What is acidity in juices? Juice research

Stomach acidity is an important indicator of the state of a person’s internal environment and his overall health. In various parts of the gastrointestinal tract, acidity changes depending on the function of the area, and changes in this indicator in one direction or another can lead to the development of a whole galaxy of various diseases. Determining the acidity of the stomach helps in diagnosing and monitoring gastrointestinal diseases, and everyone should be able to recognize the symptoms accompanying acid-base changes in the stomach.

Normally, the composition of gastric juice includes hydrochloric acid and bicarbonates, which have an alkaline reaction, that is, in different sections, the processes of synthesis of acid and bases take place alternately, and sometimes simultaneously. For the mucous membranes that line the entire gastrointestinal tract, both extremes are dangerous because they represent an aggressive environment. But together they neutralize each other, restraining the damaging effect.

Gradually passing through these sections, the contents of the stomach physiologically move along the digestive tract, breaking down into molecules that the body is able to absorb. Most enzymes are secreted in an inactive form, so that the stomach wall is not digested along with food, and they become active at a certain acidity for each section.

Stomach acidity normally varies for each section and depends on the time of day and food intake. In the stomach cavity on an empty stomach, the acidity is in the range of 1.5-2 pH, and approaching the transition to the duodenum, the pH shifts to the neutral and even slightly alkaline side (up to 7.4). In the epithelial layer, the acidity should be neutral.

Only if the acidity matches will digestion be effective and the gastrointestinal mucosa will remain intact.

Why do you need to maintain a certain acidity?

The oral cavity is inhabited by a huge number of microorganisms, which, with adequate functioning of the immune system, do not pose a danger to a healthy person. Mixing with food, they enter the stomach, which is the main factor of protection against infection precisely due to the acidic reaction of gastric juice. Hydrochloric acid neutralizes most bacteria that enter the stomach, preventing them from entering the intestines, where they can be absorbed into the systemic bloodstream.

The first stage of the breakdown of complex molecules occurs in the stomach under the action of its own enzyme systems. The stomach wall is rich in glands that produce various enzymes, in particular pepsinogen.

Pepsinogen is an inactive form of the enzyme pepsin, which breaks down proteins. Under the influence of hydrochloric acid, inactive pepsinogen is converted into active pepsin. Hydrochloric acid is also involved in the breakdown of proteins, having an independent proteolytic effect.

Like any other acid, HCl has a mild irritant effect. By stimulating motility and irritating receptors, hydrochloric acid becomes a trigger for the movement of food from the stomach to the duodenum.

Why determine acidity?

Measuring acidity in the stomach is prescribed for an accurate diagnosis; changes in this indicator indicate developing pathology of the gastrointestinal tract.

Depending on which direction the acid-base state has shifted, you can find the cause that caused the disease. Only by normalizing acidity can effective therapy be achieved.

Methods for determining acidity

The least accurate and approximate information in the hospital is provided by probeless method, based on identifying different staining of urine using ion exchange resins. “Acidotest” has become more widespread in this line of products. The kit includes several tablets with:

• dye;
• ion exchange resins;
• stimulator of gastric juice secretion.

Resins are inert for the body and are not absorbed into the gastrointestinal tract, and, therefore, cannot appear in the urine, like the dye, which is in a strong complex with them. But the dye is easily replaced by hydrogen ions coming from hydrochloric acid. Depending on how many ions from the hydrochloric acid have displaced the dye, the urine will be colored differently. The kit comes with a color scale, which is used to judge a particular condition.

Probing of the stomach will tell you more accurately about the state of acidity: gastric contents are sucked out, the acidity of which is measured in the laboratory. This method is not physiological, since the mixing of liquids from different sections that have different acidity occurs. The result is an average figure with little reliability.

The process of probing the stomach

During the It is also possible to determine the acidity of the stomach by irrigating the mucous membrane through a flexible endoscope with a special acidity indicator. The method is visual and also not very accurate.

Intragastric pH testing is considered the gold standard and the most informative way to determine acidity. This method not only gives an accurate pH number, but also reflects a complete picture of the distribution of acid in the stomach in different parts of the gastrointestinal tract or even at different times of the day.

How to suspect an acidity disorder at home?

You can determine the acidity of the stomach using a simple test with litmus paper, which can be purchased at the pharmacy. The test strip should be placed on the tongue for a few seconds.

