Fruit wines related questions

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Jul 5, 2008
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I have been reading quite a lot of books and online material recently about making fruit wines, and have a number of questions:

1. How can I calculate the total amount of sugar I need to add? It is quite difficult to measure SG for many fruits which don't contain large quantities of water. Assuming that I have the initial SG, how do I determine the amount of sugar to add for sweet/dry wine? (if you could specify the actual SG values it would be great)

2. Is it recommended to add the sugar in 2 steps or to add it all in the same time? How can I determine when to start using the air-lock? (if according to SG, what should it be?)

3. Do yeasts produce alcohol before the phase of closing the wine in a demijohn with air-lock?

First of all you should get a recipe for the fruit wine you intend to produce. That will give a good reference starting point for the sugar then you can make additions according to the hydrometer. I personally add all the sugar I'll need when I start the batch. The only reason to make sugar additions during fermentation is to get a very high alc. content.

If the wine is allowed to completely ferment (use up all sugar) you'll will have a dry wine. After adding sorbate you can add sugar to taste for a sweeter version.

Move from the primary fermenter into the secondary when the SG is 1.001+/-.

Alcohol production begins when fermentation begins and continues until all the sugar has been consumed or until the yeast has been killed off by a high alc. content.
The addition of sugar is needed when the natural sugar is not enough to make an adequate ABV (Alcohol By Volume) or if you want a higher alcohol wine. Often times with fruit wine (other than grape) the natural sugar is not enough. The only way to know for sure is by measuring either SG (specific gravity) or Brix.

I prefer Brix. For each Brix measurement multiple the brix times .55 to get an estimate of the potential alcohol. So if the starting brix is 10 then your potential alcohol is 5.5% (10 x .55). If you want to produce a wine with an alcohol content of 11% then you need to raise the brix from 10 to 20 (20 x .55 = 11%). To do this add 1.5 oz of sugar per gallon for each 1 brix increase. In this example, assuming 1 gal you would need 15 oz (10 x 1.5 oz) or roughly 1 lb of sugar (3 gal would require almost 3 lbs of sugar and so forth). You can convert the measurements to SG using the chart below.

Attached is a chart that shows SG and Brix and the required sugar addition needed.

I add my sugar at one time after the yeast has started to take hold, some people prefer to add it in stages.

As for your last question, you want to wait until the fermentation is just about completed before transferring the wine to a demijon with an airlock. The reason is that if fermentation is still vigorous the airlock will either be pushed out or fill with juice.

Specific Gravity & Brix Chart.jpg
Hey guys, thanks for your help.

Regarding the amount of sugar - for grapes, watermelons etc.. it is very easy to measure the SG. However, when I start making wine from a fruit such as plums it is a lot harder since it is difficult to extract enough juice to measure with hydrometer. I wanted to know if there is a better way to measure SG than extracting the juice. For example, let the yeasts work for a day or two and then measure SG, let pectic enzyme work on the fruit and then measure etc...

From your answers I understand that you both rack into the secondary fermenter (with airlock) when fermentation is almost done. Doesn't it increase the risk of spoilage/oxidation?
As long as there is still activity coming from the must there is little or no chance of spoilage. Once under the air lock a blanket of CO2 prevents oxygen from entering and causing spoilage...hence the air lock.

Get a paint strainer bag from your local hardware store and place it in the primary container then place your crushed fruit in it. This allows you to get a sample of must from outside the bag where there will be less pulp and you'll have a cleaner sample to check the SG.
You can't accurately measure brix or SG after fermentation has started. Even after 1 day their could be a significant drop in sugar (as much as 10-20%). I can think of two ways for you to measure the SG prior to fermentation. Simply wait until the next day to take your initial reading and starting fermentation. You should then have enough juice for your sample. The other way, which is more expensive, is to buy a refractometer. A refractometer is what is used in the vineyards to test the brix prior to harvest. You only need a drop of the juice which is more convenient when you are in a vineyard than trying to squeeze enough grapes for a sample, especially if you are testing multiple vines.

The least expensive refractometer will probably run close to $60 but will last a long time. Here is a link:

Refractometers cannot be used to measure brix after fermentation because the alcohol already starting will give you an inaccurate reading. So you can only use it prior to starting fermentation.

When you transfer the wine to the demijon you want to make sure you leave very little head space, which is why you want to wait until the fermentation is nearly completed before doing so. When you have a large surface space between the neck of the demijon and the wine is when you will run into trouble with oxidation. It doesn't take long for oxidation to start occuring. Once you notice the bubbling from the airlock has stopped then it is time for your first dose of potassium metabilsulfite or use a campden tablet. Some people recommend the addition of sulfite every other racking. I like to add a reduced sulfite addition at each racking since air is being incorporated each time you rack the wine.
I haven't tried using a paint strainer, only a "regular" kitchen strainer. I might try using one.

I liked the refractometer suggestion. It was in my list when I started collecting equipment and for some reason I forgot all about it. Does it have limitations except having no alcohol in the juice?

I usually leave enough head space in the demijon for the yeasts to make as much foam/bubbles as they want. Usually it depends on the amount of fruit I have. In order to prevent oxidation I use CO2.

What dosage of potassium metabilsulfite do you use? My recipe says 0.1 gram per liter but sometimes the yeasts don't get the message :).

In general I try to use as little chemicals (potassium metabilsulfite, DAP etc..) as possible, especially since I am not too sure about the maximal dosage.
For example, as far as I know DAP may have a role in creating carcinogens in some cases, so I started using even less than my recipe says.
I only used DAP once and then switched over to Femaid and Go Ferm. Steve pointed out that Fermaid and Go Ferm are US names and may not be available in Canada, not sure if that is where you are. Yeast nutrients are not chemicals. You could probably Google them to see what they actually contain. Often times yeast needs nutrients.

