Kvass, also known as podpiwek, grew out of the everyday experience of the ancient Slavs. Already in the 10th century, they consciously used the fermentation of rye breadto obtain a drink with an amber color, a light effervescent structure and a clearly refreshing character. In those times, access to clean water was very limited, so the acid served as a safe, microbiologically stable substitute – mildly acidic, naturally saturated with carbon dioxide and at the same time nutritious.

Sources from the Jagiellonian era note, that the Polish nobility also drank kvass, treating it as a drink to “soothe the stomach” after heavy, multi-course feasts. In villages, however, it functioned as a “village orangeade”. It was most often consumed during summer field work to quickly quench thirst.

In the 19th century, kvass recipes they were closely guarded by the orders, that improved the fermentation processensuring the appropriate proportions of bread, water and natural yeast cultures. During this period, kvass became a common drink throughout the entire region of Eastern Europe – from Poland to the areas of today’s Ukraine and Russia. In the interwar period, it was treated as a natural isotonic – workers drank it in mines and industrial plants because it effectively quenched thirst and replenished minerals faster than water. In some regions, raisins were added to the yeast, which rose and fell during fermentation – a simple but accurate indicator of yeast activity.

Nowadays, we observe a clear return of kvass, which is fueled growing interest in traditional and fermented food. In eastern countries, it is sold both in bottles and street barrels, and is also used as a base for cold soups, including the classic okroshka. In Poland, it is back in the spotlight as a regional product – local factories recreate historical recipes, emphasizing their connection with craft heritage and local identity.

Natural kvass is produced during the slow fermentation of rye bread, during which it develops lactic acid, phenolic compounds and live cultures of bacteria and yeast. A study conducted in 2024 by the University of Rzeszów (Comparison of the Antioxidant and Sensorial Properties of Kvass Produced from Mountain Rye Bread with the Addition of Selected Plant Raw Materials) showed that enriching the acid with plant additives, e.g. mint, berries or herbssignificantly increases its antioxidant potential, i.e. the ability to neutralize free radicals responsible for oxidative stress, often accompanying autoimmune diseases. However, this does not replace treatment or supplementation recommended for hypothyroidism or Hashimoto’s disease.

In 2025 SNDT Women’s University (India) published an analysis of the kvass fermentation process (“Fermentation process and quality evaluation of traditional kvass beverage“, confirming that the traditionally prepared drink contains numerous strains of lactic acid bacteria. These are microorganisms that support the intestinal microbiome, improving the regularity of bowel movements and relieving digestive discomfort. The authors point out that natural acid is unlike industrial versions retains active bacterial cultures as well as organic acidssupporting metabolism and stabilizing glucose levels after meals. The drink has a low energy value, about 25-30 kcal per 100 mlso it can be used as an alternative to sweetened carbonated drinks.

The health-promoting properties of kvass also result from the presence of B vitaminsnaturally formed during fermentation. They support the nervous system and metabolic processes. The acid also contains valuable minerals, including: magnesium, potassium and small amounts of zinchelping to maintain electrolyte balance.

Kvass is recommended for people struggling with it with a feeling of heaviness, flatulence or imbalanced intestinal microflora. Natural fermentation “organizes” the functioning of the digestive system, and the mild glycemic profile makes the drink popular among those who want to maintain a stable glucose level after meals. Low caloric value combined with the presence of organic acids promotes a longer feeling of satiety, thanks to this, acid can be an ally of people who are reducing body weight and trying to limit snacking. For those who are trying to reduce the amount of caffeine, it is a good substitute because it gently stimulates and does not burden the stomach. They should consume it too physically active peoplethat need natural support in the regeneration of the body.

However, there are situations in which it is worth being careful. Kvass, as a drink resulting from fermentation, contains trace amounts of alcohol, therefore it is not recommended for pregnant or breastfeeding women. People allergic to gluten or yeast should read labels carefully, because traditional kvass is prepared on the basis of rye bread. AT people with reflux its acidity may intensify the burning sensation in the esophagus, while SIBO It is advisable to consult a dietitian before the drink is included in the daily menu. In the case of a gluten-free diet, it is possible to prepare kvass on buckwheat or certified oat bread.

