Walnut catsup is a dark, savory British condiment dating back to the 1700s. It was a staple in Georgian and Regency-era kitchens — the kind of thing Mrs. Bennet would have had in her pantry. It tastes nothing like modern ketchup: think Worcestershire sauce meets soy sauce, with deep umami and warm spice.

Recipe Overview

A beautifully preserved Victorian kitchen with cast-iron range
A beautifully preserved Victorian kitchen with cast-iron rangecc by-sa 3.0
  • Prep time: 30 minutes
  • Ferment/brine time: 8–10 days
  • Cook time: 45 minutes
  • Yield: About 2 cups

Ingredients

A classic dark condiment bottle of British brown sauce
A classic dark condiment bottle of British brown saucecc by-sa 2.0
  • 50 green (unripe) walnuts, picked before the shell hardens (typically late June/early July)
  • 1/2 cup coarse salt
  • 2 cups malt vinegar (or red wine vinegar)
  • 4 anchovy fillets, minced
  • 1 tablespoon whole black peppercorns
  • 6 whole cloves
  • 1/2 teaspoon ground mace
  • 1 small piece fresh ginger (about 1 inch), sliced
  • 2 shallots, quartered

Instructions

  1. Wear gloves — green walnuts stain everything brown. Pierce each walnut several times with a fork or skewer.
  2. Place the walnuts in a large crock or glass jar. Cover with the coarse salt, tossing to coat. Cover loosely and leave at room temperature for 8–10 days, stirring once daily. The walnuts will turn black and release a dark liquid.
  3. After brining, crush the walnuts in the crock with a wooden spoon or potato masher to extract all the liquid.
  4. Strain the walnut liquid through cheesecloth into a saucepan, pressing hard on the solids. Discard the walnut pulp.
  5. Add the vinegar, minced anchovies, peppercorns, cloves, mace, ginger, and shallots to the walnut liquid.
  6. Bring to a boil, then reduce heat and simmer uncovered for 45 minutes until reduced by about one-third.
  7. Strain through a fine-mesh sieve lined with cheesecloth. Discard the solids.
  8. Pour into sterilized bottles and seal. Store in a cool, dark place. The flavor improves over the first month and keeps for a year or longer.

Tips

  • The walnuts must be green and soft enough that a needle passes through easily. Once the inner shell has formed, they cannot be used for catsup.
  • Use this like you would Worcestershire or soy sauce — a few dashes in stews, gravies, and meat pies.
  • Historical recipes sometimes add horseradish or cayenne. Experiment to taste after the initial simmer.

Explore more traditional and modern recipes on our catsup recipes page.