sábado, 6 de octubre de 2012

How to Make Homemade Wine


The beginner can start with utensils that are readily available in the kitchen, together with one or two extra, but essential, pieces of equipment, such as a fermentation jar and fermentation or air lock.

Fermentation is the most important process in winemaking. Yeast is a fungus which grows in the presence of sugar, converting it into alcohol and carbon dioxide. Vigorous bubbling is the sign that fermentation has started, and the colourless carbon dioxide gas can be seen escaping as bubbles through a water-filled fermentation lock. One of the pleasures of winemaking is to watch the daily progress of a gallon of the fermenting liquor, until the rhythmic air lock bubbling slows and eventually ceases when fermentation is complete.


There is no need for the beginner to buy lots of expensive equipment straight away but one or two inexpensive items will be needed. As a enthusiasm and experience develop, extra equipment will undoubtedly be required. Any equipment that you do need to buy can be obtained from most chemist’s shops, many chain stores, some health-food shops, and, particularly, from one of the specialist home brewing and winemaking retailers that can now be found in most towns around the glove.

If there is a ‘golden rule' for winemaking, it must be to ensure that all utensils are always clean and free from bacteria. To achieve perfect cleanliness you must wash out, or soak, all your winemaking equipment in a sulphite solution by dissolving either two Campden tablets or 5 ml/1 teaspoon of sodium metabisulphite powder in 600 ml/ 1 pint of water. The solution is an effective killer of the vinegar-producing bacteria carried by the ever present fruit—fty (Drosophila melanogaster) which is probably the winemaker’s most persistent enemy.

You should try to obtain all of the following utensils which are essential for successful wine-making.

- Boiling pan: You will need some sort of pan for boiling water. It should be large enough to hold at least 4.5 litres / 1 gallon of liquid, although you will find that a larger vessel is more convenient to work with. A large preserving pan or saucepan may be used, but whatever its size, it is most important that the container should be made of stainless steel, aluminium, or enamel ware. You should not use equipment made of any other metals at any stage of your winemaking because they may impart unpleasant flavours to the wine or even deposit poisonous substances.

- Fermentation vessel: High-density polythene or polypropylene buckets are ideal for mashing ingredients and initial fermentation purposes, although they should be white or translucent because some buckets or dustbins are not suitable for holding food. Specially designed fermentation bins are widely available. These are usually supplied with a tighdy fitting lid which often has a hole for a fermentation lock, to avoid contamination from airborne bacteria. These usually come in two sizes, 23 litre/5 gallon and 9 litre/2 gallon and which one you choose will depend on how much wine you plan to make in one go. Large earthenware, plastic or glass containers are also suitable, but don’t use earthenware unless you are sure that the glaze has no lead in it. As they will be used for mashing and soaking the fruit or berries to extract their flavour, it is essential that the containers are covered to keep out bacteria. Polythene sheeting placed over the top of the container and tied tightly is extremely successful. This allows gas to escape while protecting the liquid from contamination.

- Fermentation jar: A couple of 4.5 litre/1 gallon glass fermentation jars are essential and these are available in both clear and coloured glass. The coloured glass jars are used mainly to avoid the loss of colour from red wine, which sometimes occurs if it is left in daylight for too long. Both types of jar have a narrow neck into which a cork or rubber bung can be fitted securely.

- Fermentation lock: There is a variety of locks to choose from, made either from glass or plastic. The plastic ones, of course, are less likely to be broken.

The fermentation lock is a simple device which allows gas to escape from the fermenting wine while preventing air or fruit flies from entering the fermentation jar.

Half fill the lock with water, containing a small amount of sulphite solution or an eighth of a Campden tablet. This ensures that, even if fruit flies get into the water in the fermentation lock, it will not become infected, and the risk of any harmful bacteria reaching the fermenting wine is reduced. A small plug of cotton wool placed in the open end of the lock also keeps out the fruit flies.

The fermentation lock is held firmly in the neck of the fermentation jar by a large rubber bung or cork with a hole in the centre. If you use a cork, you must make sure that it does not dry out and shrink or the air-tight seal will be broken.