It is important to conduct the study either 2 hours after a meal or an hour before a meal. Remember that you should not drink juices and carbonated drinks on this day, they can distort the result; limit yourself to clean drinking water. It is best to repeat the experiment on different days and then look at the average result.

Litmus paper is a simple indicator for changing the pH of the environment.

Changes in paper color will indicate the acid-base state of gastric juice:

• red (or pink) color – acidic environment;
• purple color is a neutral environment.

Another method is based on the psychosomatic reaction of the body. It is enough to mentally imagine the taste and smell of lemon and listen to your feelings. Lack of secretion or increased secretion of saliva are signs of a change in the environment in the stomach.

Obviously, at home it is impossible to accurately determine “your” acidity in the stomach. But anyone can suspect a violation; just monitor your feelings throughout the day.

Increased acidity

Most often, an increase in pH in the stomach accompanies the development of so-called acid-dependent diseases. These include hyperacid duodenitis and gastritis, peptic ulcers of the duodenum and stomach, as well as GERD (gastroesophageal reflux disease).

• pain that occurs after eating (1-2 hours later);
• sour belching;
• burning and heaviness in the abdomen (heartburn);
• nausea (in rare cases, vomiting);
• tendency to constipation.

Low acidity

Low acidity of gastric juice is a common pathology that is practically asymptomatic until atrophic gastritis develops. Low secretion of hydrochloric acid leads to a weakening of the antimicrobial barrier, which leads to frequent intestinal infections and weakened gastric and intestinal motility.

Symptom complex characteristic of this condition:

• bad breath;
• lack of appetite;
• weakness, chronic fatigue;
• tendency to constipation or diarrhea;
• anemia;
• tendency to allergic reactions;
• flatulence (increased formation of gases in the gastrointestinal tract);
• recurrent stomach upsets.

How to normalize acidity?

With increased levels of acidity in the stomach, drugs from the anticholinergic group, such as atropine and platyphylline, have shown their effectiveness. The aggressiveness of gastric contents is also reduced by:

• antisecretory drugs (ranitidine, omeprazole);
• antacids (Renny, Gastal).

Among the folk remedies, potato and aloe juice, propolis tincture and natural honey have proven themselves. Carrot juice and warm milk can reduce gastric secretion and, accordingly, acidity. In addition, carrot juice reduces abdominal pain, having a weak analgesic effect.

It is much more difficult to increase stomach acidity. Traditional medicine can also help: wormwood, calamus or peppermint. Herbal mixtures of chamomile, St. John's wort and herbs (wormwood) should be brewed in a thermos and taken half a glass half an hour before meals.

Drug therapy is prescribed only after a therapeutic diet has been prescribed and has had its effect. Replacement therapy includes hydrochloric acid preparations (acidin-pepsin) or drugs that stimulate the production of gastric juice. They cannot be prescribed independently and without constant supervision from a specialist.

Eating with high acidity levels

A therapeutic diet for high acidity levels is prescribed taking into account the degree of damage to the mucous membrane and the stage of the process.

During an exacerbation, the first thing you need to do is reduce any irritation of the inflamed stomach: chemical, thermal or mechanical. Food should not be too hot or cold; spicy, salty and especially sour foods should be completely excluded from the diet. The patient should chew food well and eat small portions, but often. All products are steamed or boiled. An hour before meals, the patient is recommended to drink bicarbonate mineral water.

During the period of remission, it is allowed to add carbohydrates (wheat and rye bread, cookies, crackers), lean meat, and soups prepared with vegetable broth to the diet. As before, it is better to stick to the steamed “diet” and avoid eating spicy, salty or sour foods. Mucosal-enveloping agents (natural jelly or oatmeal infusions) have a beneficial effect.

This patient is given a health education conversation about the dangers of alcohol and smoking, which stimulate the secretion of the gastric glands, which is unacceptable in a patient with a high level of acidity.

Eating with low acidity levels

Common mistakes in the treatment of low acidity levels are stimulation of secretion and attempts to artificially increase acidity. This should not be done under any circumstances, since the mucous membrane is in a weakened state; you should not load the stomach even more. First of all, it is necessary to prescribe a gentle diet with easily digestible foods.

As in the case of a high level of acidity, the dish of choice will be various porridges (oatmeal, buckwheat), rice, mashed potatoes. Products should be of a soft, uniform consistency and not hot in temperature. The patient can prepare vegetable soups, steamed lean meat and fish, and even flour.
From the moment the symptoms subside, you can begin stimulating the secretion of gastric juice. Sour fruit and tomato juices and marinades help with this. Vitamins will be useful for improving general condition and as stimulators of mucosal healing.

