A scientist turned engineer, Dave started making wine in 1970. His approach combines simplicity with sound scientific principles.
If you make your own beer, wine or cider you ought to know how strong it is, especially if you are planning to serve it to your friends and family. No-one likes to wake up with a hangover caused by drinks that were stronger than expected. Also, as responsible drinkers like to know what they are drinking, responsible homebrewers should be able to tell them.
The techniques in this article will put you firmly in control of alcoholic strength in your beer, wine and cider production. No more hit-or-miss!
Alcohol by Volume (ABV)
The drinks industry is finally moving away from old and confusing alcohol measurement standards (such as degrees proof) to the much simpler Alcohol by Volume or ABV figure. ABV is expressed as a percentage, and is: (volume of pure ethanol in drink) ÷ (total volume of drink) x 100% By this formula, water has an ABV of 0%, pure ethanol has an ABV of 100% and all alcoholic drinks lie somewhere in between.
The following table shows the typical ABV range of normal commercial drinks. As a general rule, the amateur brewer or winemaker should aim for similar figures, as very weak wines or very strong beers and ciders are not to many people's liking. You'll notice I've not included any 'alcopops' in the table. These are synthesised drinks designed to hook teenagers. They should never have been invented and are not worth discussing further!
ABV of Commercial Drinks
3.0 to 4.5
4.0 to 5.5
5.0 to 9.0
premium & specialist beers
6.0 to 9.0
scrumpy style ciders
9.0 to 11
light table wines
12 to 14
most table wines
15 to 20
fortified wines (ports, sherries)
35 to 45
most spirits and liqueurs
- 15% is the maximum strength achievable by direct fermentation (except under highly controlled and optimised laboratory conditions)
- Fortified wines are strengthened by the addition of brandy or some other spirit before bottling.
- Spirits achieve their high alcoholic strength by distillation, using heat, evaporation and condensation to separate the alcohol from the water. Don't try this at home. It is illegal in most countries and can be dangerous.
How Do I Aim for a Particular ABV?
The first thing to understand is that all of the alcohol in a fermented drink comes from the sugars in the unfermented juice. Yeast is simply a biological agent that releases enzymes that convert the sugars to ethanol and carbon dioxide. If you know how much sugar is present before you add the yeast, you can simply look up a table to see how strong your wine or cider could turn out.
The sugar content of the juice tells you the maximum theoretical alcohol yield if you ferment through to complete dryness. In practice, you will always come a little short of the theoretical maximum. Here's why:
- There will always be a little unfermented sugar left in the end product (good!).
- Fruit juices are complex and contain many types of sugar. Most are fermentable but a few are not.
- Alcoholic fermentation is not a simple sugar to alcohol conversion. It also produces smaller quantities of aldehydes, ketones, esters, etc. (good: They add to the flavour and aroma!)
- Different strains of yeast have different conversion factors and none achieves the theoretical maximum.
How Do I Aim for a Particular ABV?
The good news is, I have done the research for you and created the only calculator chart you will ever need as an amateur brewer or winemaker. The calculator relates sugar content to the practical, achievable Alcohol by Volume, using a typical general-purpose wine or beer yeast and working within normal parameters. Here it is:
Sugar to Alcohol Calculator
- Alcohol by Volume (ABV) stops at 15%, the upper limit for fermentation.
- Original Gravity (OG) is easily measured using a hydrometer.
- Sugar content is measured Internationally in grams per litre.
- US winemakers might prefer to work in American ounces per gallon.
- UK winemakers: Don't use the ounce/gallon scale. US gallons are different!
- Sugar Content of a supermarket fruit juice is obtained by reading the label!
Read More From Delishably
Using the Sugar-to-Alcohol Calculator
Example 1: Cider From Supermarket Apple Juice
I have a flagon of supermarket apple juice and want to make a cider. The 'nutritional information' on the label gives quantities per 100 ml serving, and includes: 'Total carbohydrates, 11g'.