- Miscellaneous: A large polythene funnel-at least 15 cm (6 in) in diameter—is extremely useful, and no doubt will be found in your kitchen, as will wooden or polypropylene spoons, scales for weighing ingredients, and a clear plastic or glass measuring jug.

During the course of making wine, you will need to strain the liquid. A nylon sieve is the most convenient utensil for removing the larger particles of unwanted deposits, but for straining off finer particles, you should use a jelly bag or a fine-mesh nylon straining bag.

When fermentation has finished, the wine will stop bubbling and begin to clear as all the sugar will have been converted to alcohol and the specific gravity of the wine will be close to 1000 in ‘The hydrometer’. This should take two or three weeks. Then you will need to siphon off the dear wine from the deposit of the dead yeast cells which have fallen to the bottom of the fermentation jar. You should avoid disturbing the waste material, and you can easily make a simple siphon from a length of plastic tubing specially made for the purpose, although you can also buy a more sophisticated siphon incorporating bellows to start the initial flow of liquid.

A thermometer is a handy instrument to have available, and will take the guesswork out of controlling the correct temperature for adding yeast to the liquid and keeping the fermenting wine at its maximum efficiency. It is best to buy a thermometer that has been specially designed for brewing or winemaking. They are usually about 30 cm (12 in) long to give a clear reading and are filled with alcohol rather than mercury so that the wine will not be ruined if the thermometer is broken. If this should happen, the glass will safely remain in the dead yeast cells and the wine can be siphoned from it. Thermometers may be graduated in either Centigrade or Fahrenheit (or both) and range from -10°C (14°F) to 110°C (230°F).


The fact alcohol produced by the fermentation of sugar solution by yeast under favourable conditions has been known and utilized for centuries.

Winemaking was usually a process of guess-work, which all too often resulted in a product of dubious strength and quality, and frequendy in complete failure.

It is only comparatively recently that fermentation has been widely understood, allowing the amateur winemaker a degree of control over the craft that was once impossible to attain.

In home winemaking, fermentation is a complex process in which the microscopic cells of yeast thrive and reproduce themselves on the liquid sugar and fruit juice mixtures, know as must. Alcohol is produced by this fermentation and the liquid eventually becomes wine. These living yeast cells have to multiply rapidly to produce the millions needed to convert all the sugar present into alcohol.

As the yeast begins to multiply, it splits the sugar into carbon dioxide and alcohol. A steadily bubbling fermentation will, therefore, be producing alcohol at roughly the same rate as carbon dioxide gas is escaping from the mixture.

It is not at all difficult to make a must ferment and become alcoholic, but several factors determine the quality, strength, and flavour of the finished wine.

- Yeast: There are many types of wine yeast available now, some of which will produce a wine with the characteristics of a commercial product such as Bordeaux, Sauternes, Port, and Burgundy. Obviously, these have to be used in conjunction with ingredients that are sympathetic to their original counterparts.

Wine yeasts are available from your home wine-making stockist in many forms, the most common being dried granules or tablets, although liquid yeasts and cultures are also quite suitable. Some wine yeasts have been developed to allow a greater proportion of alcohol to be produced in the wine than is usually obtainable. You should never be tempted to use brewer’s or baker’s yeast for wine-making.

- A starter bottle container: Your must will begin to ferment more quickly and reliably if you start the yeast fermenting in a starter bottle before it is added to the must. Prepare a boiled solution of 300 ml (1/2 pt) of fruit juice, 25 g (1 oz) of sugar, a pinch of citric acid crystals, and a pinch of winemaker’s vitaminized yeast nutrient. The addition of the acid and the nutrient should ensure that the conditions are ideal for the yeast to become activated. When the liquid is luke-warm, at about 21 °C (70°F), add the sachet of granulated dried yeast or the yeast tablet following the instructions on the packet. Pour the solution into the sterilized bottle, plug the botle with cotton wool and leave it to stand in a warm place. After a while the liquid will begin to bubble, and it is then ready to be added to the must to produce rapid fermentation.

- Yeast nutrient: The addition of 5 ml (1 tsp) of yeast nutrient to the must ensures that there is enough nourishment for the yeast in the form of minerals, vitamins, and salts.

Grape juice is the perfect medium for fermentation to take place in, but a proprietary yeast nutrient will provide the correct amount of ammonium sulphate and phosphate in musts lacking these elements.

