One golden rule of home winemaking is that the best quality fruit produces the best quality wine. Select your ingredients carefully, choosing sound ripe fruit wherever possible. Wash it before use, and cut out any soft or brown patches. Certain fruits, such as gooseberries, blackcurrants and pineapples, need "topping and tailing" before use. The stones may be left in smaller fruits - it would be an impossible job to take them out - but are best removed from plums and peaches.
If any stones are cracked, the kernels will impart a pronounced and irremovable almond flavor to the wine, so do not use electric pulpers or juicing machines on this kind of fruit! The pips of citrus fruits and grapes do not affect a wine if they are not crushed. You must, however, be very careful to exclude citrus fruit pith, for this imparts a very bitter taste to a wine. The same is true of the flesh of the grapefruit.
Sometimes fruit looks ripe when it is still quite acidic. Consider damsons, for example. Very often the damsons bought at greengrocers' shops are under-ripe and acidic, even though they look black. Such fruit will make a better wine if it is left to ripen in a dry, clean place. If you do use fruit when it is hard and slightly sour, it is a good idea to boil it for a few minutes to soften the tissue and lessen the acidity. You can then pulp ferment in the normal way. The only exception to this rule is that unripe gooseberries are far preferable to soft, ripe ones. This is because the strong flavor of the ripe fruit is too pronounced in a finished wine.
One final word about fresh fruit. Berries are best gathered on a dry day, if possible. This is because they absorb water when they are wet. Thus on a wet day one has proportionately more water and less flavor for a given weight of fruit than on a dry day. This problem can be avoided by adding extra fruit if It has been gathered on a wet day.
Canned and bottled fruit is of course sterile and soft, so it can be poured directly into a fermentation bin and pulp fermented without any preparation. Similar reasoning applies to commercially produced fruit juices, concentrates and syrups. However, if you have prepared a juice yourself by pressing fresh fruit, it is a wise precaution to dissolve two Campden tablets in each gallon (4.5 litres) of juice or must and leave it for twenty-four hours before adding any yeast.
Dried fruit needs careful preparation. Although the high sugar content prevents decay during storage, there will still be many bacteria that can spoil your wine on the fruit. Before you use it in winemaking, it needs to be washed in cold, running water and then boiled (some recipes call for this) or soaked in sulphited water for twenty-four hours. It can then be treated like fresh fruit. Some dried fruits, in particular sultanas and raisins, are sometimes lightly coated with oil before they are packed, to prevent them sticking together during storage. This oil must be removed by washing the fruit in hot water, otherwise it will float on the surface of the must and wine.
The same guidelines apply to vegetables as apply to fresh fruit. Use good quality ingredients. Scrub the vegetables well (but do not peel), remove any bad parts and chop before boiling. Only the liquid is used in making wine; the chunks are discarded.
Flowers, like berries, are best gathered on a dry day. Individual blossoms like elderflowers can be combed off the stalks using a comb with widely spaced teeth. Other flowers such as dandelion and coltsfoot need to be picked off the green stems and the outer green part of the flowers as much as possible. More detailed instructions are included in the relevant recipes. Dried flowers are certainly more convenient, in that one is spared the chore of picking them; however, lie careful to remove all foreign matter such as stones or sticks from the petals, and rinse them in sulphited water and drain before you use them. Never use boiling water on flowers, especially dried ones.
Cereals can be obtained as either whole grain or flakes. I recommend the use of whole grain, which is cleaner and easier to use. Since all the flavor of the cereal grain is concentrated in the outer husk or epidermis, it is not necessary to mince the grain as is sometimes suggested. Wash the grain well to remove dust, then pour on hot water to extract the flavor. Full details can be found in the relevant recipes.
