Wine FAQ

Welcome to the Winemaker's FAQ where you'll find answers to all your wine-making questions! I've grouped similar questions together to make it easy to find what you're looking for.


What is the quickest way to make wine?
The quickest way is to let other people do the hard work for you! Buy supermarket grape juice, general purpose wine yeast and granulated sugar, and follow the step by step instructions in my beginner's post, Paraglider's simple wine. This will take 3 to 5 weeks, depending on temperature. Beware of Internet recipes for one-week or two-week wine. I've never seen one that wasn't seriously flawed. I've seen some that were positively dangerous!

What is the easiest wine to make?
Still dry table wine. Table wine is around 12.5% alcohol, 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!

Is it legal to make my own wine?
In most Western countries, it is legal to make your own wine and beer, but not to distil the spirit from it. It is generally prohibited to sell it without a special license. In Islamic countries, whether or not there is a law specifically prohibiting home wine-making, it is safe to assume that were you to ask permission, it would be refused. Therefore, proceed with discretion in the privacy of your apartment and don't discuss it openly. It is no part of my mission to land my readers in jail!

Does wine really improve with age?
Yes. The older I get, the more I like it! Seriously though, 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 their higher tannin content.

Which is stronger, homemade or bought wine?
There is no difference if the home wine recipe is well designed and executed. So-called yeast-free or sugar-free recipes turn out quite a lot weaker than commercial wines. The folk tales of Grandpa's parsnip wine that was as strong as whisky have two explanations: 1) the stuff tasted foul and gave you a raging headache because it was poisonous, not strong; 2) the old man was secretly distilling it in the potting shed. Naughty Grandpa!


What's special about grapes?
Wine grapes, properly grown and ripened, can contain the ideal 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. And a happy yeast makes a better wine.

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?

Can I use bruised or slightly rotten fruit?
If you must, but it's 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. It's always best to use fresh, ripe, sound fruit. If you wouldn't bake it in a pie, don't put it in your wine!

Can I use vegetable juices?
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.

How do I prepare the vegetables?
If you have a juice extractor, use that! If not, 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).


Can I make wine without using yeast?
No. 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.

Can I use baking yeast (bread 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 may 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 exactly does the yeast 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.

How much yeast should I add?
You don't need much, because it grows by itself. But don't just add it straight to the juice. Add about half a teaspoonful of dried All-Purpose Wine Yeast to about 250 ml 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.

Where can I buy wine yeast?
If you don't have a wine-making supplier near you, there are plenty that do mail order. Google for wine-making supplies. And choose 'all purpose' or 'general purpose' wine yeast.


Why do I need to add anything to my wine?
In many cases, you don't. You can make dry table wine from fruit juice, sugar, yeast, and nothing else. And it's satisfying to do so. 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.

What is yeast nutrient? When do I use it?
Yeast nutrient is the wine-making 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 wine-making supplier. For quantity, follow the manufacturer's instructions, and always add it to the juice before starting the fermentation.

What is DAP?
DAP is diammonium phosphate. It is the principal active ingredient of yeast nutrient. Only specialists and professional winemakers would have reasons to use DAP on its own. Just stick to general purpose yeast nutrient.

What is pectolase used for?
Pectolase, or pectolytic enzyme, breaks down pectin in a wine must. Pectin makes jams and jellies set, but is not helpful in 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 liquefy the pulp.

What are sulphites? Do I need to use them?
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 supermarket 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.

What are Campden tablets?
Campden tablets are aspirin-sized pills of potassium metabisulphite. They offer the most convenient way of adding a controlled quantity of sulphite to a wine. But they are not very soluble and should always be crushed (between two spoons) and dissolved in a little water before adding to the wine. Keep Campden tablets out of the reach of children.

Doesn't sulphite smell bad?
Sulphur dioxide is a poisonous gas with a sharp, pungent smell. If you sulphite a wine at the end of fermentation, to stabilise it and prevent early oxidation, then you should not be in a hurry to drink it. As the wine matures, the sulphite level drops steadily. When the wine is ready for drinking, there should be no discernable sulphur dioxide smell. Sometimes you can smell sulphite in commercial wines, and usually this is because they have been rushed to the market too soon.

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.

What are finings? Do I need to add them?
Finings 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.

What is Bentonite?
It is a mineral earth. It is the easiest and usually the most effective inorganic fining agent. If you want to use finings and don't have a degree in biochemistry, stick with Bentonite! Some winemakers add Bentonite to every fermentation, as a precaution, but I don't recommend this, because, though completely harmless, Bentonite will remove some of the more subtle flavours and scents. Note - Bentonite, though technically an additive, is not an ingredient, as it falls to the bottom and is not present in the finished wine.


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.