Vitamin B is also helpful in producing a vigorous fermentation, and is usually found in yeast nutrients, although you can also add vitamin B tablets from time to time to enliven the fermentation.

- Temperature: It is most important to maintain the correct temperature in the must because yeast will be killed by too high a temperature and its propagation slowed down or stopped by too low a temperature. The ideal range is between 19°C and 24°C (66-75°F), although a few degrees either way will be tolerated.

Try to make sure that the temperature remains steady by placing the jar out of harm’s way in a warm kitchen or an airing cupboard.

- Acidity: For a vigorous fermentation to take place the liquid must should be slightly acid. Many fruits contain enough acid naturally, but you will need to add acid to a number of recipes in the form of orange juice, lemon juice, or powdered citric acid. Some authorities also recommend the use of other acids such as tartaric, malic, or lactic acids.

It is often possible to taste the presence of acid in the must, but a more reliable method is to test it with the special indicator papers designed for the job and sold in small books or rolls. A leaf of the paper is torn out, dipped into the must and the colour that appears is matched against a colour chart. Acidity can be measured in terms of pH numbers 1 to 14, which actually represent the hydrogen ion concentration, but it is enough to know that low numbers, i.e. below 7, represent an acid solution whereas high numbers, indicate alkali. You should aim for a pH of 3 or 4. More elaborate methods of assessing acidity are available, but unnecessary for the beginner. A few fruits contain more acid than is normally required, and will impart an unpleasandy sharp taste to the finished wine unless this is corrected during fermentation. Raspberries and rhubarb are in this category, and it is wise to neutralize some of their acidity by adding precipitated chalk in small amounts. Again, you can use the pH papers to determine the correct level.

- Sugar: Many people believe that the more sugar added to the must, the more alcohol will be produced in the wine. This is only pardy true because yeast needs the correct amount of sugar to ensure its maximum efficiency. The optimum quantity of sugar is approximately 1.1 kg (2 1/2 lbs) of sugar every 4.5 litres (1 gallon) of liquid (250 grams per litre). This is the amount which will be used up by the yeast to ferment to its highest possible strength of about 15 per cent alcohol (by Volume). When this strength has been reached the yeast will be destroyed by the alcohol it has made, and fermentation will cease.

There are some wine yeasts, however, which have been specially developed to produce a strength of up to 18 per cent alcohol (by volume), but these need not concern the beginner.

If you use too much sugar, it is likely that the fermentation will become sluggish and finish too soon, leaving a large proportion of unfermented sugar in an understrength wine.

Usually, the most successful way of arriving at a wine of the right strength and sweetness is by adding sugar in the stages throughout the fermentation. Add perhaps half the total quantity specified in the recipe at the outset and the remainder in 100 g (4 oz), amounts as the fermentation slows. The hydrometer is a useful instrument to calculate the final percentage of alcohol.

Ordinary white granulated sugar is the most commonly used and best type to use, although you may like to try the same quantities of brown sugar to produce an attractive flavour in some heavier wines although it will also tend to impart a golden colour. You could certainly use caster sugar or icing sugar but they are more expensive and no better than granulated sugar.

Honey and golden syrup are also suitable for making some wines, but you should only use these as a small proportion of the total sugar content, to avoid "off" flavours. Honey will give about 75 per cent as much alcohol as sugar.

Invert sugar (you will need 50 per cent more) may also be used for winemaking. This is sugar which has been chemically split into its two components, glucose and fructose. As the yeast usually has to perform this reaction, invert sugar allows early fermentation to proceed more rapidly, but it is much more expensive and probably unnecessary.

- Tannin: Tannin is also required in certain recipes and, in small quantities, it will improve the taste of many wines. It occurs naturally in the skins and stems of fruit, but in wines made from other ingredients it can be added either in the form of strong tea solution, at the rate of 15 ml (1 tbsp) to every 4.5 litres (1 gallon) of must (approximately 1 millilitre per litre), or as wine tannin sold specifically for the purpose.

Small amounts of tannin will help to clear the must during fermentation and improve the keeping proprieties of the wine.