STRAINING THE MUST
The success of winemaking depends to a large extent on the care with which the liquid is strained from the fruit pulp or other ingredients. The aim is to allow as little solid matter as possible into the demijohn for the anaerobic fermentation. Thus one should avoid squeezing pulp through a straining mesh or bag, since this will puree the material and allow it to pass through into the wine. In fact only the gentlest pressure should be exerted on the solid material. It is far better to roll the pulp around a straining mesh and wash it with water than to squeeze it in an attempt to extract every last remnant of flavor.
Coarse, medium and fine nylon mesh sheets ideal for straining solids from liquids can be obtained from winemaking stores.
Do not confuse straining with filtering. To strain a wine must is to remove the coarser particles or chunks of solid matter from the liquid; yeast and other such tiny particles pass easily through a straining bag. To filter a wine is to pass it through a very fine sieve with microscopic holes, the idea being to remove all suspended matter and leave a brilliantly clear liquid.
OTHER WINEMAKING INGREDIENTS
Ordinary tap water is best for winemaking. If the supply is known to be treated, one could even take a chance and use it straight from the tap. However, it is wisest to boil all water before use; this will drive off any chlorine and ensure that it really is sterile. (Incidentally, this problem of excess chlorine in the water supply seems to have become much worse in recent years. In some areas of Britain, the level of chlorine is apparently so high that it spoils both the color and taste of the wine unless the water is treated first! For small batches of wine, it is a simple enough matter to boil the water before use; however, for 5 or 10 gallon fermentations (25 or 50 litres) you will find it more convenient to buy a small water purifier. These are filter devices which clip on to the tap and remove the chlorine by chemical action. They are not hard to find, and can be useful if you have this problem.
Rain water and well water are not recommended for winemaking. There is no good reason to use them, anyway, since the hardness or softness of water has no effect whatsoever on winemaking. Distilled water will not work at all since it lacks the essential "trace" elements necessary for the growth of a yeast colony.
Fruit and vegetable matter contains a gummy carbohydrate substance called pectin between the cell walls. This pectin is, in effect, the cement which holds the cells of the fruit together (this glue-like property makes pectin suitable for use in jam-making - it ensures a firm set). However, pectin released by the preparation of fruit or vegetables for winemaking can cause a cloudiness in the finished wine. Fortunately this problem can be overcome by the use of a commercially prepared pectin destroying enzyme which is added to the cool must at the beginning of fermentation. Another advantage is that the use of a pectin-destroying enzyme also seems to improve the flavor.
Preparations of pectic enzyme will remove any pectin released into the must during preparation; they are available under different brand names, such as Pectolase, Pectinol, Pectolytic enzyme, Pectic enzyme and so on. In addition there is a specialized preparation known as Rohament P, which releases the color and flavor of chopped fruit. This is especially useful when one is making wine from hard fruits like apples without a fruit press.
However, Rohament P will not, on its own, produce a pectin-free must, so it should be used in conjunction with one of the pectic enzymes mentioned above. If a recipe specifies "pectic enzyme" and it is added in accordance with the instructions on the packet, the finished wine should be clear and bright. If you do happen to produce a wine with a haze, you can easily test for pectin as described later. If the test proves positive, a double dose of enzyme can be added to the finished wine. However, pectic enzyme is best added to a must and not to a finished wine, in which its action is less effective.
DIASTASE OR FUNGAL AMYLASE
Some ingredients - notably cereals and root vegetables - contain starch, which can produce a haze in the finished wine. The addition of the starch-destroying enzyme diastase (sometimes known as fungal amylase) will prevent this. The recipes clearly indicate when it is required; use it as directed on the packet. (Enzymes are chemical compounds produced by living cells. They are responsible for the conversion of one substance to another, e.g. sugar to alcohol during fermentation. However, an extract of enzyme can work independently in a wine must.) The acidity of a wine must plays a major part in determining the quality of a finished wine.
A serious lack of acid makes a wine taste distinctly "medicinal" (a flavor which cannot be removed); a slight lack of acid makes a wine taste dull, flat or insipid; too much acid makes a wine sharp and sour to taste. Acid is also important in the development of good bouquet in a wine. During fermentation and storage, the acids react with the alcohol to produce a set of volatile chemical compounds known as esters. It is these compounds which are chiefly responsible for the good bouquet of a wine; without enough acid in the must, they do not develop.