The quality of the product itself is also important – it emphasizes that in some fermented drinks available on the market microplastics may be present. For this reason, homemade versions or products from local manufacturers who use traditional methods and natural raw materials may be a better choice. The optimal portion of acid is 100-200 ml per day – it is best to consume it between meals or after a heavy dish. People with a sensitive stomach should avoid drinking acid on an empty stomach.

Homemade kvass does not need marketing or artificial additives, because its strength lies in the simplicity of the ingredients and the slow rhythm of fermentation. Unlike store versions, often pasteurized and devoid of live bacteria cultures, home-prepared kvass retains the full set of probiotic bacteria.

Ingredients:

• 500-1000 g of whole grain rye bread (preferably home-made sourdough bread),
• 4-5 liters of clean water,
• 100-200 g of sugar (or less if you prefer a less sweet taste),
• 10 g of fresh yeast,
• a handful of raisins (natural fermentation catalyst.

Preparation:

1. Cut the bread into pieces and pour hot, but not boiling water. Set aside for 24 hours. After a few hours, the liquid becomes a deep amber color, and after a day of rest it will become a full-fledged base for fermentation.
2. Strain the liquid, add sugar and dissolved yeast. Cover and leave in a warm place for another 24 hours.
3. When you see bubbles and light foam, pour the liquid into bottles and add raisins. Fruits contain yeast and sugars, which intensify the process of saturating the drink with carbon dioxide in a closed space. It is worth using bottles made of thicker glass or with a secure closure.
4. Cool and wait 2-3 days. Coolness slows down fermentation while allowing the flavors to stabilize. After two days, the drink is light, fresh and slightly effervescent; after three – drier, with a deeper flavor profile.

Real kvass should be slightly sour, refreshing and have a vivid amber color. Unlike many commercial “acids”, this homemade one contains live cultures of bacteria and enzymes that support intestinal health. You can drink it alone or use it as a base for cold soups.

Sources: Terazgotuje.pl, ResearchGate

Kvass, also known as podpiwek, grew out of the everyday experience of the ancient Slavs. Already in the 10th century, they consciously used the fermentation of rye breadto obtain a drink with an amber color, a light effervescent structure and a clearly refreshing character. In those times, access to clean water was very limited, so the acid served as a safe, microbiologically stable substitute – mildly acidic, naturally saturated with carbon dioxide and at the same time nutritious.

Sources from the Jagiellonian era note, that the Polish nobility also drank kvass, treating it as a drink to “soothe the stomach” after heavy, multi-course feasts. In villages, however, it functioned as a “village orangeade”. It was most often consumed during summer field work to quickly quench thirst.

In the 19th century, kvass recipes they were closely guarded by the orders, that improved the fermentation processensuring the appropriate proportions of bread, water and natural yeast cultures. During this period, kvass became a common drink throughout the entire region of Eastern Europe – from Poland to the areas of today’s Ukraine and Russia. In the interwar period, it was treated as a natural isotonic – workers drank it in mines and industrial plants because it effectively quenched thirst and replenished minerals faster than water. In some regions, raisins were added to the yeast, which rose and fell during fermentation – a simple but accurate indicator of yeast activity.

Nowadays, we observe a clear return of kvass, which is fueled growing interest in traditional and fermented food. In eastern countries, it is sold both in bottles and street barrels, and is also used as a base for cold soups, including the classic okroshka. In Poland, it is back in the spotlight as a regional product – local factories recreate historical recipes, emphasizing their connection with craft heritage and local identity.

Natural kvass is produced during the slow fermentation of rye bread, during which it develops lactic acid, phenolic compounds and live cultures of bacteria and yeast. A study conducted in 2024 by the University of Rzeszów (Comparison of the Antioxidant and Sensorial Properties of Kvass Produced from Mountain Rye Bread with the Addition of Selected Plant Raw Materials) showed that enriching the acid with plant additives, e.g. mint, berries or herbssignificantly increases its antioxidant potential, i.e. the ability to neutralize free radicals responsible for oxidative stress, often accompanying autoimmune diseases. However, this does not replace treatment or supplementation recommended for hypothyroidism or Hashimoto’s disease.