What is a hydrometer used for?
A hydrometer is a weighted tube that floats upright, half in, half out of the juice. It has a scale on it which lets you read the Specific Gravity (SG), or density of the juice, as it floats higher in denser liquids. The SG of a juice depends on how much sugar it contains, so the hydrometer is effectively measuring the sugar content of the juice. During fermentation, as the sugar is converted to alcohol, the SG becomes less. The hydrometer is again used to monitor the progress of the fermentation. Finally, it is used to confirm when fermentation has stopped, and the comparison of initial and final SG is used to calculate the alcoholic strength of the finished wine. (For more details, see the section on Technique Questions)

What is a vinometer?
This is an instrument that is supposed to measure the alcoholic strength of a finished wine. It relies on capillary action - the tendency of a liquid to climb inside a narrow tube, or capillary, to a height that depends on various factors, including surface tension, viscosity and specific gravity. It works reasonably well with very dry wines, but with sweeter wines the dissolved sugar affects the result. Being a capillary, it is a difficult instrument to keep clean, and any deposits on the inside will also affect the capillary action. Don't bother buying a vinometer. The right way to measure alcohol content is with before and after hydrometer readings.

What is a fermentation trap?
This is a device to allow fermentation gases (carbon dioxide) to escape from the fermenting vessel while denying access to airborne micro-organisms, dust particles and even fruit flies and other insects that can be attracted by the aroma. There are several designs, but most rely on causing the gases to bubble through water (or sterilising solution). You need one if you are fermenting in the traditional glass demijohn fitted with a cork, but if you are using modern disposable plastic drinking water containers, it is sufficient to use the screw cap, backed off half a turn to allow the gas to escape through the screw thread. Nothing can enter against the steady stream of carbon dioxide.

What is the best kind of fermentation heater?
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.

What is a fermentation jacket?
This is just a lagged insulating jacket that wraps around the fermentation vessel. It relies on maintaining a good temperature by trapping the heat generated naturally by the fermentation process. Unfortunately it can be self defeating as the trapped heat can lead to temperatures that the yeast can't survive. Also, the jacket takes away the pleasurable and educational experience of watching the fermentation. Lagging jackets are best left to hot-water cylinders!


  1. Hi Dave - If I want to make 4 ltrs of 100% grape juice - not from concentrate - in a 5ltr demijohn, how much sugar should I use for a dryish wine between 12 - 14 % alcohol?
    Also, if I want to make a larger batch, say, 10 ltr or 20 ltr demijohn I realise I still use the same amount of yeast (1teaspoon or 4 grams) but how much sugar should I use for these larger measures? Thanks for all your help to date. Paul.

  2. Hi Paul - If you look at the chart on the bottom of every page of the blog, you'll see that a sugar content of 240 g/l will yield nearly 14% ABV. If your grape juice already contains 90 g/l then an addition of 150 g/l will do the trick. To give a more exact answer, I'd need to know more about the juice, either from reading the label or measuring with a hydrometer, but 150 g/l won't be far out.

  3. That's Grams per litre right?The juice is 1l Biona Organic pressed grape juice. The ingredients only state its certified organic grape juice. The 'Typical nutritional values per 100ml' info lists energy, fat, carbs, etc 'of which Sugars = 16.0g.That would seem a lot more than the 90g/l?

  4. 1. Can I top up after fermentation/racking with commercial wine instead of water or juice?
    2. When making the juice/sugar syrup to add to the juice/yeast/must - can I add a tea bag (for a few minutes) to the warm syrup mixture to add tannin to the wine?
    3. I plan to age the wine in the demijohn/ airlocked for a few months and then bottle for a couple. If I add a crushed Campton tablet after fermentation has stopped, do you think this will affect the taste?
    4. I will leave you alone now.
    Thanks for your patients and assistance. P

  5. Yes, g/l = grams per litre. As your juice states 160 g/l (which is quite high) you will only need to add sugar at the rate of 80 g/l.
    Other questions:
    1) Yes, topping up with commercial (or home-made) wine is fine.
    2) You could, but you'll get a better tannin extract by making strong tea in a pot or cup with boiling water and adding some of it at the same time as the sugar syrup.
    3) After fermentation, pour or rack the wine off its sediment into the fresh demijohn and cork it. Don't age wine under an airlock. If you add a crushed Campden tablet it will help the aging process, but give it 3 months or more or you will be able to taste/smell the sulphur dioxide.
    Good luck :)

  6. Hi Dave - I have had the good fortune to have met a master brewer who makes wine in his down-time and does some classes, etc. He has kindly sold me (at cost price 20euro) 11ltrs of pure Cab Sav juice imported from a French vin-yard. However - when I was bombarding him with questions he insisted I do not add sugar to this must juice as the natural sugars will give me a wine at 11 or most likely 12%. I would love to get your take on this - will there be natural tannins present in this must juice? He adds finings to his wines - which fining should I use? - Thanks in advance. P

  7. If the Cab Sav juice makes an 11-12% wine - how much sugar do I need to add to bring it up a notch to 14% - 40g/L?

  8. Hi Paul - If you have a hydrometer, check the gravity of the juice. 11 to 12% is quite a big range (75 to 82 gravity or 190 to 210 g/l approx). Your supplier is right in saying 11 to 12% is perfectly acceptable natural strength, but if you want to push it a little you could. but I wouldn't exceed 25 g/l, in case the juice is at the top of his stated range, as high end fermentations around the 14% mark can take a long time to finish. Now, finings. As a commercial winemaker, he uses finings to ensure clarity and to get his wines to market quickly. These are not of such concern to an amateur. But if you want to try it, use Bentonite. Add it at the start of fermentation. It will help it to fall clear as soon as the activity stops.