VII. JUICE RESEARCH

To prepare wort you need to know how much juice is contained in the resulting juice. acids (acidity juice) and Sahara (sugar content juice). This is necessary to know in order to prepare wine of the desired quality, since in most cases the juices of fruits and berries contain excess acids and insufficient amounts of sugars.

In home winemaking, especially if a small amount of wine is being prepared, you can use Table 2 when determining the composition of the juice. If the winemaker is preparing wine on a small-scale or industrial scale, or if they want to make wine of very high quality, then it is better to conduct a more detailed study of the juice. (For example, I use a table).

Juice acidity determined by the amount of alkali spent to neutralize the acid contained in the juice, which is based on the properties of acids to combine with alkalis.

Fruit and berry juices contain various acids: tartaric, malic, citric, succinic, etc. As a rule, malic and citric acids predominate, unlike grapes, where tartaric acid occupies a dominant position (although other acids are also present, but in much smaller quantities).

When determining the acidity of juice, the total acidity is calculated in terms of the acid predominant in the juice. For grape juice and wine - in terms of tartaric acid, for fruit and berry juice, as a rule, in terms of malic and less often citric acid (depending on which of them predominates in a given type of fruit and berries).

The acidity of the juice is determined by adding an alkali solution of a certain concentration (titration solution) to it. The titer is the amount of alkali in 1 ml of solution, and titration is the determination of acidity using a titration solution. The result of the reaction when adding alkali to the juice is looked at using an indicator - litmus paper. When determining the amount of acid in juice or wine, use a titrated solution of sodium hydroxide.

To determine acidity, the winemaker must have: a pipette; glass tube with marked divisions (burette); glass glass or porcelain cup; glass rod, titration solution, litmus indicator (litmus paper that turns blue with alkali and red with acid).

Pipette- a glass tube with divisions marked on it must hold at least 10 ml of liquid.

Burette- glass tube with marked divisions for each 1 ml of volume up to 25-50 ml.

Titration solution. It is a solution of dry sodium hydroxide in an amount of 5.97 g, dissolved in 1 liter of distilled water. You will need approximately 0.3 liters. The previously prepared solution can be stored in a glass bottle with a chemical-resistant rubber stopper.

Determination of acid content.

The essence of the method is to add a titration solution to a certain volume of juice until the resulting mixture turns the litmus paper blue, which means that the alkali neutralizes all the acid in the juice. Knowing the initial volume of juice and the volume of alkali titration solution consumed, and that 1 ml of alkali neutralizes 0.1% acid, you can easily determine the acidity of the juice.

Let's take a closer look at the following example. Let's say apple juice is available. Place a clean, dry burette on the table vertically, then carefully pour 10 ml of juice into it. Pour this strictly measured amount of juice into a glass glass. If the existing juice is brightly colored (blackcurrant, etc.), then the measured amount of juice can be diluted by pouring distilled water using a pipette (pour in the contents of the pipette 3-5 times) so that the juice becomes less colored. Mix the resulting mixture of juice and water with a glass rod. This dilution of the juice will not affect the acidity indicator, since when diluted, only the volume of the mixture will change, and the amount of acid will not change, because exactly 10 ml of juice was taken.

Then add the titration solution from a pipette into a glass with juice in measured portions, after each addition, mix the juice with a glass rod, and apply droplets from the glass rod to litmus paper. The red color of the litmus means that not all the acid has yet been neutralized and therefore we add a new portion of the alkali titration solution. We will do this until the red color of the entire litmus paper changes to blue, which will happen when all the acid is neutralized with an alkali. Let us use 21 ml of an alkaline titration solution to neutralize 10 ml of apple juice, then this means that 1 liter of juice contains 21 grams. malic acid, or 2.1% acid.

To determine the acidity of fermenting juice or wort, a measured amount of juice (wort) must be heated to a boil to remove carbon dioxide, which was formed during the fermentation process and can distort these determinations.

Determining the amount of sugar in juice.

The total amount of sugar in juice can be determined by the specific gravity of the juice, which is based on the relationship between the density of the juice and its sugar content. Specific gravity is determined by weighing a measured amount of juice on an accurate scale or using a hydrometer. Before determining the amount of sugar, the juice must be filtered through a paper filter. The juice temperature should be 19-20°C.

