Name: Barley Soup
Ingredients: 2 lbs shin of beef; ½ lb pearl barley; 4 onions; 4 good-sized potatoes; 1 bunch of parsley; pepper to taste; coarse sea salt to taste; 4 quarts water

Why it works: Parsley and pepper match in chemistry and in kitchens. They rank in the top 2% of all ingredient pairs, and cooks put them together in 34,122 recipes. Both carry 4'-methylacetophenone, which smells bitter almond. The science ↓

Barley Soup

Ingredients

Directions

Prepare

Cut the beef into pieces and break the bones.
Prepare the vegetables by peeling and chopping them.

Simmer and serve

In a large pot, combine the beef, bones, vegetables, barley, parsley, and seasoning with the water.
Simmer for several hours until the flavors meld.
Remove the bones before serving.
Serve the soup with fried croutons.

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.

Parsley + peppertop 2% of all pairs

Smell alikestrong

Cooked together34,122 recipes

Shared aroma: 4'-methylacetophenone (bitter almond).
Onion + potatotop 3% of all pairs

Smell alikemoderate

Cooked together9,023 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Potato + parsleytop 5% of all pairs

Smell alikemoderate

Cooked together2,855 recipes

Shared aroma: 4'-methylacetophenone (bitter almond).
Barley + potatotop 5% of all pairs

Smell alikestrong

Cooked together165 recipes

Shared aroma: beta-damascenone (apple, rose).
Beef + oniontop 7% of all pairs

Smell alikemoderate

Cooked together17,092 recipes

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

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

What each ingredient does

Shin of beef: Gives the soup its meaty body and rich flavor as it simmers.
Pearl barley: Thickens the broth slightly and adds a chewy texture.
Potatoes: Break down partly during simmering, adding body and starch to the broth.
Onions: Build savory sweetness and aroma as they cook into the broth.

Swap the parsley

How well each one fits the dish's main ingredients (beef, barley, onion, potato, pepper):

Garlicfits about as well
Thymefits about as well
Celeryfits about as well
Parsleythe original

Fit is the average pairing score against beef, barley, onion, potato, pepper. 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.