Some recipes call for smoked meats, resulting in a distinctively smoky borscht, while others use poultry or mutton stock.
Fasting varieties are typically made with fish stock to avoid the use of meat, while purely vegetarian recipes often substitute forest mushroom broth for the stock.
It is added to borscht shortly before the soup is done, as prolonged boiling would cause the tart flavor to dissipate.
As the traditional method of making borscht with beet sour often requires planning at least several days ahead, many recipes for quicker borscht replace the beet sour with fresh beetroot juice, while the sour taste is imparted by other ingredients, such as vinegar, lemon juice or citric acid, tomatoes, tart apples, dry red wine, dill pickle juice, sauerkraut juice, or a fermented rye flour and water mixture.
Meat stock is usually cooked for about two hours, whereas bone stock takes four to six hours to prepare.
Borscht derives from an ancient soup originally cooked from pickled stems, leaves and umbels of common hogweed (Heracleum sphondylium), a herbaceous plant growing in damp meadows, which lent the dish its Slavic name.
Sugar, salt and lemon juice may be also added to balance the flavor.
After about 2–5 days (or 2–3 weeks without the bread), the deep red, sweet and sour liquid may be strained and is ready to use.
With time, it evolved into a diverse array of tart soups, among which the beet-based red borscht has become the most popular.
It is typically made by combining meat or bone stock with sautéed vegetables, which – as well as beetroots – usually include cabbage, carrots, onions, potatoes and tomatoes.