Ingredients
The ferment
- 300 gcoarse wheat bran
- 100 gcornmeal
- 2.5 litreswarm water
- 1 sliceof stale rye bread, or 100 ml of a previous borș, as starter
- 2 sprigslovage, if you have it
- 1 tspsalt
Equipment
- a large glass or ceramic crock, never metal
- a wooden spoon
Directions
- Mix the bran and cornmeal in the crock and pour over the warm water — hand-hot, around 35°C (95°F), not hotter.
- Stir in the starter: either a slice of stale rye bread or, far better, a cupful of borș from a previous batch. Add the lovage and salt.
- Cover with a cloth and leave somewhere warm, around 25°C (77°F). Stir once a day with a wooden spoon.
- Use wood or plastic, never metal. The ferment becomes genuinely acidic and a metal spoon or crock taints it with a distinct metallic edge that carries straight into the soup.
- After three to five days it will smell sharply sour and slightly yeasty, and taste distinctly acidic. That sourness is the entire product.
- Strain the liquid off through a fine sieve or muslin into bottles. This clear sour liquid is the borș.
- Keep it refrigerated, where it holds a fortnight and goes on sharpening.
- To use, add it to a soup at the end of cooking and boil for two or three minutes — Moldovan and Romanian cooks always boil it before serving, which settles the flavour and drives off the raw yeasty note.
- Keep a cupful of the strained liquid to start the next batch.
Technique
- Never metal. This is the one rule of a borș crock.
- Boil it briefly in the soup rather than stirring it in raw at the table.
- It is a souring agent, not a stock. It brings acid to zeamă and ciorbă the way lemon or vinegar would, but with a rounder, more savoury sourness.
Substitutions
- Lemon juice or vinegar as an emergency substitute in a soup, though neither has the same depth.
- Bottled borș, sold in Romanian and Moldovan shops, which is exactly this.
- Rye flour in place of some of the bran, which starts it faster.
Variations
- Ciorbă is the general name for any soup soured this way.
- Some households add a handful of cherry twigs, which is said to help the ferment along.
History
Kept in a crock in Moldovan kitchens and refreshed with wheat bran, the country’s defining souring agent.
Frequently asked questions
What is Bors acru?
Bors acru is a fermented & pickled from Moldova: sour bran ferment stirred into zeamă and other soups. Kept in a crock in Moldovan kitchens and refreshed with wheat bran, the country’s defining souring agent.
How long does Bors acru take to make?
Bors acru takes 20 min plus 3 to 5 days souring of preparation and 10 min of cooking. The recipe makes makes about 2 litres of borș. It is rated easy to make.
What can I substitute in Bors acru?
Yes, within limits. Lemon juice or vinegar as an emergency substitute in a soup, though neither has the same depth. Bottled borș, sold in Romanian and Moldovan shops, which is exactly this. Rye flour in place of some of the bran, which starts it faster.
What is the most important thing to get right in Bors acru?
Use wood or plastic, never metal. The ferment becomes genuinely acidic and a metal spoon or crock taints it with a distinct metallic edge that carries straight into the soup.