In 2025 SNDT Women’s University (India) published an analysis of the kvass fermentation process (“Fermentation process and quality evaluation of traditional kvass beverage“, confirming that the traditionally prepared drink contains numerous strains of lactic acid bacteria. These are microorganisms that support the intestinal microbiome, improving the regularity of bowel movements and relieving digestive discomfort. The authors point out that natural acid is unlike industrial versions retains active bacterial cultures as well as organic acidssupporting metabolism and stabilizing glucose levels after meals. The drink has a low energy value, about 25-30 kcal per 100 mlso it can be used as an alternative to sweetened carbonated drinks.

The health-promoting properties of kvass also result from the presence of B vitaminsnaturally formed during fermentation. They support the nervous system and metabolic processes. The acid also contains valuable minerals, including: magnesium, potassium and small amounts of zinchelping to maintain electrolyte balance.

Kvass is recommended for people struggling with it with a feeling of heaviness, flatulence or imbalanced intestinal microflora. Natural fermentation “organizes” the functioning of the digestive system, and the mild glycemic profile makes the drink popular among those who want to maintain a stable glucose level after meals. Low caloric value combined with the presence of organic acids promotes a longer feeling of satiety, thanks to this, acid can be an ally of people who are reducing body weight and trying to limit snacking. For those who are trying to reduce the amount of caffeine, it is a good substitute because it gently stimulates and does not burden the stomach. They should consume it too physically active peoplethat need natural support in the regeneration of the body.

However, there are situations in which it is worth being careful. Kvass, as a drink resulting from fermentation, contains trace amounts of alcohol, therefore it is not recommended for pregnant or breastfeeding women. People allergic to gluten or yeast should read labels carefully, because traditional kvass is prepared on the basis of rye bread. AT people with reflux its acidity may intensify the burning sensation in the esophagus, while SIBO It is advisable to consult a dietitian before the drink is included in the daily menu. In the case of a gluten-free diet, it is possible to prepare kvass on buckwheat or certified oat bread.

The quality of the product itself is also important – it emphasizes that in some fermented drinks available on the market microplastics may be present. For this reason, home-made versions or products from local producers who use traditional methods and natural raw materials may be a better choice. The optimal portion of acid is 100-200 ml per day – it is best to consume it between meals or after a heavy dish. People with a sensitive stomach should avoid drinking acid on an empty stomach.

Homemade kvass does not need marketing or artificial additives, because its strength lies in the simplicity of the ingredients and the slow rhythm of fermentation. Unlike store versions, often pasteurized and devoid of live bacteria cultures, home-prepared kvass retains the full set of probiotic bacteria.

Ingredients:

• 500-1000 g of whole grain rye bread (preferably home-made sourdough bread),
• 4-5 liters of clean water,
• 100-200 g of sugar (or less if you prefer a less sweet taste),
• 10 g of fresh yeast,
• a handful of raisins (natural fermentation catalyst.

Preparation:

1. Cut the bread into pieces and pour hot, but not boiling water. Set aside for 24 hours. After a few hours, the liquid becomes a deep amber color, and after a day of rest it will become a full-fledged base for fermentation.
2. Strain the liquid, add sugar and dissolved yeast. Cover and leave in a warm place for another 24 hours.
3. When you see bubbles and light foam, pour the liquid into bottles and add raisins. Fruits contain yeast and sugars, which intensify the process of saturating the drink with carbon dioxide in a closed space. It is worth using bottles made of thicker glass or with a secure closure.
4. Cool and wait 2-3 days. Coolness slows down fermentation while allowing the flavors to stabilize. After two days, the drink is light, fresh and slightly effervescent; after three – drier, with a deeper flavor profile.

Real kvass should be slightly sour, refreshing and have a vivid amber color. Unlike many commercial “acids”, this homemade one contains live cultures of bacteria and enzymes that support intestinal health. You can drink it alone or use it as a base for cold soups.

Sources: Terazgotuje.pl, ResearchGate