The specific gravity of juice is determined as follows: using a clean, dry 10 ml pipette, measure 10-100 ml of filtered juice into a clean, dry glass, which must be weighed before filling with juice. Then use precise scales to determine the weight of the glass of juice. We divide the weight of the measured juice by the weight of water of the same volume, the resulting division result will be the desired specific gravity of the juice. To calculate the percentage of sugar in juice, subtract 1 from the specific gravity value and divide the remaining difference by 5. The resulting figure will indicate the percentage of sugar.

For example, 100 ml of juice weighs 104 g, and 100 ml of water weighs 100 g. The specific gravity of the juice will be: 104 : 100 = 1.040. We subtract one from the specific gravity: 1.040 - 1.00 = 0.040, or simply 40 (to simplify calculations). We divide this difference by 5 and get the percentage of sugar in the juice, i.e. 40 : 5 = 8 or 8%.

Using a hydrometer, determining the percentage of sugar is easier and faster. The filtered juice is brought to a temperature of 20°C and poured into a tall narrow vessel. It is necessary to pour so that no foam forms. A clean, dry hydrometer is carefully lowered vertically into the juice, preventing it from diving. If the hydrometer body, located above the surface of the juice, is wetted with juice, then the hydrometer readings will be incorrect, since the device will become heavier. Carefully lower the hydrometer into the juice being tested, holding the top part with two fingers. If the hydrometer is immersed, the body should be rinsed with clean water and wiped dry, and the measurement process should be repeated again. The hydrometer readings should be taken so that the eye is level with the surface of the juice.

If the temperature of the juice differs from 20°C, then a temperature correction is made to the hydrometer reading. If the temperature is above 20°C, then to the hydrometer reading you must add the value obtained by multiplying the difference in temperature degrees by 0.0002. For example, at 25°C the hydrometer reading is 1.053, and the actual weight will be: 1.053 + (5 x 0.0002) = 1.054. And, conversely, when the juice temperature is below 20°C, the temperature difference multiplied by 0.0002 must be subtracted from the hydrometer reading.

For example, the hydrometer reading at a juice temperature of 14°C is 1.041. Then the value is: 1.041 - (6 x 0.0002) = 1.0398.

After making a temperature correction, the sugar content in it is determined by the specific gravity of the juice.

In addition to sugars, juice also contains extractive substances, the content of which varies in different juices. These extractive substances affect the accuracy of the results of determining the sugar content of juice, allowing a deviation within 1. Therefore, when studying low extractive juices (for example, apple juice), 1 must be added to the sugar content indicator by specific gravity. When calculating, use the formula:

C = (U: 5) + 1, where C is the sugar content in the juice in % or in g. per 100 ml of juice; Y is an indicator of specific gravity in which leading ones and zeros are excluded. For example, specific gravity is 1.041, then Y = 41, then C = (U : 5) + 1 = 9,2%.

When determining the amount of sugar in juices of medium extract (red and white currants, raspberries, strawberries, etc.), use the formula:
C= (U: 5).

All these studies of juice must be carried out to make quality wine. In home winemaking, especially if a small amount of wine is being prepared, you can use

Hydrochloric acid occupies a significant place in the composition of gastric juice. It is its main component. Acid helps ensure that food is processed properly and ensures its gradual movement from the stomach through the so-called pyloric sphincter (pylorus of the stomach) into the duodenum.

It also performs other functions that are no less important for the human body:

• Promotes the processing and denaturation of protein in the gastric cavity. Thanks to this, its subsequent splitting is greatly facilitated.
• Promotes the activation of pepsinogens, which are converted into pepsins.
• Forms an acidic environment, without which the action of enzymes contained in gastric juice is impossible.
• Causes the process of pancreatic secretion.
• Promotes the antibacterial effect of gastric juice.

It is almost impossible for a modern person to protect himself from nervous tension, to do without stress, minor or causing huge problems in life. The accelerated course of life and its rapid rhythm often do not leave time for observing the principles of proper and regular nutrition. Such overloads are reflected in the level of acidity of gastric juice, changing it in one direction or another. Then, without changing anything in your lifestyle, it is almost impossible to protect yourself from gastrointestinal diseases. Reduced or increased stomach acidity signals that a chronic disease may have developed - gastritis.

