What is each onion used for? – Differences between red onion, purple onion, and shallot

Red onion, purple onion, or shallot? Onion is the starting point for almost every savory dish, yet often only what is at home ends up in the pot. However, the flavors, spiciness, and behavior of the three types in the pan differ: what is perfect in a stew may be too harsh in a raw salad, and vice versa.

In this guide, we’ll show you how red onion, purple onion, and shallot differ, what each onion is used for, when you can substitute them for each other, and how to cut, sauté, and store them to get the most out of them.

1. Red onion, purple onion, shallot – clarifying the names

Let’s start with the most common misunderstanding. In Hungarian cuisine, red onion is not red: it is the brownish, golden-yellow-skinned onion with a whitish-yellowish interior, known in English as yellow onion or brown onion. If an English or American recipe calls for red onion, it refers to purple onion in our terms. The shallot or shallot onion is the English shallot, the French échalote.

This difference matters in reverse recipes and shopping. If a foreign salad recipe asks for "red onion" and you put in red onion, the result will be much spicier than what the recipe author envisioned.

• Red onion: brown or golden-brown skin, whitish-yellow flesh, spicy raw, sweet when cooked. In English, yellow onion or brown onion.

• Purple onion: purple skin, purple-edged layers, milder, juicier, pleasant even raw. In English, red onion.

• Shallot: smaller, elongated onion, often consisting of several "cloves", with a delicate, sweet flavor and slightly garlicky notes. In English, shallot.

All three belong to the same genus, the onion family. Red onion and purple onion are different varieties of the same species, while shallot is a close relative that develops in clusters, growing multiple smaller onions like garlic.

2. Red onion – the foundation of Hungarian cuisine

Red onion is the most versatile onion type, and it’s no coincidence that it is one of the most important ingredients in Hungarian cuisine. Raw, it has a strong, spicy, slightly pungent flavor, but it softens, becomes sweeter, and rounder when heat is applied. This duality makes it ideal for long-cooked dishes.

In our country, the Makó onion is particularly well-known, which is protected by EU origin protection. The size and spiciness of red onions available in stores can vary depending on the variety and season, but their uses are generally similar.

What to use red onion for?

• For stews, goulash, and paprika dishes.

• As a base for vegetable dishes and soups.

• For stuffed cabbage, ratatouille, and layered dishes.

• For meatballs and patties, finely chopped or grated.

• For sauces and ragouts, such as Bolognese.

• For caramelized onions and onion jam.

The secret of stews largely lies in the onion. If you slowly sauté the red onion in fat until it becomes translucent before adding the paprika and meat, the onion will almost completely break down, giving a thick, silky sauce.

Kitchen tip: Always mix the paprika into the onion off the heat. Paprika can burn and become bitter in hot fat in seconds, ruining the well-prepared onion base.

3. Purple onion – when onion plays a role raw

Purple onion is milder and juicier than red onion, making it pleasant even raw. Its flavor is less pungent, and its vibrant color makes it visually appealing on the plate. For this reason, it primarily comes to the forefront in cold dishes, salads, and when serving.

It can also be used cooked, but it’s worth noting that its color can fade to a pale, sometimes grayish-blue during cooking, and its flavor can be less pronounced than that of red onion. However, in an acidic environment, it retains and even enhances its color: it turns bright pink in lemon juice or vinegar brine.

What to use purple onion for?

• For salads, such as Greek salad, tomato, or bean salad.

• For hamburgers, sandwiches, wraps.

• For pickled, vinegar onions.

• For dips, salsas, guacamole.

• For grilling, cut into larger pieces.

• For roasted vegetables in the oven.

• For onion jam, if you want a deeper color.

Quick pickled purple onion: slice thinly, place in a jar, and cover with a mixture of equal parts vinegar and water, with a pinch of salt and a little sugar mixed in. After half an hour, you’ll have a pink, crunchy, slightly tangy side dish that will keep in the fridge for a few days.

Kitchen tip: If the raw purple onion is still too strong, soak it in cold water for 10–15 minutes, then drain thoroughly. This will reduce its spiciness while keeping it crunchy.

4. Shallot – the onion of finer flavors

Shallot is a smaller, elongated onion, often with a pinkish-purple interior, which develops not a single large bulb but several smaller, fused onions. Its flavor is finer, sweeter, and more complex than that of red onion, with a mild garlicky note. Its texture is also more delicate, almost melting into sauces when finely chopped.

In French cuisine, it plays a particularly important role: buttery sauces, wine reductions, and classic vinaigrettes often start with this onion. If you’re interested in the foundations of this cuisine, read our article on the most well-known foundations of French gastronomy.

What to use shallots for?

• For salad dressings and vinaigrettes, finely chopped.

• For buttery, wine sauces, such as white wine butter sauce.

• For risotto, where it provides a finer base than red onion.

• For steak, caramelized in butter with a little wine.

• For fish and seafood.

• Roasted whole or confit as a side dish.

Since shallots are smaller and finer, they caramelize faster and can burn more easily than red onion. Sauté them over medium or low heat, preferably in butter or a mixture of butter and oil, watching continuously.

Kitchen tip: It’s worth roasting shallots whole, in their skins, with a little oil in the oven. They become soft, sweet, almost jam-like, and pair excellently with roasted meats. You can read more about such slow, low-temperature techniques in our article on confit, blanching, and caramelizing.

5. How do purple onion and red onion differ?

This is one of the most common questions since the two onions are variations of the same species. However, the difference is quite noticeable when you taste them side by side.

