Borș: Romania's Traditional Souring Agent for Soups Explained

If you have eaten a Romanian soup, especially a ciorbă, you have probably tasted borș. This cloudy, sour liquid is a defining ingredient in many traditional recipes, adding a tang that lemon or vinegar cannot quite replicate. But what exactly is borș, and how do you use it?

What is borș?

Borș is a fermented liquid made from wheat bran, sometimes with the addition of cornmeal or rye bread. It has a distinctly sour, slightly yeasty flavour and a pale, opaque appearance. Unlike Russian borscht, which is a beetroot soup, Romanian borș is a souring agent added to soups and stews. It plays a similar role to vinegar or lemon juice but brings a deeper, more complex acidity.

The name borș is also used colloquially to refer to sour soups in general, but in most Romanian kitchens, the liquid itself is the key. It is particularly essential in ciorbă de legume, ciorbă de fasole, and ciorbă de perișoare, where it balances the richness of the broth.

How is borș made?

Traditionally, borș is made at home with just a few ingredients. Wheat bran is mixed with warm water in a large jar or crock, often with a slice of cornbread or a spoonful of cornmeal to kick-start fermentation. The mixture is left in a warm place for three to five days, stirred occasionally. As it ferments, it develops a pleasantly sour taste and a slightly effervescent quality. Once ready, the liquid is strained and stored in bottles.

Commercially produced borș is widely available in Romanian shops, usually in glass or plastic bottles. It is typically pasteurised or preserved with salt, which alters the flavour slightly but remains convenient. Homemade borș has a fresher, more vibrant sourness, and many cooks insist on making their own.

Using borș in the kitchen

The most common use for borș is in ciorbă, the hearty sour soups that are a staple of Romanian meals. It is typically added near the end of cooking, after the vegetables and meat are tender. A ladleful or two is enough to brighten the entire pot. Because borș is already fermented, it does not need to cook for long; boiling it too much can diminish its delicate acidity.

Beyond soups, borș can be used to deglaze pans for sauces or to add a sour note to bean stews. Some people even drink a small glass of borș chilled as a refreshing, probiotic-rich beverage, though this is more common in rural areas. If you cannot find borș, a mixture of lemon juice and a splash of water can work in a pinch, but the result will be less nuanced.

Regional differences

Borș is especially beloved in the southern and eastern regions of Romania, such as Muntenia and Moldova, where it is the default souring agent for ciorbă. In Transylvania, cooks more often reach for vinegar or lemon, a reflection of Austro-Hungarian culinary influences. In some parts of the country, the word borș refers to the soup itself rather than the souring liquid, so menus may list 'borș de sfeclă' (beetroot soup) or 'borș de pui' (chicken soup) without implying the use of fermented wheat bran.

Tips for cooks

If you buy borș from a shop, check the label for natural fermentation and minimal additives. It should smell pleasantly sour, not sharp or chemical. Store it in the refrigerator after opening, and use it within a few weeks. When adding borș to a hot soup, taste as you go—its strength can vary between brands and batches. Start with a small amount and build up until the soup has a balanced tang.

Making your own borș is a simple way to connect with Romanian culinary tradition. All you need is wheat bran, water, a jar, and a little patience. The result will transform your soups and give you a true taste of Romania's home kitchens.