Skip to main content
Sauce

Eye-opener Catsup

A catsup made from green tomatoes, onions, vinegar, and spices.

From an old cookbook · modernised transcription
From a historical cookbook (Internet Archive) · 4 ingredients
Jump to recipe ↓

Why it works: Tomato and onion are a kitchen classic. They rank in the top 8% of all ingredient pairs, and cooks put them together in 20,633 recipes. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓

Eye-opener Catsup

Ingredients

Directions

Cook the base

  1. Chop the green tomatoes and onions.

  2. Cover with vinegar and boil until tender.

  3. Rub the mixture through a sieve.

Season and finish

  1. Add spices and more vinegar to taste.

  2. Return to the kettle and boil until it reaches the consistency of catsup.

Recipe from a historical cookbook (Internet Archive).

Transcribed from a scanned cookbook and modernised for today's kitchens. Where the book gave no heat or time, or said "a moderate oven", the temperatures and times here may be modern equivalents rather than the book's own figures.

Explore the science

The flavor team

The pairs that carry this dish. Each one is judged two ways: how much their aromas overlap, and how often cooks already put them together.

  1. Tomato + oniontop 8% of all pairs
    Smell alikemoderate
    Cooked together20,633 recipes

    Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).

  2. Onion + vinegartop 14% of all pairs
    Smell alikemoderate
    Cooked together18,226 recipes

    Shared aroma: acetic acid (sour, vinegar).

  3. Tomato + vinegartop 16% of all pairs
    Smell alikemoderate
    Cooked together5,063 recipes

    Shared aroma: beta-damascenone (apple, rose).

Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs

What each ingredient does

Green tomatoes
Provide the main body and bulk, breaking down into a thick pulp when cooked and sieved.
Onions
Add savory depth and a mild sweetness as they soften during boiling.
Vinegar
Adds sharp acidity that brightens the flavor and helps soften the tomatoes and onions.

The step that matters

Boil down to the consistency of catsup. Thickening happens as water evaporates during boiling. Stopping too early leaves the ketchup thin, while boiling too long can scorch the bottom and make it overly stiff once cooled.

Swap the tomato

How well each one fits the dish's main ingredients (onion, vinegar):

  1. Mustardfits better
  2. Cucumberfits better
  3. Radishfits better
  4. Tomatothe original

Fit is the average pairing score against onion, vinegar. Candidates are from the same food group and used in at least 100 recipes.

“What each ingredient does” and “The step that matters” were written by Claude from this recipe’s own method and reviewed in samples by CompKitchen.

You might also like

Wine Sauce (for stewed fruit)Wine Sauce (for stewed fruit)186 recipesCaper SauceCaper Sauce180 recipesBrown SauceBrown Sauce141 recipesDutch SauceDutch Sauce74 recipes