Deacidify: fruit wine too tart, sour

My fruit wine is too tart and sour. It contains too much acid. How can I deacidify my fruit wine?

With this article I would like to offer help with the deacidification of fruit wine. My fruit wine contains too much acid. It tastes too tart and sour, what can I do?

Every hobby winemaker has come to the point where the fruit wine just tasted too sour and you wanted to deacidify it. The bad news is that there is no such thing as a magic bullet. The simplest method is to dilute it with a less acidic drink, mostly fruit juice or water. Or sweetening with sugar or fruit syrup.

A concrete example would have to be known to provide concrete assistance. I don’t think much of recipes unless they are tried and tested and they are statistically robust. Good recipes can compensate for the variation in ingredients and bring the tolerance of the variation to an acceptable level.

A historical recipe for such a wine was the colorfully mixed vine seedlings in the vineyard from which the mixed batch was then pressed. A robust mix of different components, which in total showed a slight deviation. Mild varieties dilute the sour and sweet varieties the tart ones. In the end, the result was a mixture, an average. With a good choice of varieties, there was a wine harvest every year. The aim was to achieve an approximately similar result with pressed wine without experiencing any major surprises. Unless there were natural disasters but even then one hoped for at least some types of income. So this colorful mix was also a kind of assurance that at least something could be pressed at the end of the year. Always a little different but always very similar.

  • Problem area: fruit type, juice and acidity
  • Analytics in winemaking
  • Deacidify grape juice
  • Total acidity in the wine during the grape harvest
  • The grape variety determines the result
  • Wet sugar in fruit wine
  • Minimum content of sugar-free extract
  • Calculation examples for fruit wines
  • Ideal compositions of total acidity and extract content
  • At the beginning determine the result

Problem area: fruit type, juice and acidity

In the classic fruit wine recipes, the acidic fruits are a particular problem. The second problem is that lactic acid or citric acid should often be added. Problem number three is the amount of fruit and, consequently, fruit juice.

We usually work with tables that take into account the juice yield factor (unless we are already working with raw juice) and the sugar-free extract. The juice yield can also be determined empirically and is between 70% and 80% for stone fruit and soft fruit.

The sugar-free extract is mentioned in some books, but it is rarely discussed directly in the wine recipes. Many fruit wine recipes also work for the sake of simplicity. There is basically nothing wrong with that. There are good and not so good recipes. However, if you want to work precisely, you must calculate precisely.

The sugar-free extract is a quality criterion for the fruit wine. It also quantifies how much the raw juice was diluted and how much glycerine was formed during fermentation and how high the mineral content and the content of all other dissolved substances in the wine are. The only problem with this is that this value can only be determined by laboratory analysis.

This means that hobby winemakers are flying blind. However, this is not so bad if you heed the principle not to dilute fruit juices too much. This point in particular is difficult for ambitious hobby winemakers, as many recipes aim to achieve the largest possible yield of fruit wine. Some websites that offer assistance in fruit wine production also often recommend far too little fruit in their fruit wine recipes.

Analytics in winemaking

So how important is analytics in winemaking? How complicated should it be? Analytics is important, but not as important as you might think. It is even relatively unimportant to know numbers exactly. You can and should continuously expand your knowledge. That never hurts. But the basics are sufficient for understanding. Anything beyond that is nice to know, but less helpful. Many hobby winemakers are neither chemists nor technologists and would like to make their own wine at home simply and easily. The goal is that it should taste good. Very few people care about knowing exact numbers. Numbers are important if you want reproducible results and want to hold on to what worked or where you should change something if not.

Oechsles spindle and refractometer are probably the most useful tools. If you are making wine on a regular basis, they are essential and I would recommend them to anyone. An acidometer to determine total acid is nice but not essential. It’s not about knowing exact numbers. Exact numbers are only useful if the user knows what to do with them. If you want to know exactly and can do something with these numbers, please feel free to analyze and measure. If you want to make good wine from grapes and have the appropriate prior knowledge, then you will probably fall back on all the information that you can get.

Deacidify grape juice?

Grapes show a relatively large range of fluctuations in degrees of ripeness and can really only produce good, harmonious, dry wines when fully ripe. At this maturity, the sugar content and the acidity are in a good ratio and will almost certainly result in a harmonious wine. Smaller edges can then be removed using fine deacidification, if necessary at all.

If you know your grape variety and have literature and information about it, the expected sugar content and the average acidity are usually listed. There are also grape varieties that do not rise above 75 ° Oe and whose acidity decreases steadily as they ripen. A lot of know-how is required in grape wine production. Know your grape variety and you will almost certainly get a good wine result.