Determination of acidity

You can diagnose and determine the specific level of acidity in a medical facility. Modern research methods provide fairly accurate results. But you can determine whether acidity is low or high at home.

How to preliminarily determine what its trend is (increase or decrease) without leaving home? To do this, there is no need to spend money on expensive reagents, swallow a probe and take tests. At first, it is enough to take a closer look at your own body, pay attention to symptoms that were not there before. After all, if acidity fluctuates upward or downward, this cannot but affect your well-being: it also changes.

Increased acidity: determine it yourself

An increase in acidity is a pathology that negatively affects the general condition of the body. Since the walls of the gastrointestinal tract are irritated by excess acid, a person develops such visible symptoms:

• A burning sensation in the pharynx and esophagus that occurs very sharply - heartburn. The reason for its appearance is the release of excess hydrochloric acid into the esophagus. Heartburn can occur at any time, for no apparent reason. But most often it is provoked by sour juices and foods containing a lot of spices and herbs. For example, these are tomato, plum, peach juices, smoked meats, mustard, ketchup. With increased acidity, heartburn will certainly appear after eating lemons, grapefruits, kiwis, and green apples.

  Alkaline mineral water, sunflower seeds, and a baking soda solution help to quickly get rid of these unpleasant sensations.

• Copper and sour taste in mouth. Occurs when seeing and smelling sour foods. Even the very thought of lemons, pickled or pickled cucumbers, sauerkraut, apples causes a significant amount of saliva to appear in the mouth.
• Belching may occur regardless of the type of food. But as usual, like heartburn, it occurs when fried, fatty and spicy foods predominate in the diet. Sweet juices, jam, ice cream, cakes and cookies also cause this unpleasant phenomenon.
• Aching, dull and nagging pain in the stomach. It intensifies when a feeling of hunger appears. It often occurs in the morning. These are the so-called “hunger pains”. They almost always subside when a fresh portion of food enters the stomach.
• Heaviness in the stomach and bloating after every snack, even a minor one.
• Violation of the process of defecation: constipation or diarrhea. Both symptoms can cause reluctance to eat. After all, sometimes you just have to eat - your stomach immediately chokes, and further frequent trips to the toilet are guaranteed.
• Taking anti-inflammatory drugs causes nausea or stomach pain. These symptoms appear immediately after taking medications.

In addition to the problems listed above, the following signs of increased acidity may also occur:

• Headaches after eating fatty, fried or smoked foods.
• Decreased or complete loss of appetite.
• Mood decreases, loss of strength and apathy appear.
• Discomfort in the stomach cannot but cause irritability.
• Attacks of nausea and vomiting. They come almost at the same hour when eating is finished, or after a short period of time. But this symptom appears much less frequently than all the previous ones.
• Problems with the stomach and digestion coat the tongue with a whitish-gray and yellow coating.

If none of the described symptoms are present, then the acidity of the stomach is within normal limits. But the feeling of at least a few of them should be a reason to contact a gastroenterologist.

How to determine yourself whether acidity is low

If the acidity is low, there is a desire to eat something sour: cabbage, cucumber, even lemon. Black rye bread, spices and seasonings, ketchup, apple and grapefruit juices stimulate the appetite.

A decrease in hydrochloric acid content is just as much a deviation from the norm as an increase. Solyanka, which is contained in gastric juice, neutralizes food entering the esophagus from pathogenic microorganisms and harmful bacteria. When the acidity decreases, that is, the specific gravity of hydrochloric acid in the juice drops, the disinfection process fails. As a result, various unwanted bacteria penetrate into the stomach, the number of which increases.

A process of inflammation of the mucous membrane occurs, and a person develops symptoms, the most characteristic of which are:

• Belching with the smell of rotten eggs or with a rotten taste. It provokes the appearance of bad breath, which is very unpleasant and has a putrid odor.
• Present feeling of bloating, rumbling. Fermentation processes occur in the gastrointestinal tract. They cause pain from accumulated gases and flatulence.
• Burning in the throat (heartburn).
• Feeling of heaviness in the hypochondrium.
• Dumb pain in the navel area after each snack or a short time after it.
• Feeling as if something is bursting from the inside.
• Stool disorders are another manifestation of low acidity. An insufficient amount of acid in gastric juice significantly reduces its antibacterial effect. Microorganisms that enter the human intestine unhindered change its microflora and upset the balance. A person either suffers from constipation or cannot get rid of diarrhea. Difficulty defecating is caused by intestinal motor disorders, which, in turn, are explained by insufficient acidity.