I don't know of any other limitations with the refractometer other than when fermentation starts.

As for potassium metabisulfite (meta) additions, I use a 10% solution that I can store for several months and not have to worry about measuring out the powder each time I want to use it. To make a 10% solution add 75 g (about 12 tsp) of meta to a 750 ml bottle, fill it 1/2 way with warm water, shake to dissolve and then fill the rest of the bottle with cold water.

50 ppm which is the addition generally added to the must before the yeast to help keep the natural yeast at bay would be 3.33 ml of the solution per gallon or .88 ml per liter.

10 ppm = .18 ml/L or 0.67 ml/gal.
30 ppm = .53 ml/L or 2.00 ml/gal.
50 ppm = .88 ml/L or 3.33 ml/gal.

For higher amounts you can do the calculation, e.g. 100 ppm would be .88 ml x 2. Just don't forget to multiple the amount of solution needed by the number of liters or gallons of wine.
Actually, the yeast nutrient that I used to sell in my store was just DAP (di ammonium phosphate). Even some of the yeast energizers contained DAP.

I mostly got these products from Vineco and Spagnols, but also ABC Cork.

... Steve pointed out that Fermaid and Go Ferm are US names...

50 ppm which is the addition generally added to the must before the yeast to help keep the natural yeast at bay would be 3.33 ml of the solution per gallon or .88 ml per liter.

I sent an email to Lallemand and asked them about Fermaid & GoFerm in Europe. I believe they should be sold here under the same brand name, but I'll wait for Lallemand's reply.

How much meta should I use to stop fermentation when I decide that the wine has enough alcohol and I want to prevent the yeasts from consuming all the sugar? Am I right to assume that 50ppm is the number?
What is the limit of the total amount of meta that can be safely added to the wine? (for example, can I add it both before and after fermentation and in what dosage?)

Thanks for your answers. You and Steve have helped me a lot.
Last edited:
Sorry to break in like this.
hey i am back from holliday in France.
I was in the Jura part but drove through burgundy.

Anyway back to the question.

You can not stop fermentation by adding sulphite.
Well actually you can but then you would need so much
that the wine would be undrinkable.

Sulphite will stun yeast for some time but afther that
the sulphite levels will get low again and the yeast will
restart fermentation.

They way to go is to make a dry wine and sweeten it afterwards.

So wait until the SG has dropped below 1000.
Wait until the wine has cleared.
Rack, and wait some more.

Then add sugar to the desired level and add sorbate
and sulphite.
The sorbate will prevent any living yeast to multiply
and the sulphite keeps bacteria under control.

Hi Luc, your input is always welcome. Luc is correct in that you cannot stop a fermentation by adding sulfite, you would also have to cold stabilize the wine and then microfilter it and even then it's not guaraneteed the yeast will not become active agian. The best thing to do is ferment to dry and sweeten later.

Each time you add sulfite only a percentage of the sulfite becomes bound to the wine, the rest dissipates out over time which is why just adding it once is not enough to protect the wine over time. White wines require higher dosages then red wine. The pH of the wine is also a factor in how much sulfite is needed. To really determine how much sulfite is needed at each racking to protect the wine you need to measure the "free" SO2 level so you know how much more to add. This is complictated but can be done with titrettes (although I have not had much luck with them).

50 ppm before the fermentation is just enough to stun the wild yeast to give the added yeast time to take hold. By the end of fermentation the sulfite added will have dissipated out from all the co2 gas being pushed out of the wine. As for safe levels, if you add to much you will certainly know it by the ordor in the wine. What I do for red wine is after fermentation is completed I add 50 ppm then at each racking I reduce it to 25 ppm. Since I only do 3 rackings I know I have not over sulfited my wine. For white wine I start off higher anywhere from 75-100 ppm and then reduce to 1/2 at each racking.

Here's an excellent guide that is easy to read.

Also, here is a website with awesome articles:
I am glad I found this forum. I know I still have a lot to read but I never thought I was doing so many things wrong :) .
I started making wine by following recipes that my father got when he took a very short course. They specifically say to add sulfite in order to kill the yeasts before they consume all the sugar, add sugar in 2 parts (which you say is not necessary) etc... Maybe I should do some deeper fact checking before I follow these recipes.

Anyway, the last piece of info about the sulfite explains a lot. A few days ago I opened a bottle I made a year ago and found it was fermenting again (after I was sure the yeasts were long gone). Luckily it was the last of its batch... :)
I like to say that we learn from others so we can learn for ourselves. You could simply crush fruit, let the wild yeast do the fermentation, rack and drink it without adding commercial yeast, nutrients and sulfites but you will never be able to make a consistent wine year to year. Plus, wild yeat may not be sufficient to finish fermentation thereby ending with a stuck fermentation at a sugar level that is undesireable or too low of alcohol. Wild yeast can also end up giving hydrogen sulfur (HO2) odors becasue there is not enough nutrients for the yeast.

The first time I had 40 gals of zifandel turn out undrinkable I started doing all the reading I could of the wine making process and making changes each time. I am now producing some pretty good wines and having more fun with what I call the science part of wine making. My dad would say to me, well this is the way the old timers used to make wine. Yes, but many of them did not have the benefit of learning new and improved ways.
Alcohol content?

:eek: I added plenty of sugar to my rasperry wine and racked after 5 days per the recipe, although the SG was .990, not the 1.030 the recipe said it should be. I also tasted no alcohol at all when I did the first racking from the primary to the secondary. Is this normal?
This was my first non-kit wine, and like an idiot, I did not remember to take the starting SG:(