- The two stages of fermentation: Fermentation of the must, which is the fruit or vegetable extract, sugar, and water to which has been added citric acid, tannin pectin-destroying enzyme, yeast nutrient, and yeast is usually started in a polythene bucket or fermentation bin. The vessel must be well covered by a lid or sheet of plastic tied tightly to keep fruit flies at bay. This is the first stage, and is called aerobic fermentation because it takes place in contact with air. Aerobic fermentation is vigorous and lasts about four or five days, after which time it settles down. At this stage, the must can be transferred to a sterilized fermentation jar without the risk of the liquid bubbling over. It is advisable, however, to leave some room in the jar for any further activity of the fermenting must. The neck of the jar should be sealed with a fermentation lock to make the container air-tight.

This is the second stage, known as anaerobic fermentation, which takes place in the absence of air. After a few weeks of constant activity the mixture becomes progressively less active until, eventually, the yeast has produced all the alcohol it can, and fermentation ceases as the yeast is destroyed.

During this period, which can take four months or more, the must will change from a thick, cloudy ‘soup’ to a clear liquid with a separate deposit of dead yeast cells and unwanted solids, called the lees which form at the bottom of the jar. It is a gradual transformation at first, but an improvement in the colour and clarity of the liquid can be seen as the fermentation slows down.

- "Sticking" fermentations: Occasionally, a must will start fermenting normally but will cease working after a short period of time. This condition is known as a ‘sticking’ fermentation and can be caused by one of several factors.

As we have seen already, the correct temperature is most important in maintaining a steady fermentation.

Another cause of sticking fermentation is the lack of sufficient yeast nutrient or acid in the must. The addition of another 5 ml (1 tsp) of vitaminized yeast nutrient, or 5 ml (1 tsp) of citric acid will usually get the fermentation under way again.

If you have used an inferior yeast, it is possible that it has reached its alcohol tolerance limit and cannot go on working. To rectify this, prepare a starter bottle from a wine yeast that has been specially developed to go on working in higher concentrations of alcohol and introduce this to the must when it is fermenting vigorously.

You should also make sure that a fermentation which appears to have stuck has not actually used up all the sugar from the must and finished normally.


A lthough it is not absolutely essential to use a hydrometer to be able to produce good wine, it is a most useful aid, and will ensure consistent results.

The hydrometer is an instrument which measures the specific gravity (the mass of the liquid compared to that of water which has an S.G. of 1000) of a liquid. Itconsists of a long glass or plastic tube weighted at the bottom, and with a scale of figures marked down its length. The smallest figure is at the top and the largest figure at the bottom. The scale enables the winemaker to calculate how much natural sugar is present in the must, and how much will have to be added to achieve a wine of a predetermined alcoholic content.

As more sugar is added to a liquid, it becomes denser (its specific gravity increases), allowing objects to float in it more easily. If you continue to dissolve sugar in a liquid with a hydrometer floating in it, you will see that gradually the hydrometer floats higher and higher as the specific gravity of the liquid increases.

The first calculation to make with the hydrometer is to determine the amount of natural sugar that is present in the must This will give you the opportunity to adjust the S.G. of your must by either diluting it with water, or adding sugar, to give the potential alcohol content to suit you. This is important because some ingredients make a sweeter must than others, and the amount of sugar to be added for a correct fermentation to take place will have to be adjusted accordingly.

- Taking a reading: Pour some of the must into a hydrometer float jar or other suitably tall transparent vessel, until it is nearly full place the hydrometer in the liquid, heavy end downwards, and rotate it briskly to dislodge air bubbles that may be clinging to it. Usually, the hydrometer should be used in liquids at a temperature of 15.5°C (59.9°F) because most instruments are designed to work accurately at this temperature.

When the hydrometer is floating perfectly still, and not touching the sides of the jar, take a reading. Rotate the hydrometer brisky to remove air bubbles. Make sure that your eyes are at the surface level of the must when you look at it. The figure on the graduated scale that is level with the surface of the liquid, ignoring the meniscus, shows the specific gravity.

You should bear in mind these figures are not entirely accurate because the solids in the must at the beginning of fermentation and the alcohol at the end do obscure the results, but you can rely on the table as a good working guide.

The table also shows the percentage of alcohol by volume that is likely to be present in the finished wine for different amounts of sugar in the must. Compare the hydrometer reading taken from the must with the specific gravity column of the table. The figure that is closest to your reading will show you the potential alcohol content for that amount of sugar.

