Why it works: Potato and onion are a kitchen classic. They rank in the top 3% of all ingredient pairs, and cooks put them together in 9,023 recipes. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓
Vegetable Soup
Ingredients
Directions
Make the vegetable base
Put two potatoes, one onion, and a piece of bread into a quart of water; boil down to a pint.
Add a little chopped celery or parsley and salt.
Cover, remove from the fire, and allow to cool.
Thicken and season
Mix a tablespoonful or a tablespoonful and a half of arrowroot with a little cold water until it makes a paste.
Boil a pint of water, stir in the arrowroot, and boil for a few minutes.
Sweeten with white sugar.
Add brandy or wine if necessary.
Add half or all milk instead of water.
Add a little lemon or orange peel before boiling.
Prepare the tapioca
Cover two tablespoonfuls of tapioca with a teacupful or more of cold water, and soak for two or three hours, or overnight.
Put the soaked tapioca into a pint of boiling water, and boil until it is clear and of the desired consistency.
Add sugar, nutmeg, or wine as required.
Nutrition, whole recipe (rough)
Counts 3 of 4 ingredients. The other 1 aren't in our nutrition table and add nothing above, so the real totals are higher.
What these numbers assume: 3 portions
| Ingredient | Portion assumed | kcal |
|---|---|---|
| Flour | 1 cup (125g) all-purpose | 455 |
| Potato | 1 medium (173g) baked | 161 |
| Onion | 1 medium (110g) | 44 |
| Water | not in our table | 0 |
One typical portion per ingredient; the recipe's quantities are not counted. A rough guide only, not for medical or dietary planning.
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. See the original page.
Photo for illustrative purposes only · Contact us to use it
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.
-
Potato + oniontop 3% of all pairsSmell alikemoderateCooked together9,023 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
-
Bread + oniontop 15% of all pairsSmell alikemoderateCooked together8,676 recipes
Shared aroma: 2,4-decadienal (seaweed).
-
Bread + potatotop 15% of all pairsSmell alikemoderateCooked together434 recipes
Shared aroma: 2-acetyl-1-pyrroline (popcorn, roasted).
Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs
What each ingredient does
- Potatoes
- Break down during boiling to give the soup body and a thicker, smooth texture.
- Onion
- Adds savoury depth and aroma as it softens in the boiling water.
- Arrowroot (in the method)
- Starch that thickens the liquid into a clear, glossy consistency when boiled.
- Tapioca
- Starch that swells on soaking and boiling, thickening the soup and turning it clear.
The step that matters
Boiling the arrowroot. Starch must be fully mixed into cold water before adding it to hot liquid, otherwise it clumps. Boiling then gelatinises the starch so the soup thickens evenly.
Swap the potato
How well each one fits the dish's main ingredients (bread, onion):
- Leekfits about as well
- Chivefits about as well
- Potatothe original
- Tomatofits about as well
Fit is the average pairing score against bread, onion. 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.
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