  9. Oh, and you asked about tannins. Yes, there will be natural tannins present in the juice. Don't add more unless you are planning a long maturing process.

  10. As ever Dave - thanks for your advice. I have a hydrometer although it is confusing - it reads in Blg so I will need to Google how to translate this into a gravity reading. I started my 1st ever batch of store bought juice this week (4ltrs) it had a Blg of 16.5 which translates as potentially 8.5% alcohol (on the chart that came with the hydrometer) so I added 70g/l of sugar (10oz in total) to bring up the % to about 13 - I hope I got my sums right - Let me know if I've totally ballsed this up but I will see what happens. Thanks again. P

  11. Blg or BRIX are used by the industry but most amateurs use gravity measurement which was the standard advocated by the 'scientific winemaking' movement from the start. I looked at your calculations and they are fine. I think you've got the hang of this!

  12. As Columbo used to say,'...and one more thing' - sorry to ask but. I've went for it and started 15ltrs of the Cab Sav juice I told you about. My hydrometer reads 22.5 - 23blg which translates as approx. 12% alc which is why I won't bother with extra sugar. I made a yeast starter on Monday - 3 quarter litre juice with nutrient and 5g yeast which took off pretty good. Yesterday I added the started to the rest of the 15 ltrs juice, covered the opening of the large demijohn with a muslin cloth to let some air in and it's got a good healthy looking head on it today(17th Happy St Pat's Day!!). My question is, do I leave it for about a week and then rack it into a 2nd demijohn and then airlock it for 2ndary fermentation? When do I know when primary is finished? There is a lot of conflicting advice online and my mates seem to be simply winging it to be honest. I'm worried that I might rack it too soon and loose or interfere with the primary process. Any advice is welcome. Paul.

    1. Hi Paul - primary (aerobic) fermentation changes seamlessly to secondary (anaerobic) fermentation over the course of a few days with no clear end point. It's not something you have to worry about. You don't need to rack the wine until the end of secondary fermentation, but don't delay that racking too long, i.e. don't leave finished wine sitting on the lees for more than a week. The only time I would do an early racking would be with pulp fermented wines, to get rid of crushed fruit 'floaters'. Juice wines like yours don't need this extra step.

  13. Thanks Dave - So if I insert an airlock after a few days I can leave it until there is little or no activity in the airlock which would indicate the end of 2ndary? I was wondering if this is a matter of weeks or months and then I rack it from the lees?

    1. Yes, that's right. Replace the muslin with the airlock as soon as you're happy that it's not going to froth over the top. Depending mainly on temperature, the fermentation will take 4 to 6 weeks, typically.

  14. Hi Dave - I've a few vessels of wine bubbling away - a 15ltr and two 4ltr in gallon demijohns. I was wondering:
    - should I ever stir the contents during fermentation?
    - I plan to rack after the fermentation stops in a few weeks or so and was wondering about adding a crushed Campden tablet at this stage?
    - There is a bit of a gap in the 20lts demijohn holding the 15ltrs and I was wondering if I need to top this up with something? Is this really necessary? I could use some of the 4ltr if needs be or rack into 5ltr demijohns (if I can find any, very hard to find in lockdown)?
    - Potassium Sorbate - is this necessary?
    - I've a Vinbrite filter. Is this just as good as finings (I got some bentonite but am reluctant to use it.)

    Your advice is appreciated as ever.

    1. Hi Paul -
      No need to stir during fermentation. The bubbling of CO₂ is all the stirring it needs. You can add crushed Campden tablets at the end of fermentation (not before) at the rate of 1 tablet per 5 litres. The gap above the fermenting 15 litres is not a problem as it is all CO₂ but don't let it sit any more than a week after fermentation stops or you risk oxidation. I prefer not to filter wine as it can lower the quality again through oxidation. Most wines fall clear by themselves. Commercial winemakers filter to get it to market earlier but they use fast vacuum filtration which you can't do at home. Potassium sorbate is a stabiliser. You don't need it if you are fermenting to dryness. It is useful for stopping semi-sweet wines from refermenting in the bottle.

  15. Thanks again Dave - would you recommend topping up the gap if I want to bulk age the wine or should I bottle directly after fermentation and let it age that way?

  16. At the end of fermentation you've got to get it off its sediment. I normally age red wine in 5 or 10 litre glass or plastic demijohns which should be filled to the neck. If you bottle directly you'll get a sediment in every bottle. Not harmful but not very pleasant either.

  17. Cheers Dave - I will let you knw how things go. P


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