care of with the bentonite included
in most kits, but if you do have a protein haze, a small
addition of bentonite should take care of it. Try adding 15
grams to the kit (about three teaspoons). Follow the bentonite
instructions for rehydration, and add to the kit. Wait two weeks
and check again for cold stability.
Another solution to this problem is cold filtering. If the wine
is mostly clear at room temperature, but it clouds when it is
cold, you can chill the entire batch, and while it is still
cold, filter the haze out. Note that this will not work if the
wine contains significant amounts of solid material or sediment.
Something is Floating in the Wine
Lumps on Top
During the early stages of fermentation, yeast can sometimes
clump together and float on top of the must. And occasionally
mould can form on top of the wine, showing up as small,
papery-looking dots or circles. To discern between yeast and
mould, take a sample of the floating material and rub it between
your fingers. Yeast smears like yoghurt or sour cream. Mould
will roll up like rubbery paper, and would not smear at all,
remaining discrete in your grip.
If it is yeast, ignore it. Sometimes yeast simply does float
around at the top of the must this way. On the other hand, if it
is mould, you need to carefully assess the wine. If the mould
came out of the bag when you made the kit, you should carefully
document the kit serial number, grab a sample of the mould, and
call your sales rep for help. Winexpert warrants all kits
against such defects, but do not skip the sample and serial
Because of the way the wine is packaged, through a sterile-fill
pasteurising head, it theoretically goes into the bags free of
organisms. But certain environmental moulds are actually
thermophillic, meaning they do not bloom until after they have
been heated beyond a certain point. You see this phenomenon in
some trees that would not release seeds from their cones until
after a forest fire has cleared the underbrush and roasted the
cones to fruition.
Similarly, thermophillic organisms can survive the pasteurising
process and show up in your wine a few weeks after packaging.
But do not panic; the failure rate from this sort of mould is
very low indeed. We track this very keenly, so take a sample and
contact us with the serial number and sample.
But if you see something floating on your wine after it has been
stabilised and fined, it could again be clumped yeast, meaning
you had stir harder to release CO2 so the clumps will sink. Or
it might be an aerobic organism, like mycoderma or acetobacter
(see the sections on films below). It would not be mould in this
case, though, because mould can not grow in wine once the
alcohol level rises above 3%.
Film On Top Of Wine
Film organisms like mycoderma and acetobacter only grow in
aerobic, or oxygen-rich environments. This points back to
carboys that were probably not topped up according to
instructions, or wines that do not contain sufficient sulphite.
Mycoderma is actually a species of yeast (Candida vini) that
breathes air. If you detect it soon enough, you can sometimes
treat the wine with a measured dose of 50 PPM of sulphite (6
grams, or a half-teaspoon of sulphite powder), followed by
racking to get it off of any mycoderma sediment. Top the wine up
to the neck of the carboy, use a solid bung, and taste the wine
after a week to see if you caught it in time.
You may wish to re-test the wine for sulphite level, and filter
it to keep it stable. Then go through all of your equipment and
sterilise it by soaking it in a chlorine solution, and scrubbing
with plenty of elbow grease. Check all of your other wines,
being careful to sanitise your wine thief and sample jars
between wines. Mycoderma easily spreads to other wines, and is
difficult to get rid of.
Here we should mention something about chlorine sanitising
solutions: the most common one is a pink, chlorinated-phosphate
detergent that Winexpert sells as Sparkle Brite. Originally a
product from the dairy industry, it is also used for sanitising
milk-processing equipment. It not only cleans effectively, but
also destroys the physical body of a spoilage organism through
the action of the chlorine. Mere sulphite or detergent can not
accomplish this, and infections like mycoderma or the other ones
listed below are serious enough to warrant a take-no-prisoners
effort at sanitation. Be careful to follow the package
instructions for use, and keep the product out of contact with
metals like aluminium (which can produce irritating gases) and
stainless steel, which chlorine can pit and etch.