To increase the potential percentage of alcohol, simply add more sugar to the must, dissolving it a little at a time, until the hydrometer reading is reached that corresponds to the figure required for your chosen alcoholic strength.

As mentioned earlier, however, yeast will only make about 15 per cent of alcohol by volume. This means that it is poindess to add more sugar than the yeast will be able to use in fermentation, in the hope of achieving a higher alcoholic content.
All that will result is a wine that is too sweet to be palatable.

- Calculating the final strength: Alcohol has a lower specific gravity than water. During the fermentation, the specific gravity of the must will begin to drop, as sugar is converted into alcohol If the initial specific gravity is recorded, it is a simple procedure to work out the final strength of the wine.

When the wine has completely finished fermenting, take a hydrometer reading. (At this point you should record a reading of between 1-000 and 1-010.) Omitting the decimal point for this sum, subtract this figure from the initial reading. This will give you the overall drop during fermentation. Divide this number by 7,36 and you will arrive at the percentage of alcohol by volume in the wine.

- Example:
initial specific gravity - 1115
final specific gravity - 1003
overall drop - 112

112:7,36 = 15,2 per cent alcohol by volume

It is possible that you final hydrometer reading is less than 1000, in which case your wine will be very dry. But don’t forget that a really dry wine can always be sweetened to your own taste.


Before you prepare the must, make sure that all the utensils you intend to use are clean, and that you have sterilized them in a solution of 5 ml (1 tsp) of sodium metabisulphite in 600 ml (1 pint) of hot water. You can also add a few crystals of citric acid which help to release sulphur dioxide, the active agent. This should become routine whenever wine-making utensils are used.

Now is the time to extract as much flavour and colour from the ingredients as possible, and this can be done in several ways such as boiling, soaking in boiling water and soaking in cold water.

As the fruit contains wild yeasts and bacteria which may prove harmful to the must, it is necessary to destroy them by adding a Campden tablet to the mixture.

- Juice Extraction: Sometimes the best method of obtaining the most goodness from certain fruits is to use a hand-operated wine press. The obvious candidates for this method are grapes, apples, pears, and the other fruits and berries which contain a lot of juice.

First, cut up or mash the fruit and place it in the press, a little at the time. Collect the juice extracted from the fruit in a fermentation jar via a funnel to avoid spilling any.

A modern electric juice extractor, which separates juice from pulp, is an easier way of obtaining fruit juice quickly and efficiendy.

Juice extracted by either method can be fermented as it is, straight from the press, or it can be diluted with water to make it more economical and to avoid too strong a flavour. For example, 1.2 litres (2 pints) of pure apple juice together with 450 g (1 lb) of sugar, and 450g (1 lb) of sultanas can be made up with water, pectin-destroying enzyme, yeast and vitaminized yeast nutrient to make 4.5 litres (1 gallon) of white table wine. You can start the fermentation immediately and you may also add the pulp to the juice if you want a wine with more body.

- Adding the yeast: Whichever way you prepare the must, the procedure for adding yeast to the liquid is the same.

The first thing to do is to test the must for acidity with the indicator paper and add enough citric acid or lemon juice to bring the acidity to pH 3 or 4. If the must is too acid, add precipitated chalk. When the acidity is correctly adjusted, take a hydrometer reading and add the necessary amount of sugar (in stages) to arrive at a reading of approximately 1-100 for a dry wine or 1-120 for a sweet wine later.

Make sure that the temperature of the must is between 19°C and 24°C (66 to 75°F) before adding your yeast starter. Don’t forget the vitaminized yeast nutrient. Then cover the fermentation bin securely.

Fermentation will begin, quite violendy at first, and you should allow it to continue in the fermentation bin for about four or five days. Now transfer the must to a sterilized fermentation jar, leaving enough room for any other vigorous bubbling to take place without overflowing. Fit a fermentation lock partially filled with sulphite solution. Place the jar in a warm place and then you can watch the progress of the fermentation as carbon dioxide gas escapes in bubbles through the lock.


During the first few weeks, or months, of fermentation the must will be a thick, opaque liquid, with a suspension of particles of yeast and pulp, creating an overall haze.