Its reduced level leads to incomplete absorption of proteins. As a result, decay products accumulate in the stomach, which poison the entire body. Immunity decreases, and the door opens for the development of pathological processes. First of all, the appearance of various mycoses is possible: fungal infections cover the mucous membranes of the oral cavity, skin, and nails. The body becomes more susceptible to viruses and various infections.

There is insufficient absorption of vitamins and minerals contained in food. And, as a consequence, it is easy to notice that:

• The skin on your hands and face becomes dry.
• Nails grow slowly, break and peel.
• Hair becomes thinner, brittle and dry. Their growth also slows down.
• The appearance of acne and dilation of blood vessels on the nose and cheeks are other visible signs of a decrease in acidity.

If acidity has been low for a long time, then the person feels:

• General weakness.
• Weight loss.
• Lethargy and loss of strength.
• Tendency to a sedentary lifestyle and hypotension.

If you suspect the presence of low acidity, you need to carefully examine your feces. If they contain undigested food remains or pieces of food, the suspicions are justified.

Symptoms of low or high acidity do not appear all together. Typically, only one or two signs are present.

If such features appear and there is a slight disturbance in your health, you can, of course, try to adjust the acidity of the stomach yourself. To do this, first of all you need to adjust your diet.

But if the situation does not improve and the discomfort increases, you should seek help from a doctor. Special examination methods will help to accurately determine the acidity of the stomach and the causes of possible deviations. The sooner you get diagnosed and treated, the fewer health problems you will have in the future.

Most fruit juices contain too much acid and not enough sugar. Without stabilizing the must, the wine turns out to be very sour and not strong enough. Only some grape and apple juices do not require correction; in other cases, the intervention of the winemaker cannot be avoided. There are methods that allow you to normalize acidity and sugar content, minimally affecting the organoleptic properties of wine.

You can determine the initial acidity of the juice using a special device - a “pH meter” or using reference tables for the content of acids and sugars in fruits. It is advisable to use data from your region. Average data are shown in the tables.

Wines with 4-6 grams of acid per liter are considered balanced. During fermentation, the concentration drops, so the initial acidity of the wort is made higher - 6-15 grams per liter.

Sometimes, for example, in pear juice, it is necessary to increase the acidity of the wort. The easiest way to do this is by adding the required amount of citric acid (juice). The juice of one lemon contains 4-5 grams of acid.

Methods for reducing the acidity of wine

Attention! You need to reduce acidity before or during fermentation (with the exception of cold settling), working with must, not finished wine.

1. Dilution with water. The most common method used by almost all home winemakers. One drawback is that the extract of the wine decreases, as a result the drink loses some of its aroma and taste.

Water reduces the acidity of the juice by half. It is important to consider the added sugar. After dissolving, 1 kg of sugar increases the volume of the wort by 0.6 liters, reducing acidity in the same proportion as water.

Let's say there is juice with an acidity of 18 grams per liter and a sugar content of 8%. If we want to reduce the acid content to 6 g/l, we need to dilute it three times (18:6=3), that is, add 2 liters of water per 1 liter of juice. But the acid concentration also drops due to the added sugar, so its volume must be subtracted from the calculated amount of water.

1 gram of fermented sugar (natural and introduced) gives 0.6% alcohol in wine. To obtain a wine with an alcohol content of 12%, a total of 200 g/l of sugar is required. In the example, the volume of wort is planned to be 3 liters; to obtain the given strength, 600 grams of sugar will be required. At the same time, 80 grams are in the juice itself, which means that during fermentation you need to add another 520 grams (600-80). This sugar will occupy a volume of 0.312 liters (520×0.6). We reduce the amount of water by this volume (2-0.312 = 1.688 l).

Therefore, to prepare wine with a strength of 12% and an acidity of 0.6%, you need to add 520 grams of sugar and 1.688 liters of water to the juice with the initially specified parameters. At first, the calculations seem complicated, but in fact, if you understand the essence, everything is simple.

2. Blending of juices. The idea is to mix sour juice in certain proportions with other non-acidic juice, leveling out the overall acidity of the wort. It is advisable to mix juices of the same fruits, but of different varieties. For example, grape with grape (red with red), apple with apple, etc. If the fruits are different, in most cases the wine will not taste good.

