Why it works: Mustard and onion match in chemistry and in kitchens. They rank in the top 6% of all ingredient pairs, and cooks put them together in 9,259 recipes. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓
Onion Pickle
Ingredients
Directions
Prepare the onions
Peel the onions.
For nine consecutive mornings, scald the onions with fresh salt water, pouring off the old water each time.
On the 10th day, drain the onions and pack them in jars.
Make and pour the dressing
Make a dressing of one pound ground mustard, one cup oil, one pound sugar, and enough vinegar to cover well.
Bring the dressing to a boil.
Pour the boiling dressing over the onions in the jars.
Do not fill the jars too full of onions; ensure plenty of dressing remains.
Nutrition, whole recipe (rough)
What these numbers assume: 4 portions
| Ingredient | Portion assumed | kcal |
|---|---|---|
| Olive Oil | 1 tbsp (14g) | 119 |
| Sugar | 1 tbsp (12.5g) granulated | 49 |
| Onion | 1 medium (110g) | 44 |
| Mustard | 1 tsp (5g) yellow | 3 |
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.
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.
-
Mustard + oniontop 6% of all pairsSmell alikestrongCooked together9,259 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
-
Mustard + sugartop 19% of all pairsSmell alikemoderateCooked together8,424 recipes
Shared aroma: guaiacol (smoky, sweet).
-
Sugar + oniontop 36% of all pairsSmell alikelowCooked together15,747 recipes
Shared aroma: guaiacol (smoky, sweet).
Sugar and onion barely smell alike, yet cooks put them together in 15,747 recipes: they work on texture and structure more than aroma.
Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs
What each ingredient does
- White onions
- Form the bulk of the pickle, becoming crisp-tender as they are scalded and then steeped in dressing.
- Ground mustard
- Adds sharp, pungent flavor that gives the dressing its characteristic bite.
- Sugar
- Balances the sharpness of the vinegar and mustard with sweetness.
- Oil
- Adds fat to the dressing, carrying flavor and giving a smoother mouthfeel.
- Vinegar (in the method)
- Provides acidity that preserves the onions and sharpens the flavor of the dressing.
The step that matters
Do not overfill the jars with onions. Onions need enough hot dressing surrounding them to be fully covered and flavored. If the jars are packed too tightly, dressing cannot circulate, leaving some onions unseasoned and reducing the acidic coverage that helps keep the pickle stable.
Swap the onion
How well each one fits the dish's main ingredients (mustard, sugar):
- Horseradishfits better
- Lettucefits better
- Broccolifits better
- Onionthe original
Fit is the average pairing score against mustard, sugar. 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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