If the construction sites are too large at the beginning of fermentation, i.e. too much acid and too little sugar, the grapes should still be hanging on the vine and allowed to ripen. Here it is usually sufficient to observe the sugar content and, to be on the safe side, to measure the acidity of a representative subset (of individual berries from different grapes on the whole trellis) in the acidometer.

Is it really necessary? Not really if you know the grape variety and its ripeness profile or have experience. You can work with thumb times pi. But we’ll see right away that thumbs up is not really effective and that laypeople can fail.

Total acidity in the wine during the grape harvest

8g / l total acid is a good value for white grapes for harvesting at approx. 80 ° Oe. The acidity decreases by approx. 1g / l-2g / l when the wine is made, because some of the tartar precipitates. A homeopathic fine deacidification of 1g / l is then still possible and does little damage to wine.

We have had grape juices with about 60-70 ° Oe and 12-14g / l total acid and grape musts with 100 ° Oe and 6g / l total acid. The addition of sugar is not a problem with hobby wines. The deacidification does. The first juice would even have to be deacidified with the same amount of water. That is totally unacceptable!

In the case of grapes, potassium or calcium salts are used, which form a firm bond with the excess tartaric acid. The result is that the insoluble salt of tartaric acid, potassium tartrate or calcium tartrate, precipitates. The tartar we know.

The addition of water to grape wine is not allowed in Europe. It was not always like this. Gallizing, i.e. the addition of wet sugar, was still common at the beginning of the 19th century. The same goes for the production of pomace wine or house wine.

The addition of water reduces the acidity without raising the pH too much. Now it’s getting a little chemical. Water is an extractant and increases the ash content of the wine. The pomace is therefore leached more strongly due to the strong difference in concentration of the solutions and this unnatural increase can later be used to check grape wine for the unauthorized addition of water.

If you want to work without water, only a double salt deacidification would work. I do not recommend this approach to anyone, especially laypeople and hobby winemakers. The effort including the costs and the know-how is not related to the benefit. I would only harvest the grapes when the rise in Oechsle degrees no longer increases significantly.

If these measured high acid values ​​are the last of the feelings at the end of September, you will have to consider whether you really want to make wine from these grapes. Other processing options are often more effective: grape juice liqueur, jam, jam, jelly or grape juice. Normally, when the grapes are fully ripe, the acidity levels are harmonious and no longer need major corrections. But that always depends on the grape variety, which can range from American vines to hybrid vines to the classic Vitis Vinifera. In house gardens you can sometimes find many idiosyncratic grape varieties from which good wines can only be produced with a lot of effort.

The grape variety determines the result, not the winemaker

We also had to painfully discover and learn: not every grape variety is suitable for every type of wine. The hobby winemaker should consider that. There are grapes for Federweißer, sparkling wine, table wine, quality wine, Prädikatswein (Spätlese, Auslese, Eiswein). There are also grapes for sherry, vermouth or brandy. The same goes for blue grapes, which are better processed into rose wine than red wine.

But you can use grapes for anything? Well that’s true, at least in principle. However, there are grape varieties that ripen early and whose berry skins tend to burst when it rains in autumn or whose sugar content no longer increases significantly. Such grape varieties are often used for Federweiss, as the wine is not used for further expansion anyway. There are also grape varieties that degrade quickly in terms of taste and are therefore more suitable for quick consumption than for wine storage. Acid-rich blue grapes are always better used as rose wine. If you were to make red wine from it, you would have to deacidify with all the tricks and tricks and make the result drinkable.

An intervention is always only a makeshift emergency solution. Work with nature and create something that works from it. This will save you a lot of trouble. The winemaker only accompanies, he also controls a little, but he is not a magician.

Instead of adding chemicals and deacidifying agents, it is advisable to dilute the private house wine with 10% water in the hobby area. If a longer maceration time or maceration is planned, this is usually not a problem. This saves arithmetic and a possible negative result due to over-deacidification, pH value increase, etc. If one can and wants to live with this little trickery.

In the case of galling (the process of wet sugaring) and in the hobby winegrowing literature, there is even information that wet sugaring of up to 30% is possible. That is quite a lot, but brings a wine with 10g / l total acid to approx. 7.6g / l. That is quite remarkable. However, this also reduces the extract content slightly (20g / l to 15g / l) and the wine becomes a wine, a better spritzer, if you will. If you only want a drinkable result, that is definitely a possibility. I am thinking here of a feather white. It is not stored and consumed quickly and could also be diluted with water in the glass.

Gallizing was still practiced into the 19th century with the pale aftertaste that the quantities of wine had increased and the result was not necessarily crowned with quality. So you shouldn’t expect a top wine any more. But if you want to produce a drinkable house wine for private use, it is definitely an option.