Unlike adding water, mixing juices does not reduce the richness of taste; this is the optimal method to reduce acidity, but is rarely used in home winemaking, since it is difficult to find material suitable for blending.

3. Adding acid suppressants. Adding substances to the wort that neutralize acid. These can be special powder chemicals (used according to instructions) or folk remedies: chalk, plaster and eggshells.

First, the shell is washed, the film covering the inside of the egg is removed, and then crumbled into small pieces. Chalk and gypsum can be placed whole or pre-crushed. Part of the wine material is poured into a separate container and mixed with a damper. To neutralize 1 gram of acid, 1 gram of chalk or eggshell is required. When sediment has formed, the low-acidity juice is added to the main wort (without sediment). The disadvantage of this method is that after neutralization an unpleasant odor may appear.

4. Cold. When the temperature drops to 2-4°C, acid salts precipitate. The method is used for both must and finished wine; with its help you can reduce acidity by 1-1.5 g/l, which is very little. Cold can only correct wines with a slight excess of acid.

5. Boiling. High temperature reduces the acidity of wine, but this method has a number of disadvantages, including: coagulation of proteins (extractivity decreases), the appearance of a “cooked” taste, loss of aroma, and death of yeast. Because of this, boiling is almost never used.

To determine the acidity of a wine as accurately as possible, you will have to do a little magic. Armed with a burette, pipette, litmus paper and a special titration liquid, you will get a fairly accurate result. In addition, after carrying out simple manipulations, you will know exactly how much sugar you will need next time to get a drink with the acid you need.

To make good wine, it is important that the juice has a certain acidity. Sufficiently acidic juice ferments better, resulting in a reduced risk of mold and the development of harmful bacteria. The acidity of wine is considered normal in the range from 6 to 10%.

The basis for determining the acidity of juice is the ability of acids to combine with alkalis. Therefore, the acidity of the juice can be determined by the amount of alkali that was required to neutralize the acid.

The process of determining the acidity of juice is called titration (from “titr” - the amount of alkali in 1 ml of solution) and consists of adding an alkali solution of a certain concentration to the juice - a titrated solution.

As a rule, sodium hydroxide solution is used as this agent. The completion of the reaction is determined by litmus paper, which turns red in acid and turns blue in alkali.

How to determine the acidity of wine must at home

Before determining the acidity of wine at home, prepare the following equipment:

• 10 ml pipette;
• burette – a glass tube with a glass stopcock with a volume of up to 50 ml, on which divisions corresponding to a volume of 0.1 ml are applied; for convenience, the burette should be installed vertically (best using a tripod);
• porcelain cup;
• glass rod;
• titration liquid, that is, 5.97 g of dry sodium hydroxide, dissolved in 1 liter of distilled water, 0.25 liter volume (store in a glass bottle with a ground stopper);
• litmus paper.

The process for determining the acidity of wine must is as follows. The titration liquid is poured into a clean, dry burette. Then open the tap to release the air from the burette. This must be done, otherwise the result will be incorrect. The upper liquid level is set at the zero division of the burette. After this, the pipette is filled with juice to zero division (10 ml) and poured into a cup.

Since fruit and berry juices are highly colored, they are first diluted with distilled water (at the rate of 20–50 ml per 10 ml of juice) and stirred well. If it is not available, you can use ordinary water, but boiled 4-6 times. The fact that the juice is diluted with water does not affect its acidity at all. The same amount of acid remains in the diluted juice, it just becomes less colored, which makes it much easier to obtain the result.

After this, place a cup with diluted juice under the burette, carefully open the tap and release 1 drop of the alkaline solution. The contents of the cup are thoroughly mixed with a glass rod and the juice is applied to litmus paper with it. If it remains red, it means the acid has not yet been neutralized. Add 1 more drop of alkaline solution into the cup and check the contents again with litmus paper, and so on until the litmus paper turns blue, that is, until all the acid combines with the alkali. It is known that 1 ml of alkali corresponds to 0.1% acid in the juice.

In addition, the wine must contain acid - about 6-7 g per 1 liter. You can reduce acidity by adding water to fruit juice before fermentation.

The acidity of wine is determined by the titratable acid content in grams per liter of wine (ppm) and can range from 2.5 to 9 g/l.

It should be remembered that the acidity of light wines can be 5.5–7 g/l of acid per liter, table wines – from 7 to 9 g/l, dessert wines – 9-11 g/l.