Some people see a film on their wine and think that they have a
sherry or flor yeast. This is a type of yeast that behaves as
strangely as its cousin mycoderma, utilising oxygen and leaving
a film (or flor) on top of the wine. As it works, it can drive
the alcohol content of the wine to 20% or higher, and leaves it
with a nutty, delicate flavour described as rancio by sherry
makers. But it is very unlikely that the film you see is
actually flor. It grows under an incredibly narrow range of
conditions: temperatures in excess of 38°C/100°F, lots of
dissolved oxygen, no sulphite and a huge culture of the proper
yeast strain. So you will probably never see it.
Swirly Haze in Wine
Characterised by a milky, cohesive swirl in wine, acetobacter
consumes alcohol and leaves you literally with a sour taste in
your mouth. It breaks alcohol down into acetic acid and
associated ketones, esters and aldehydes, giving wine that
distinctive vinegar odour and back-of-the-throat tang, dropping
its alcohol content and utterly ruining it forever. It can
manifest itself as a swirly-looking ghost in the wine, known as
mother of vinegar.
Unfortunately, if this is the problem with your wine, it can not
be saved. Nor can you use the vinegar for anything, since the
kind of vinegar that wild actobacter makes tastes more like
nail-polish remover than salad dressing. Sanitise all of your
equipment intensely, all at once, with chlorine-based solutions.
When making a wine kit, the solution to acetobacter is
preventive: top up your carboys, make sure the airlocks and
bungs are secure and full of water or a sulphite solution, and
use the recommended level of sulphite in your kit.
The fruit fly is the primary carrier of acetobacter. But by
following several rules of thumb, you can reduce the possibility
that this problem will affect your wine. Start by wiping up all
spilled wine and juice, treat all your surfaces with sulphite
solution, and do not keep bananas in the winemaking room. If you
do get a fruit-fly infestation during a warm spell, get some
food-grade insecticide. This is based on pyrethrin (derived from
chrysanthemum oil) and is sold by food service suppliers and
sometimes by hydroponics supply shops. One popular brand is
Gard-Mist. It is safe for use in food preparation areas, and it
is not very smelly. Read the label before using.
Wine Looks Like Ropey Goo
Another strange phenomenon in wine's appearance is rope, or
graisse. The yeast exudes a mucous-like polysaccharide compound
and thickens the wine. In extreme cases, you can actually use
your finger to scoop out a thick ribbon of wine that looks like
rope! This condition, while fascinating, is rare even in the
worst winemaking conditions. If somehow you do discover this
phenomenon in a wine kit, throw your wine away, discard your
equipment and start over. There is simply no cure for this
Kit is Darker/Ligher Than Expected
Wine kit manufacturers are in an odd position: they make a
packaged food out of a variable agricultural product. In this
respect they are like producers of bread or pasta, who face
harvest differences from year to year (e.g. wheat having higher
or lower protein content due to local growing conditions). Both
of them blend raw materials (wheat, or grapes) from different
areas to try to achieve consistent quality.
However when all of the grapes in a kit come from a specific
area, as they do in Limited Edition, Vintners Reserve Passport,
Selection International or Selection Limited Edition, it may not
be possible to completely blend away the colour and flavour
differences. Commercial wineries acknowledge this, and celebrate
the different harvests by doing vintage tastings. Kits, however,
will vary a bit from year to year, and unless the colour change
is marked by some other change (such as a loss of aroma or
bouquet) you may not want to do anything to change it.
There are colouring products on the market, such as Grapeskin
Extract, Oenocyanin, Exberry, etc, which can be used to darken a
red wine. If you must use them, follow the package directions,
but keep in mind that they are not very stable colours, and
could combine with any proteins or melanoidins in the wine and
fall out of suspension later on, leaving a deposit in the
Philosophically, Winexpert is opposed to darkening kit wines
with exogenous colouring agents. High-quality kits will have an
appropriate color that would not require fiddling, and are as
dark as or darker than good commercial examples of the wine.
Also, keep in mind that dark colour is not necessarily a sign of
high quality. Pinot Noir kits can be a delicate ruby color and
still deliver wonderful flavor and quality. Having said that, it
could happen that a kit is mislabelled, and if you get a white
wine out of a box clearly labelled as red, you need to contact
your retailer immediately.