Producing grape wine like a professional is the supreme discipline. For the technocrats and everyone who wants to be very precise, there is again specialist literature, calculations and chemicals. It is entirely possible to deacidify with CaCO3 or K2CO3. I don’t want to go into that here. Keep it short and simple. You should also keep in mind that some tartar build-up will also form when the wine is stored. It makes sense to deacidify the juice, since interventions have less of a taste effect, but for laypeople it is difficult to estimate how the wine will be in the end and whether the deacidification was not already too much. This then leads to a low-acid wine that is susceptible to wine diseases. It’s about know-how. You have to be familiar with what you are doing.

For laypeople I only want to give basic information here. Of course, Gauling is frowned upon and has long been banned in the commercial sector. The wine industry suffers from overproduction and it is more important to produce high quality wine than to get more wine yield.

Grape musts from normal vintages that come from fully ripe grapes do not need to be corrected. Only a slight addition of sugar to achieve 12-14% vol. Alcohol is necessary if higher-grade wines are intended. However, wines with 10% vol. be appealing. Cabinet wines from our own garden. Every hobby winemaker should work towards this. Natural wines without much processing. This also supports the KISS principle, keep it short and simple.

If the grape material is good, good wines are made from it. Therefore, it is usually sufficient to neglect the acid content and concentrate on the Oechsle content. If this value is as high as possible in mid-September, a grape harvest can be considered. To be on the safe side, do an acid test before the harvest (to avoid any nasty surprises) and look forward to a good vintage. If the acid content is actually too high, nothing can avoid deacidification. In southern countries, the acidity will be more interesting, as it decreases more at full maturity. Reaching high sugar contents is usually not a problem here and acid will have to be added.

Wet sugaring of fruit wine – common practice and permitted

Fruits are usually in an area with less variation in their ingredients and the mashes are mixed with water and sugar. In addition, fruit wine is usually made with residual sugar. This partially masks excess acid. This is why certain fruit wine recipes work quite well.

But what interests us in terms of extract content and deacidification are primarily the positively charged ions such as potassium and calcium. If you throw deacidifying lime into a fruit mash, only the pH value is raised, which leads to browning, loss of taste and the drink becomes too salty. The salts of the acids are formed, but they do not form firm bonds. Everything remains in solution and the acid neither precipitates nor is it significantly reduced. But we intend to reduce it. Except for rhubarb, because the oxalic acid also forms a strong bond with the lime and calcium oxalate precipitates.

What is important to us is the buffering effect of the solution. The more a mash or a fruit juice is diluted, the fewer potassium ions and minerals are in solution. Potassium is usually found in the skins of grapes. But it is also present in all other fruits. With longer maceration, the fruit is more leached and more substances go into solution. All of these substances increase the buffering effect of the solution. The drink becomes more and more substantial.

Some recipes assume 4kg of fruit for 10L of wine. In my opinion, such dubious recipes can always be calculated very precisely. If the fruit has a sufficiently high sugar-free extract, it can of course be diluted without any problems. Except for mountain ash, which is around 200g / l sugar-free extract (zfE), all other types of fruit are relatively low in extract. Most berry juices are at 20-40g / l ZFE.

Minimum content of sugar-free extract required

In Austria, a minimum content of 12g / l for the extract residue is required for commercial cider. The sugar-free extract is made up of total acid, calculated as malic acid, and the remaining extract. The minimum acid content is 4g / l. That means, if you add both values ​​as a minimum, you would get 16g / l zfE. If an apple juice has around 20-28g / l ZfE, a greater dilution is no longer possible. Therefore, cider wines are usually made without the addition of water, just like grape wine.

Berry juices must be forcibly diluted. However, the total acidity makes it relatively difficult to produce dry products. Unless you accept that they taste thin and with a higher alcohol content they are smoky. With water, the acid is reduced but at the same time the extract content is also reduced. In commercial production, one would like to prevent overstretching of fruit juices and guarantee the consumer a minimum juice content in the fruit wine. Otherwise only flavored, colored water would be sold.

To prevent the extract content from decreasing too much, Fruitwinemaker in the USA use a simple trick. You rely on blending with base wines. This is where our calculation comes in. There are at least two fruit wines that have good extract values ​​but low acid content. This is cider on the one hand and pear wine on the other. Whereby pear juice sometimes tastes more neutral than apple juice and can be added directly to the mash instead of water when making fruit wine.

