Winemaking - FAQ (part 2 of 2)

In case you've not read our original winemaking FAQ page... click here.

1. How quickly can wine be made?
2. What equipment do I need?
3. What is the easiest wine to make at home?
4. I know yeast is important, but what does it actually do?
5. Does all wine improve with age?
6. What's special about grapes?
7. What other fruits can I use?
8. Can I use bruised or slightly rotten fruit?
9. Can vegetable juices be used?
10. Must I use yeast?
11. Why and when should I use yeast nutrient?
12. Can I use bakers yeast?
13. What amount of yeast should I add?
14. Do I have to add chemicals to my wine?
15. Why should I need wine finings?
16. What are sulphites used for?
17. What is pectolase used for?
18. Is sulphite the only preservative used?
19. What type of fermentation heater are there?

How quickly can wine be made?

The quickest way to make wine is to buy grape juice, a general purpose wine yeast and granulated sugar. This will can be done in a month, depending on temperature but beware any that state it can be done in less time

What equipment do I need?

To get started, the only equipment you need is a plastic pouring funnel and a five litre (one gallon) drinking water container. But you do need a good reliable method. If you take up the hobby seriously, you will want a glass thermometer and a hydrometer (see below). You might want an electric heating mat to keep your fermentation warm, but it is really better just to make your wine in a warm place. When you start designing your own recipes, you should buy an acid testing kit.

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What is the easiest wine to make at home?

Still dry table wine. At around 11-12% alcohol it is well within the tolerance of a good wine yeast. Dry wines are easier because, when all the sugar is used up, the fermentation stops by itself. Sweet wines have to be stopped artificially. Strong dessert wines need special techniques to ferment beyond about 14%. Sparkling wines need particular care and attention. But this is all good news - the easiest wine to make is also the most popular type!

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I know yeast is important, but what does it actually do?

It does two things. At first, it multiplies by replication, vastly increasing its numbers, and in the process it uses up all the oxygen in the juice. Then it starts to release enzymes which break down the sugars to form alcohol and carbon dioxide gas. That is why fermenting juices froth and bubble.

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Does all wine improve with age?

Generally yes, if stored correctly (cool, dark and airitght and not for too long. All wine will improve with a little ageing, but long ageing will only help a wine that has been specifically designed to be aged, and such a wine will often be pretty unpalatable until it has been aged. Red wines generally need a longer rest than whites, because of higher tannin levels.

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What's special about grapes?

They can contain the best balance of sugars, acids and tannins needed for a quality wine. Also, wine yeast is a cultivated form of grape yeast, so grapes are its natural environment.

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What other fruits can I use?

You can make wine from most fruits, but you will usually need to add some sugar and possibly some acid (lemon juice will do). As no single fruit has the same balance as grapes, it is often a good plan to use pairs of contrasting types. E.g. Grapefruit is too acid and not sweet. Bananas are sweet but with no acid. Get the idea?

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Can I use bruised or slightly rotten fruit?

Better not to, it can be risky. The organisms that cause the rotting will compete with your yeast for colonisation. If the yeast wins, you might be ok, but if it loses, you'll end up with a pretty grim brew. Use fresh, ripe, sound fruit if at all possible. If you wouldn't bake it in a pie, don't put it in your wine!

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Can vegetable juices be used?

Yes, but not on their own. you will need to add sugar and acid because vegetables are very low in both. Or you can mix vegetable and fruit juices. Be a little careful with vegetable-based wines as they can sometimes contain undesirable alcohols as well as the ethanol. Even traces of methanol are dangerous to health.

To prepare them if you have a juice extractor, use it! Otherwise, chop the vegetables fairly small, boil them in water (don't add salt!) but don't let them disintegrate. Strain off the liquid and leave to cool. Eat the vegetables (waste not, want not!) Remember to add sugar and acid to the vegetable juice, or blend with fruit juice. (Or both).

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Must I use yeast?

Yes! A sweet fruit juice might start fermenting all by itself, but that's only because some airborne wild yeast has contaminated it. Some wild yeasts are capable of producing wine, but most are not. It is far better and safer to use your choice of wine yeast and be in control of the process.

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Why and when should I use yeast nutrient?