It hardly ever happens that a kit is darker than expected, but
if it is, double check with your retailer to make sure you got
what you were asking for. If it is the correct style, but still
seems too dark, you may wish to blend it away into a lighter
Pink Wine is Orange
Blush wines are actually quite difficult to produce, and
commercial wineries have spent literally millions of dollars
trying to figure out how to keep the color in their blush. The
kind of color compounds that give a blush or a white Zinfandel
(or Merlot) its lovely pink color are very unstable. They lose
their purple-pink hue over time and change to a reddish-brick
pink. The French call this color l oeil de Perdrix (eye of the
partridge) and it almost looks like the color of salmon flesh.
This change is not a sign that the wine is oxidising or
spoiling, merely that the colours are going through their
natural evolution. Red wines do the same thing, but they have
much higher levels of color, and more importantly they have
higher levels of tannin and polyphenolic compounds which
stabilise the color. Again, unless this color is accompanied by
definite off aromas and flavors, it is not a sign of low
White Wine is Brown, Red Wine is Brick-Colored
While well-aged examples of white wine can be deep golden, or
Icewine a gorgeous amber, or sherry a lovely tawny-toast colour,
brown wine is usually a sign of advanced oxidation, and is
usually accompanied by a sherry-like smell due to acetaldehyde
production. When terminally advanced, this sherry smell goes
from acetaldehyde to acetic acid to ethyl acetate, the vinegar
and nail polish remover aromas described below.
The best treatment is prevention, so follow your kit
instructions for racking, topping and sulphite use. Severe
oxidation is always preventable.
But if you get caught out, in early stages you can treat the
wine first with a strong dose of sulphite (50 PPM), and then
with a compound that removes oxidised melanoidins (colour
compounds). The best of these is Polyclar (food grade
Polyvinylpolypyrrolidone or PVPP, a type of powdered nylon). Use
according to package instructions, usually stirring in 1 to 2
grams per litre (one to two ounces of powder per kit). This
amount may seem high to people who have used Polyclar for grape
or fresh juice wines, but experience with kit wines has shown
they take significantly more treatment to remove oxidised
compounds. Polyclar requires repeated stirring over a period of
hours, as it is only effective when in contact with the wine,
and it settles out rapidly. After stirring and settling, filter
the wine and adjust your sulphite to 50 PPM again.
Polyclar can diminish aroma compounds (sometimes it is used for
this very purpose, to remove an undesirable aroma) and can
completely de-aromatise a wine, so you may wish to do a trial on
a small sample of your oxidised wine to determine if it is
actually an improvement.
Polyclar can also indiscriminately remove polyphenolic compounds
(tannins) and desirable melanoidins. For this reason it is much
more damaging to red wines, and a dose can strip a bricky-red
wine to salmon-y pink, and remove enough of the tannins to leave
it flabby and soft. But a small trial will tell you if it can
help the wine without stripping it too much.
It is possible to re-correct the colour and flavour of a
Polyclar stripped red wine with the addition of oenocyanin
(grapeskin extract, etc.) and tannin, but wines treated this way
always have an unsatisfactory manipulated taste, and rarely age
Deficiencies in aroma or faults come in the following varieties
in wine kits:
Wine Smells Like Matches
Your wine may have too much sulphite, which is characterised by
a 'burnt match' or 'sulphur/volcano' smell, often accompanied by
a tickling in the nose. However, the true level of sulphite ca
not really be determined without a proper sulphite test. Until
you have had your wine accurately tested, do not attempt any
correction of the sulphite level.
Minor excesses of sulphite (an extra 10 or 25 PPM) can be driven
off by stirring small amounts of oxygen into the wine,
effectively oxidising the free sulphite into bound sulphite,
taking it out of action. You can stir air into the wine with a
spoon, rack it with plenty of splashing, or bubble air into it
with a brand-new, sanitised fish tank aerator for a short period
of time. As always with such operations, test, adjust and test
again to make sure you accomplished your goal.