Calculation examples for fruit wines

Simple example:

black currant juice approx. 30g / l acidity 30g / l extract

Pear juice approx. 5g / l acidity 30g / l extract

Fruit wine made from 1 part currant juice and 4 parts pear juice

Acid: 30g / l + 4x5g / l = 50g / l: 5 parts = 10g / l acid

Extract: 30g / l + 4x30g / l = 150g / l: 5 parts = 30g / l Extract

Currant juice >>> 70-80% yield >>> approx. 1.5kg currants, black

Since we want a little more color from the black currants, we simply round up to 1.5kg. Of course the numbers are not exact. For that we would have to determine the acidity. The acidity of currants is between 24g / l and 37g / l and of pears between 4g / l and 7g / l. This is sufficiently precise for our example. The high extract also allows it to be diluted with water if the finished wine turns out to be too acidic without the wine losing any significant amount of extract. This is a robust recipe. The fruit wine is, however, intended as a residual sweet dessert wine. Therefore it also has 10g / l acid, which it tolerates quite well.

Now we calculate the deviation:

black currant juice approx. 24-37g / l acidity 30g / l extract

Pear juice approx. 4-7g / l acidity 30g / l extract

Fruit wine made from 1 part currant juice and 4 parts pear juice

Acid: 24 to 37g / l + 4x (4 to 7) g / l = 40 to 65g / l: 5 parts = 8 to 13g / l acid

Extract: 30g / l + 4x30g / l = 150g / l: 5 parts = 30g / l Extract

We see that the acid is in the range of 10g / l +/- 2g / l. If the wine is too acidic, it can be corrected by adding 10-20% water. This lowers the extract content a little, but this value is still high enough to survive this procedure without any problems.

However, when measuring the acidity, we will find that the acidity is more likely to be in the range of 10 +/- 1g / l and is therefore closer to 10, because the juices are usually more in the middle range than the extreme lower or upper edges of the acid scale.

Why is no acid added here? We don’t need them because we don’t overstretch our mash. We have enough acidity in the wine base and we will find that it does not taste inharmoniously in finished wine.

The counter-argument is that you want single-fruit red currant wine and not a multi-fruit wine, which consists largely of pear juice. Yes I understand. Therefore another example with a water dilution. The sugar required for the wine is of course already dissolved in it. We choose currants because they are the most common berries from the home garden for fruit wine production.

The same example with the black currant juice with water

Fruit wine made from 1 part currant juice and 2 parts water

Acid: 30g / l + 2x0g / l = 30g / l: 3 parts = 10g / l acid

Extract: 30g / l + 2x0g / l = 30g / l: 3 parts = 10g / l Extract

Currant juice >>> 70-80% yield >>> approx. 1.5kg currants, black

The extract value in this example is already quite low. However, this should not be further diluted. Because that’s exactly the point I’m getting at.

If you now assume a currant juice with 24g / l or 37g / l, you get this result:

Acid: 24 to 37g / l: 3 parts = 8 to 12g / l acid; 10g / l extract

It is always recommended to set the acid content to around 7g / l. What happens now Yes, it is diluted again. We assume one liter of currant juice with 8g / l acid or 12g / l acid.

Acid reduction from 8g / l to 7g / l reduces the extract content from 10g / l to 8.7g / l. Volume = 1.14L

Acid reduction from 12g / l to 7g / l reduces the extract content from 10g / l to 5.8g / l. Volume = 1.7L

We reduce an already low-extract berry juice even further and increase the volume by up to 70%. Of course, the wine yeast forms some glycerine during fermentation and increases the extract content a little, but the liquid is very, very thin. Adding some residual sugar masks the missing body a little, but that doesn’t change anything. The fruit wine is not very rich. In addition, in my experience, the thin wines are more prone to oxidation and they taste empty.

For me, one of the reasons why one cannot make great wines from single varieties. They are always somehow out of balance and have to be sweet to at least control the acidity. Adjusting residual sugar can also be problematic for laypeople. A residual sweetness of 50-100g / l can be completely sufficient for fruit wines with 8-12g / l total acid. Only very few fruit wines are absolutely dry after fermentation and a residual sugar of 20g / l can certainly be present but cannot be determined in terms of taste. A laboratory analysis would also be necessary for the exact residual sugar. How high the residual sugar should be is also a question of personal feeling. Here you should sweeten slightly and then test the result. The easiest way to do this is with sugar syrup, which is already isomerized when cooking, and test approaches to find the right dosage. The wine is then normally sweetened with household sugar.

Which compositions of total acid and extract content are natural and should be aimed for?

Red wines have between 4g / l and 6g / l and white wines between 6g / l and 8g / l total acidity. But you should also note that grape wines have between 20g / l and 30g / l extract. If you want to draw conclusions about fruit wines from this example.