But besides the obvious advantages mentioned above, the correct level of acidity is Important in other ways. Yeast needs an acidic environment for effective fermentation; and the correct level of acid in a wine helps to inhibit the activity of spoilage bacteria - and so acts as a natural preservative during fermentation and storage. There are three main acids used by the home winemaker: citric, tartaric and malic. Citric acid is the acid of citrus fruits. It always has been, and still is, the most useful acid for home winemakers. This is because its taste is quite acceptable and it effectively provides an acidic environment for the yeast. Old recipes specify lemons or oranges as a source of citric acid; newer ones indicate the required quantity of citric acid crystals. Using the crystallized form of the acid is simple, convenient and easy because the crystals dissolve readily in water.
Tartaric acid is the main acid found in grapes and, of course, grape juice concentrates. It is available to the home winemaker as tartaric acid crystals. Its great advantage is that any excess acid will precipitate out as insoluble potassium tartrate during the later stages of maturation. Some red fruit recipes seem to be improved by the use of tartaric rather than citric acid. You can use a 50/50 blend of tartaric/citric acid so as to obtain the advantages of both types of acid. This mixture substitutes for an equal quantity of either citric or tartaric acid.
Note that potassium tartrate also tends to precipitate out if a wine is cooled. This is not a problem with red wines, which are served at room temperature; however, tartrate hazes can develop in a white wine which is chilled before serving, and so tartaric acid is best avoided in white table-wine recipes. (If a red wine should happen to throw some crystals, for example during storage in a cool place, you can easily decant it off the crystals before you serve it.)
Malic acid is another acid naturally present in the grape, and also in apples. Too much malic acid can impart a sharp and sour taste which is not entirely acceptable In a good quality wine. Fortunately this problem only occurs with very acidic apples, and it can be dealt with artificially by adding potassium carbonate or naturally by a malo-lactic fermentation. A malo-lactic fermentation is quite a rare event. It is not caused by yeast, but by the lactic acid bacteria which can convert malic acid to lactic acid. When it happens, a winemaker may be puzzled to find that his wine appears to be fermenting very slowly for a long time after the yeast has used up all the available sugar. In such a case, the normal yeast fermentation has indeed ended, but has been superseded by a fermentation of malic to lactic acid with associated production of carbon dioxide.
Apart from the fact that it is annoying to have a finished wine fermenting during storage, a malo-lactic fermentation is generally regarded as a good thing, because lactic acid has a pleasant taste and contributes to a good bouquet. Lactic acid can be purchased as a solution in water. One teaspoonful added to each gallon (4.5 litres) of wine must produces a significant improvement in a wine's bouquet after storage. One teaspoon of 50 per cent lactic acid solution replaces half a teaspoon of citric or tartaric acid crystals.
CHECKING THE ACIDITY
Although you can obtain satisfactory results by following a recipe, obviously one problem is that fruits do vary in acidity from year to year. You may therefore wish to check the acidity of your wine must and adjust the quantity of acid used in the recipe accordingly. Clearly you need to carry out such a test when you've compounded the full volume of the must, because dilution of the must will also dilute the acid.
The simplest way of checking acidity is to use pH indicator paper (pH is a measure of acidity: pH 7 is neutral, less than pH 7 is Acidic, and over pH 7 is alkaline.) The indicator paper is simply dipped into the wine must. It then changes color and can be compared to a standard color chart which shows the corresponding acidity. An alternative method is to use titration or a wine acidity test kit.
Full instructions are supplied with this equipment, but the principle is very simple: the acid in a small measured volume of must reacts with standard sodium hydroxide solution containing an indicator which changes color at a certain pH. The volume of sodium hydroxide solution required to bring this change about can be converted to an acidity reading for the must. In general, wine musts should have an acidity of between pH 3 and 4. pH 3.3 is the figure usually quoted for a table wine.