As yeast is used up in producing alcohol, the dead cells fall to the bottom of the fermentation jar together with the unwanted particles of fruit or vegetable pulp. The thick deposits or lees must be separated from the clear wine to avoid any unpleasant taste that may develop if it is left in the wine for too long. Therefore, you will need to siphon off or rack the clear wine from the lees using the length of clear plastic tubing or specially designed siphon.

- Racking: Stand the fermentation jar of wine to be racked on a table, and place another clean, sterilized jar on the floor beneath it. Remove the fermentation lock and bung, and put one end of a length of plastic tubing carefully into the jar, to reach about half way down the liquid. Hold this in position and gendy suck the other end of the tubing.

As the wine fills the tubing, tightly pinch the end you are sucking, and place it inside the neck of the empty fermentation jar. Release finger pressure and the wine will flow smoothly into the new container.

You must ensure that the level of the wine in the jar being siphoned does not fall below the end of the tubing. Gendy push the tubing further into the wine until it is impossible to draw off any more liquid without disturbing the lees.

When all the clear wine is safely inside the new fermentation jar, add a crushed Campden tablet to avoid any bacterial contamination. Top up the jar to its shoulder with a solution of sugar and water (in the same proportions as the original wine) to compensate for the amount of lees that has been discarded. Fit a clean fermentation lock. Racking at intervals of about one month is advisable and will ensure that the wine dears rapidly.

- Fining: A wine will usually clear naturally given enough time and regular racking particularly if it is placed in a cool place when fermentation has finished.

Occasionally, however, a wine will remain persistendy cloudy and you will have to try to clear it artificially. Chemical substances, known as (fining), are available in a number of proprietary brands, and contain such ingredients as isinglass, gelatine, casein, and egg whites.

Following the manufacture’s instructions, add a small amount of finings to the wine. After a short time the wine should clear and a solid deposit will be left at the bottom of the fermentation jar. You can then rack the wine in the normal way.
Probably the best fining agent to use is bentonite. It is a powdered clay mineral originally formed by the alteration of volcanic rocks. To use bentonite, put some of the powder into a sterilized screw-top bottle and add a small amount of the wine to be fined. Screw on the top and shake the bottle vigorously. Leave the mixture for twenty-four hours and then add it to the wine, which will clear rapidly after the treatment.

- Pectin Haze: If the wine has been made by boiling fruit or certain vegetables that contain a lot of pectin, it is possible that a haze may develop. Wines that are likely to be troublesome are best treated at the initial stages when the must is being prepared, but the fault can be rectified later by adding one of the pectin-destroying enzymes which are widely available.

Pectin is a gelatinous substance present in fruit and vegetables in varying qualities. It is of great benefit in making jam because it causes the jam to set, but it is most undesirable in winemaking because it forms a jelly-like haze, which remains in the suspension after fermentation.

To avoid a pectin haze forming, or to remove one that has formed, you should treat the wine with a pectin-destroying enzyme. This enzyme is called pectinase, and it is available as either powder or liquid, under various brand names. Follow the manufacturer’s instructions to decide how much pectinase to add to your must
Many winemakers add pectin-destroying enzyme to all fruit and vegetable wines when the mashed pulp is cool, and before the sugar has been added. Although pectin is present in all fruit and vegetables, some have it in larger amounts and are more likely to throw a haze. The worst offenders are apricots, damsons, parsnips, peaches, plums, and potatoes.

It is easy to decide whether or not a haze is caused by pectin. Add a small amount of the wine to be tested to methylated spirits in a bottle and shake it vigorously. Leave the mixture to settle for some time. If jelly-like strings or "blobs" have formed, the haze is the result of pectin being present in the wine.

- Starch Haze: Unripe apples and a few root vegetables, notably parsnips and potatoes, are liable to produce a starch haze in the fermented wine if they are boiled too violently. If this haze does not clear when the wine has been kept in a cold position for some time, you should use a starch-destroying enzyme, called amylase and which, like pectinase comes in powder form and should be added to the must according to the manufacture’s instructions.

- Filtering: Filtering will not remove pectin or starch hazes, but it can be considered as a last resort for an obstinately cloudy wine.