Larger amounts of sulphite (up to an extra 50 to 100 PPM) can
sometimes be treated with hydrogen peroxide addition. Hydrogen
peroxide is a very potent oxidiser. In high concentration, it is
used as part of the fuel mixture in rocket engines, oxidising
the fuel so rapidly as to resemble an explosion. It does the
same thing in wine, oxidising the sulphite, taking it out of
For every 10 PPM of sulphite to be removed in 23 litres (6
gallons) of wine, add 4.2 ml of regular drug-store hydrogen
peroxide. You must use a brand-new bottle of 3% USP-grade
hydrogen peroxide, measure with a syringe to get accurate
results, and above all, test before and after your adjustment,
to make sure you have hit your precise target.
The big problem with using hydrogen peroxide is that it is very
touchy. If your calculations are off by even a few drops, you
will not only reduce the sulphite but will also strip its
protective power from the wine and oxidise it beyond redemption.
If this does happen, your only recourse is to discard the wine.
In the case of massive overdoses of sulphite (in excess of 100
PPM) there is no answer. Hydrogen peroxide does not make the
sulphite disappear, but simply shifts it into another form, and
too high a concentration of the bound form is not acceptable for
Wine Smells like Chemicals or Plastic
If you introduced any of your cleaning chemicals (chlorine,
detergent, caustics, free halogen sanitisers such as Iodophor)
into the wine, you should discard it immediately. While small
amounts of these products may or may not be harmful to your
health, there is no way to be sure, and you are better safe than
If you tried to ferment your wine in a non food-grade fermenter,
you may have a real problem on your hands. In addition to
causing odd plastic aromas in the wine, non food-grade buckets
and pails use volatile chemicals and sometimes heavy metals such
as antinomy, arsenic and lead, to keep the plastic pliable and
soft. They may also contain UV blockers that are toxic. The
alcohol in the wine will leach these out, and could seriously
jeopardise your health. Discard the wine and purchase some good
food-grade wine-specific equipment.
Wine Smells Like Sherry or Nuts
These smells mean that your wine is oxidised. See the treatment
recommendations for browned wines in the section, above, on
Wine Smells Like Rotten Eggs
Most yeast produces a small amount of hydrogen sulphide (H2S)
during fermentation, giving off a whiff of rotten-egg smell.
Certain yeast are famous for producing large amounts of this
aroma, the Montrachet strain being particularly bad. However, an
excess of H2S is usually a symptom of low nutrients in the must,
or too high a level of solid grape material. Since these
conditions do not apply to wine kits, this problem is pretty
However, if you do experience the problem, it can sometimes be
cured by aeration, like the treatment, above, for small amounts
of excess sulphite. This will drive the aroma off. If the smell
is worse than a whiff, though, the fix could be to treat the
wine with copper, either in the form of metallic copper (a
handful of sanitised pennies tossed in the carboy) or with a
product called Cufex, which is a copper sulphate compound. But
the problem with this is that even in small amounts, copper is
toxic to humans, and the treatment requires laboratory testing
and measurements for safety.
However, there is a brand-new treatment available that is both
easy and safe. It is a product called Bocksin, which is made by
the German firm ERBSLÖH GEISENHEIM. Related to the fining agent
silicon dioxide (kieselsol), this product is stirred into the
wine in the amount of 30 ml per 23 litres (6 gallons). It
immediately bonds to the hydrogen sulphide and removes the
aroma. Because it is formulated like silicon dioxide, it acts
like a fining agent, bonding to proteins in the wine, settling
out and leaving sediment. It may be necessary to rack and/or
filter the wine after using Bocksin.
However, there may come a point where the hydrogen sulphide will
chemically change to another compound called mercaptan. This is
the same compound that is added to propane and natural gas to
give it the distinct skunk aroma that alerts people to gas
leaks. Once it has settled into a wine, there is no treatment.