Fruit wines, if they are dry, semi-dry or sweet, are also well chosen with 7g / l total acid. Unfortunately, most of them lack extract when diluted with water. The side effect is that there is less buffer effect and acidic drinks taste even more sour than expected. The effect is less pronounced with residual sweet wines. But with higher percentage fruit wines, these can appear relatively smutty and inharmonious. A bit like vodka with a bit of fruit flavor in it.

For a good harmony, I would also recommend an extract content of at least 20g / l. If I am not mistaken, minimum requirements of 16g ​​/ l apply in Germany for the extract content in the commercial production of fruit wines. If you want to produce a substantial hobby wine, it is also advisable to adhere to these guide values ​​as much as possible.

Since hobby winemakers often do not have enough fruit available or like to save and stretch the juice to increase the yield, here is a final example. We make raspberry wine according to the fruit wine recipe with only 4kg raspberries / 10L ~ 3L raspberry juice.

Raspberry juice ~ 15g / l acid, 20g / l extract

Acid: 3 * 15g / l = 45g / l: 10 parts = 4.5g / l acid

Extract: 3 * 20g / l = 60g / l: 10 parts = 6g / l extract

Here we have a classic example where acid should normally be added. Usually around 20g citric acid or 30g lactic acid (80%) on 10L of wine. This is actually a prime example of a low-extract fruit wine. Many recipes target these drinks.

If you proceed without a plan and on top of that with a bad recipe, the addition of acid may even have been recommended in the recipe as a precaution. This can be fatal with a currant recipe or sour cherry recipe. So you add fruits, acid and sugar. This means that the wine will definitely be too sour in the end. It is almost impossible to save it. Often, however, it is also the case that sugar has simply not been added yet and the wine is therefore too acidic at the end of fermentation.

If it has not been overstretched, as in our example for the raspberries, there is usually no need to add acid. A total acidity of over 7g / l is usually not a problem during fermentation and is ideal. It depends on the end product. If it is a dry fruit wine, acid levels of 5-6g / l are perfectly acceptable. But you should not go beyond 7g / l here. The fruit wine is more durable and stable, but with higher contents. Well-buffered dessert wines with 12g / l total acidity and residual sweetness sometimes don’t taste too sour.

The result can already be seen at the beginning

Regardless of whether the fruit wine should be dry or sweet at the end, at the beginning you have to be clear about what you want to make. Elderberries or blueberries are even more substantial and are good for blending with currants if you are aiming for a dry berry wine.

Adding pear juice is always a good choice as the pear has a high extract content with a low acidity. This allows the raspberry wine from the last example to be upgraded quite well without the taste being dominated too much. On the contrary, the pear makes it vinous and rounder. We leave the 4kg raspberries, i.e. the 3L raspberry juice, and only add pear juice.

Fruit wine made from 3 parts raspberry juice and 7 parts pear juice

Raspberry juice ~ 15g / l acid, 20g / l extract

Pear juice approx. 4-7g / l acidity 30g / l extract

Acid: 3 * 15g / l + 7 * 4g / l = 73g / l: 10 parts = 7.3g / l acid

Extract: 3 * 20g / l + 7 * 30g / l = 270g / l: 10 parts = 27g / l extract

With this little movement we transform the overstretched raspberry wine from our fruit wine recipe example into a balanced, full-bodied fruit wine. We save ourselves the addition of acid and every measurement and get a good result naturally. A dilution with water or an addition of acid or even some raspberry juice or raspberry syrup would still be possible here.

If the fruit wine still tastes too sour at the end of fermentation, it may also be due to dissolved fermentation carbonic acid. A brief heating and tasting of the cooled wine provides information about whether carbon dioxide was still dissolved. This disappears through storage. In addition, residual sweet wines should be mixed with a third more sugar than necessary, because the effect of the sweetening power is reduced by storage.

Another factor is the type of acidity in the wine. Citric acid, malic acid or lactic acid. When it comes to blending, fruits that predominantly contain malic acid are often mixed with those that predominantly contain citric acid.

You should also pay attention to non-fermentable sugars such as sorbitol. If you want to produce a rich, dry fruit wine or berry wine, it can be quite interesting to use the residual sweetness of sorbitol, since this ingredient cannot be broken down further and a slight residual sweetness remains in the drink. Just enough to dampen the acidity a bit without it tasting sweet.

The same applies to fruits that are rich in extract and for fruits rich in tannin, which can provide the framework for a dark fruit wine. The same applies here: Know the ingredients of fruit and fruits and use them to your advantage. In good technical literature, most numbers are given by measurements of the ingredients of fruits. This is absolutely sufficient for most private applications.