A filter paper, folded to fit into a funnel may be used although modern filter kits are better because they are air-tight and avoid the possibility of the wine becoming oxidised.

Wine is passed through the filtering system, and the filter paper, or pad, removes even the most minute particles of unwanted material. The filtering medium should be changed regularly to prevent it becoming blocked.


Sometimes, despite all your care, wine doesn’t turn out as expected. It may even stop fermenting prematurely. Use this checklist to identify and solve the problem.

- Your wine smells and tastes of vinegar: There are probably only two things you can do throw it away or wait until it turns completely into wine vinegar. The wine has been infected with the dreaded vinegar fly. You were probably not careful enough about sterilizing your intensils, or you may have left the wine exposed to the air for too long. Perhaps the water in the fermentation lock evaporated or you forgot to add any sterilizing solution to it. Be careful, though, that you have not mistaken vinegar for dryness-it would be a pity to throw away perfecdy good, but very dry wine which can easily be sweetened by the addition of a little sugar, or blended with another sweeter wine.

- Your wine develops a haze which fining and filtering fail to clear: The haze is probably caused by starch the wine has been made from root vegetables, or by pectin if you have made a fruit wine. You have forgotten to use a starch or pectin-destroying enzyme or you have not used it in sufficient quantity. Keep the wine for your own use rather than serving it to friends: it should taste perfecdy all right, but it will have a less attractive appearance than bright wine.

- You have made a red wine, but it has become brown and cloudy: Sadly, you have allowed the light to get at it during fermentation or after it was bottled and it is probably undrinkable. If you make sure that the acidity of the wine is correct, this will help to avoid browning but you should keep red wine out of the light at all times and it should be stored in dark bottles and kept in a dark place.

- Your wine develops whitish specks on the surface which eventually becomes oily: This is known as flowers of wine and is caused by a particular strain of wild yeast which converts the wine into carbon dioxide and wine will eventually become watery and lifeless. If you notice the effect when only a few specks of the yeast have developed you can treat it by adding two Campden tablets per 4.51 (1 gallon) of wine. Otherwise you should throw the wine away and be careful to sterilize all your utensils before using them again.

- Your wine stops fermenting while still sweet, and the S.G. is much higher than 1.000: This is called a stuck fermentation and can be caused in a number of ways. It can usually be put right provided you make sure there are no other ailments such as off odours.

You may have made your must too sweet so that the yeast is killed by die high concentration of sugar (check the recipe), or it may have reached its alcohol tolerance. You may be keeping the fermentation vessel in a placewhere the temperature is either too low or too high for the yeast to survive. The acidity may be incorrect. You may have used too many Campden tablets and these may have killed the yeast.

If the fermentation is stuck for any of these reasons, then you have not followed carefully enough the guidelines outlined in this book. But all is not lost. Give the wine a vigorous stirring with a clean wooden or polypropylene spoon. Check the acidity and temperature and note the S.G. Add some vitaminized yeast nutrient and this should get things going again. If after a few days, the wine is not bubbling vigorously again, make up a new starter bottle and add to the wine.

- Your wine smells and tastes strongly of sulphur dioxide: You have added too many Campden tablets. Eventually, it should disperse, but a vigorous stir will help.

1 comentario:

  1. Thank you for this excellent synopsis of wine making. As a relatively new starter I have learned much from you that no other winemaker that I have read if watched on the internet has even hinted at. You have helped me save one batch of Rasberry Mead and one batch of elderflower and Apple. Sadly I never read your article in time to save my previous attempts at elderflower and Apple wine. As my father was often fond of telling me; " we learn more from our mistakes than from when things go right."
    I found you after searching in earnest for a solution to what I thought was a stuck fermentation problem, however, after reading your article I discovered that I had used insufficient sugar and that my wine and mead both needed a top up and the overly dry taste was offset considerably (my gravity reading was 995!) And my alcohol % was only at 9.2%. Fortunately all I had to do was add a sugar solution and a teaspoon more of nutrient. The flavour has much improved and the brew has once more started off again. I think I will benefit with a much more balanced product after a couple of months of racking. Once again, I thank you for taking a great deal of the guess work out of my winemaking. When I eventually open my first bottle I will raise my first glass to you and your good health. Gerry Thompson