Now, the only carbohydrate in apple juice is the sugar, so we have 11g sugar per 100 ml juice which equates to 110 g/l. A quick look at the calculator shows that 110 g/l is equivalent to 6.3% ABV, if fermented to dryness. Ideal. No need to add sugar. If I stop the fermentation near the end, I'll have a nice medium-dry cider of around 6% ABV.
Example 2a: Wine From Grape Juice, International Measures
This time the label on the grape juice carton says 14g sugar per 100ml juice, or 140g/l. The calculator tells me that 140g/l will give only 8% ABV. But I want a wine of 12%. The calculator says I need 210g/l for 12%. So I need to add sugar at the rate of 210 - 140 = 70g/l.
Example 2b: Wine From Grape Juice, American Measures
The label on the grape juice carton says 2¼ oz sugar per pint juice or 18 oz/gal The calculator tells me that 18 oz/gal will give only 7½% ABV (approx) But I want a wine of 12%. The calculator says I need 28 oz/gal for 12%. So, I need to add sugar at the rate of 28 - 18 = 10 oz/gal. Dear friends in America, International units really are much simpler to use!!
Example 3: Beer From Malted Barley
This time there's no label to help me. I boil up the malted barley (malt) in my ten-litre boiler to extract all the sugars. I strain it off and let it cool to room temperature then measure the Original Gravity (OG) with a hydrometer. It reads 20. The calculator tells me the sugar content is 52g/l which can yield only 2.9% ABV. My target for this beer is 4%, which requires 72g/l. Therefore I need to add sugar at the rate of 72 - 52 = 20g/l
Reading the Label
In Europe and the Middle East, nutritional information must be displayed on the label of all food products, including fruit juices. As the standard serving is 100 ml the conversion of grams per serving to grams per litre (g/l) is a simple multiplication by ten. This Nadec brand of apple juice has 10.8 grams carbohydrate per serving or 108 g/l sugar.
In America, the nutritional information is often less clearly presented, mainly because the scientific units (grams per litre) are used for the sugar content, but the standard measure is often quoted in fluid ounces, typically 8 fl oz.
US example: This label (above) states the serving size is 8 fl oz or 240 ml. (1 fl oz = 30 ml). Sugar per serving = 25g. Therefore sugar content in g/l = 25 ÷ 240 x 1000 = 104 g/l. At this stage, you can either continue with grams per litre (recommended!) or you can simply drop down on the calculator chart to the oz/gal scale which gives 104 g/l = 13.5 oz/gal. The choice is yours!
If you come across fruit juices that do not carry meaningful nutritional information, my advice is to steer clear of them. If you don't know what's in it, why on earth would you want to drink it!
Also make sure that somewhere on the packaging it clearly says 'no preservatives', With preservatives present, the chances are that fermentation simply will not start. Besides which, who wants to drink preservatives?
- Remember that the calculator shows the ABV obtained if you ferment to dryness. If you stop early, the result will be less strong and slightly sweet.
- It's best to aim for 12 to 13% for your table wines. Aiming for the maximum 15% often results in a stuck fermentation, weak and hopelessly sweet, unless you are very careful with yeast nutrients, temperature and total acidity.
- Brewing is not an exact science. There are always some unknowns that can affect the result. But it should not be hit-or-miss either. The information in this article is enough to put you firmly in the driver's seat. Make what you want to make by design. Don't put your trust in luck or 'recipes'.
Thanks for reading!
Questions & Answers
Question: If I wanted to ferment pineapples, apples etc, how long do I need for 'complete dryness'?
Answer: There are too many variables to give an exact answer, but as a rough guide: a dry 5% beer, cider or 'fruit cider' takes about a week; a dry 13% wine or fruit wine takes about 4 weeks. Stronger wines at 15% could take 6 to 8 weeks. But these times depend on temperature. Below 20C, fermentation is noticeably slower, while above 28C you risk killing the yeast.