Yeast nutrient is the winemaking equivalent of garden fertiliser. Yeast is a single cell 'plant' that, just like garden vegetables, needs the right nutrition. In particular, it needs a source of fermentable nitrogen. If this is lacking, the fermentation may stop completely, or it may take a wrong turning and start producing hydrogen sulphide, the bad egg gas. You can obtain yeast nutrient from any winemaking supplier. For quantity, follow the manufacturer's instructions, and always add it to the juice before starting the fermentation.

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Can I use bakers yeast?

It's better than trusting to luck with wild yeasts, but it's still not a good idea. Baking yeast will certainly start your fermentation, but it has a low alcohol tolerance, and will die before completing the job. This will leave you with a wine that is too sweet. It's much better to use a good quality wine yeast.

What amount of yeast should I add?

You don't need much simply because it multipies by itself! But don't just add it straight to the juice. Add about a teaspoonful of dried general purpose wine yeast to about half a pint of the juice. Shake it, cover it, and leave it in a warm place for about 24 hours. When it has come alive, you can add the rest of the juice.

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Do I have to add chemicals to my wine?

Not always! You can make dry table wine from fruit juice, sugar and yeast. Nothing else. It feels good not to use chemicals topo. But there are two main reasons why winemakers use additives. 1) Not all juices contain enough natural nutrients to keep the yeast alive and healthy throughout the process. 2) Wine that is to be matured can benefit from added antioxidants to delay the natural oxidation process until ageing is well advanced.

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Why should I need wine finings?

Finings simply help a wine to clear. Most wines will fall clear by themselves, especially if you refrigerate them for a few days. But some may form a haze which refuses to settle out. Finings added to the wine can help the tiny haze particles to coagulate and fall as sediment, or in some cases to adhere to the finings particles and settle out together. There are problems though. Different types of haze may require different finings, and the wrong addition can simply add to the haze.

In fact there are two broad types of finings: organic, and inorganic or mineral. Organic finings (e.g. egg white, casein) react chemically with the haze and therefore have to be selected and measured with knowledge and care. Mineral finings are little more than insoluble fine heavy particles that slowly fall through the wine collecting the haze in passing. They are much easier to use.

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What are sulphites used for?

Sulphites are added to wine as sodium metabisulphite or potassium metabisulphite. Both chemicals act as a source of free sulphite ions in the juice. The sulphite does two useful things. 1) It prevents contamination of the juice by wild yeasts and other spoilage organisms. 2) It acts as an antioxidant, by sacrificially oxidising itself, forming sulphates in the process. Without sulphites, white wines tend to go brown and flat, like a sliced apple.

If you are making table wine from purchased juices, for early drinking, then you do not need to use sulphites. But if you are using fruit or vegetables, or if you intend maturing the wine, careful use of sulphites is recommended.

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What's pectolase used for?

Pectolase, or pectolytic enzyme, breaks down pectin in a wine must. Pectin makes jams and jellies set, but is not helpful im wine as it can form a haze that will not settle. Juice wines usually don't need pectolase, but pulp-fermented wines may extract too much pectin from the fruit, causing trouble later. Pectolase added to the pulp has two effects - it reduces the risk of pectin hazes and also increases the juice yield from the pulp, as the pectolase breaks down the cell walls and helps liquify the pulp.

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Is sulphite the only preservative used?

No. Some winemakers add potassium sorbate at the end of fermentation. This forms sorbic acid in the wine, which is a yeast inhibitor. You don't need it in dry wines, but it can be used to prevent intended semi-sweet or sweet wines from continuing to ferment past the desired end point. Note that sorbate is genuinely a preservative, whereas sulphite is technically a retardant but still an active part of the winemaking and maturing process.

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What type of fermentation heater are there?

The two commonest types are electric mats and electric belts. The mat is easier to use. It is like a small electric blanket that you slip underneath the fermentation vessel. They can be quite useful, especially in the early stages when you want to help the process along, but later, when a sediment starts to form, applying heat directly below the sediment can release off flavours into the wine. The fermentation belt solves this problem, as it is wrapped round the outside of the vessel just above the sedimentation level. So, the belt is a better choice than the mat, but better still is simply to control the ambient temperature and use no heaters at all.