Wine Smells Like Yeast or Bread
Actively fermenting wine will have a faint yeast smell, but if
the wine in the carboy takes on a heavy smell like bread, or in
some cases soda crackers or even brewer's yeast, you may be
smelling the beginnings of autolysis.
Autolysis is the physical action of inactive yeast cells
disintegrating and releasing their internal contents into the
wine. Essentially, the dead yeast rots and decomposes. Because
the material they release is rich in amino acids, it has a
distinctive odour. The good news is that autolysis takes many
months to occur at room temperature, and even longer at cool
temperatures, and in any case only happens in the presence of a
visible sediment of yeast.
If you follow the instructions in the kit with regards to
racking, fining and stabilising, you should never see autolysis
in any of your wines. But if you miss racking a kit for an
extended period of time, your wine may be vulnerable. If you
catch it at the first sign, quick racking and sulphiting can
prevent the autolysis from overwhelming the wine, but if it has
already progressed to the point where it can be strongly
detected as a brewer's yeast smell, there is no cure. In
addition, because of all the amino acids in suspension, the wine
will be far more susceptible to infection by spoilage organisms.
Your wine is infected with acetobacter. See the bad news in the
Color and Clarity section, above.
Wine Smells Like Dead Trout/Rotting Geraniums
Unfortunately, this problem is not as uncommon as we had like to
see in wine kits. When it is full-fledged, this condition can
wrinkle noses at one hundred yards, and once smelled is never
The compound Hexadienol causes the odour. It is produced when
lactic bacteria consume the sorbate in the wine kit. These
bacteria are present wherever human beings live, and are on
virtually every surface as well as being airborne. They are
easily suppressed by the sulphite included in a wine kit.
However, if the sulphite level falls, either through oxidation,
or because the winemaker did not add the correct amount, they
can infect the wine.
Normally, lactic bacteria will produce low levels of off-odours,
sometimes described as cheesy, mousy or musty. Most people will
never notice them. However, in the presence of sorbate, which is
included in wine kits as a stabiliser, they produce the stunning
aroma of fermented trout and flowers. This is a terminal
condition, and the wine must be discarded.
The best way to prevent this is to make sure you are adding the
full amount of sulphite included in the kit. If you are adding
extra rackings to the processing of the kit, or if you are
storing the wine for long periods of time, make sure to top up
your carboys and monitor your sulphite levels.
Also, if you choose not to add the sulphite to your wine kit,
you must not add the sorbate either, lest disaster result.
Without the sulphite to suppress them, lactic acid bacteria
could have a field day with your wine, and with the sorbate.
Wine is Stinky When Poured
When young wines are put into the bottle, they sometimes carry a
residual aroma of fermentation with them, often a hint of
hydrogen sulphide or simply a slightly yeasty character. This
usually dissipates with time, but if you are drinking your wine
young, then decanting it before serving, or swirling it in the
glass, will often drive off most of the aroma. If the stinkiness
persists, your wine may have hydrogen sulphide or excess
sulphite (see above for how to deal with these). You should also
ensure that your wine is completely de-gassed before bottling.
This will cut down on any off aromas carried into the bottle.
If some of your bottles of wine have an aroma like a wet mouse
or maybe an old mouse nest, but others seem normal, you may have
a trichloranisole contamination from your corks. Trichloranisole
is a combination of a mould from the lignin, or fibrous part of
the cork, and chlorine, used in bleaching and sanitising the
corks after harvest. It is a persistent problem in the cork
industry, and one all winemakers have to live with, even if they
use the highest quality corks. There is no cure but to open
Trichloranisole contamination can be entirely avoided through
the use of synthetic corks.
The Bright Side
The good news in all of this is that most of these problems are
actually very rare. Of the hundreds of thousands of wine kits
sold every year, we see very few cases of real defects in
processing. Winemakers generally tend to be pretty savvy and
With good sanitation, accurate measurements of temperature and
gravity, and detailed record keeping, you should never see most
of these problems. But if you do, again, do not panic: most of
the common conditions are easily fixed. Check out your options,
and if you get stuck, call your retailer for back up. They
should be able to help you get back on the right track.
Courtesy of Winexpert