3tbspwhite wine vinegar or cider vinegaror to taste
⅔tbspcoarse sea salt plus plenty of pepper
1tbspbutteror vegan spread
Rinse the porcini mushrooms (if using) under cold water and rub briefly with your fingertips to remove any grit. Place all the ingredients (apart from the butter) in a large pot, cover and bring to the boil. Lower the heat and simmer for 50 minutes.
Remove from the heat and add the butter, adjust the seasoning, remove the vegetables and serve (only the liquid) with porcini dumplings.
If you make the Polish porcini dumplings to go with this barszcz reserve the water from cooking the mushrooms and add it into this soup. One or two quarters of a cup will suffice. If you choose this method you won't need to add any mushrooms to the borscht.
Flavour: You can make this soup as sharp and tangy as you like so use the vinegar, pickled beetroot brine, soy sauce and seasoning according to your preference.
Although soy sauce is not a traditional ingredient it is a good idea to use it in this recipe. Soy sauce complements the beetroot, adding complexity and more depth to the overall flavour.