However, a wine which is finished sweet and strong needs slightly more acid, say pH 3.1. These figures are equivalent to an acidity level of about 5 parts per thousand (ppt) for a table wine must and 7 ppt for a strong, sweet wine must. If you think your must is too acid (as it may be with certain fruits, notably blackcurrants and citrus fruit) it is wiser to wait until the wine is finished before making any adjustments.
Remember that you can always remove acidity, but a wine whose flavor is spoilt because the must contained too little acid will be irretrievable. If you do need to reduce a wine's acidity, you can use "wine acid reduction solution," available from winemaking shops, or you can use potassium carbonate solution. This is explained more fully in the section "Faults and remedies."
Another method of adjusting the acidity of a must which one sometimes sees recommended is the addition of precipitated chalk (calcium carbonate). I have tried this myself and found it to be unsatisfactory for several reasons. First of all, chalk is not soluble, which means that the must has to be stirred until the excess acid is sufficiently neutralized. Next, the must has to be left undisturbed until the chalk has settled out - sometimes one even has to filter it. Lastly, the must needs re-acidifying with citric acid or lemon juice. All this is tedious enough, but much worse is the fact that the color and flavor of a wine can be spoiled by the chalk.
If, despite these problems, you wish to try the technique, 0.5 to 1 ounce (15 - 30 grams) of chalk should be enough for even the most acidic must. However, my advice is to avoid this procedure if at all possible. Another technique for adjusting the acidity of a must or a finished wine which can cause more problems than it cures is adding water to dilute the acid. In the case of a must, you will also dilute the flavor, and in a finished wine you will dilute both flavor and alcohol content.
Finally, remember that most wines, no matter how acidic or astringent, will mellow with keeping.
Tannin is a compound derived from the skin and pips of fruit. It helps to balance the flavor of all wines and provides a sharpness or "bite" without which a wine is dull and insipid. Red berries and fruits such as grapes, elderberries and bilberries contain a great deal of tannin; obviously flower, vegetable, cereal and white fruit or juice wines will contain little or no tannin. To make up this deficiency, powdered grape tannin may be added to a must. The powder clots if added straight to a must, so it needs to be creamed into a smooth paste with a little water before being well mixed into the bulk. The quantity required is indicated in each of the recipes; in general, this varies from one-eighth to half a teaspoonful. Older recipes indicate the use of strong tea, which is a rich source of tannin. The quantities vary from a tablespoonful to a cupful - which is one reason why modern recipes, with a specifically defined quantity of a uniform substance such as grape tannin, are a considerable improvement. Wine with tannin will keep much better than wine without. In general, the more tannin a wine contains, the longer it will need in storage before the flavor has mellowed enough to be pleasant. This is one reason why rich red grape wines (and some home-made wines) made with large quantities of fruit may need to be stored for years before use. During this storage and maturation, the subtle chemical changes which take place in the developing wine include the precipitation of excess tannin.
The optimum storage time for a home-made red wine, using an average amount of fruit, will probably be about six months. This does not, of course, mean that the wine cannot be drunk this! However, some red fruits - for example, elderberries - contain a great deal of tannin and may require even longer storage. Fortunately the storage times can be kept to a minimum by avoiding a lengthy pulp fermentation (which (extracts the tannin from the skin of the fruit) and using the minimum quantity of fruit. Other useful techniques which avoid the extraction of too much tannin include hot water extraction, carbonic maceration, and, in the case of elderberries, the use of juice pressed from the fresh berries rather than the whole fruit.
I shall return to the subject of tannin in later sections; for the moment, three points only. First, if a wine is found to contain too little tannin, more can be added later at any stage. Secondly, it's useful for each individual winemaker to learn how much suits his palate and to adjust the recipes accordingly. Thirdly, you don't really want tannin in white wine recipes - or at least, not much. Follow the recipes and you should be OK.
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