• Taste: red onion is spicier and sharper raw, while purple onion is milder and sweeter.

• Juiciness: purple onion is generally juicier and crunchier, making it more pleasant raw.

• Cooking: red onion provides a deeper, more pronounced base when cooked, while purple onion’s flavor can be flatter after long cooking.

• Color: purple onion fades in color when cooked, but brightens in acidic environments.

• Storage: red onion generally stores well, while purple onion often softens sooner.

In short: if the onion will break down in the dish, choose red onion. If the onion will be visible on the plate raw, purple onion is the better choice.

6. What is the difference between shallots and red onions?

Shallots are often thought of as "small red onions", but they are not the same. A small red onion is still a red onion: spicier, wetter, and with a simpler flavor.

• Size and shape: shallots are smaller, elongated, and often split into two or three sections under the skin.

• Taste: shallots are finer, sweeter, and slightly garlicky, while red onions are more robust.

• Texture: shallot fibers are finer, almost melting away in sauces.

• Price: shallots are generally more expensive, so they are best used where their flavor can shine.

Therefore, it’s unnecessary to buy shallots for a stew, but they make a noticeable difference in a buttery sauce, vinaigrette, or risotto.

7. Can they be substituted for each other?

Yes, in most recipes, if you know what to expect. When substituting onions, it’s more about the flavor impact than the exact grams.

• Red onion instead of shallot: use less and chop very finely. About 3–4 smaller shallots correspond to a medium red onion. If using raw, a little garlic can bring the flavor closer to the original.

• Purple onion instead of red onion: works in cooked dishes, but the dish may be slightly darker in color and milder in flavor.

• Red onion instead of purple onion: in raw salads, it’s worth soaking it in cold water beforehand or pickling it briefly in vinegar water to mellow it.

• Shallot instead of red onion: you can do this anytime, but it rarely pays off in large quantities in long-cooked dishes.

What doesn’t work well: putting only purple onion in a long-cooked stew or using spicy red onion in a raw, delicate salad dressing without soaking.

8. Which onion should you choose? Quick help

The following table helps you decide which onion is suitable for what in everyday cooking.

9. How to cut onions appropriately for the dish?

The way you cut the onion influences the final result as much as the type. The smaller you chop the onion, the faster it softens and the better it blends into the dish.

• Fine dice: for stews, patties, sauces, salad dressings. Shallots should be chopped very finely.

• Half rings: for ratatouille, pan dishes, caramelized onions.

• Thin rings: for raw salads, hamburgers, pickled onions.

• Wedges: for grilling and roasted vegetables, keeping the root end intact to hold them together.

• Grating: for patties and meatballs if you don’t want chunky onion.

If you cut the onion from the root to the tip along the fibers, the pieces will hold their shape better. If you cut it crosswise into rings, they will soften and break down faster.

Kitchen tip: The reason for tearing up is that when cutting, the onion's cells are damaged, releasing volatile sulfur compounds that irritate the eyes. Using a sharp knife damages fewer cells, and pre-chilled onions in the fridge will evaporate more slowly. Leave the root end for last, as it is the strongest.

10. How to sauté onions? To translucent, golden brown, or caramelized

Recipes often simply say, "sauté the onion", but there are several stages, and each adds something different to the dish. The type of fat you sauté in also matters, which we discussed in detail in our article on the use of different oils and fats.

• Translucent sauté: at medium heat, the onion softens in a few minutes, becomes translucent, but does not brown. The base for stews, vegetable dishes, and risottos.

• Golden brown: at a slightly higher heat, sautéing longer causes the edges of the onion to brown, giving it a deeper, slightly roasted flavor. For sauces, meaty dishes, and sides.

• Caramelized: at low heat, often stirring, the onion’s own sugars slowly brown over 30–45 minutes. It becomes deep brown, sweet, and jam-like. For onion soup, hamburgers, pies, and alongside cheeses.

For caramelized onions, red onion is the most reliable choice because it loses a lot of its volume and develops a deep, rounded flavor. Shallots caramelize faster but can also burn more easily.

Kitchen tip: If the onion browns too quickly while sautéing, add a tablespoon or two of water and reduce the heat. The water will evaporate, and the onion will continue to soften evenly without burning.

11. Green onion and leek in brief

While this article focuses on the three most common onion types, two of their relatives often appear in recipes.

• Green onion: young harvested onion with green stems. Use it mainly raw for salads, on bread, in cheese spreads, or sprinkled when serving due to its mild, fresh flavor.

• Leek: long, cylindrical, mild-flavored onion. It’s suitable for soups, quiches, layered dishes, and steamed vegetables. Wash thoroughly, as soil often gets stuck between its leaves.

12. How to store onions?

Storing onions is simple, but following a few rules can help you avoid sprouting or softening prematurely.

• Cool, dry, dark place: store whole, unpeeled onions in a ventilated basket, net, or paper bag, not in plastic.

• Not in the fridge: whole red onions do not need to be kept in the fridge, as they can soften due to moisture there.

• Not next to potatoes: due to the moisture from potatoes, onions sprout and soften more easily, so store them separately.

• Cut onions: place in a tightly sealed container in the fridge and use within a few days.

• Purple onion and shallot: store them the same way as red onions. Purple onions generally last shorter.

You can read more about storing different ingredients in our article on proper food storage.

13. Frequently asked questions about onion types

Is red onion called red onion in English?

No. Red onion is called yellow onion or brown onion in English. Red onion refers to purple onion. This is one of the most common mistakes in reverse recipes.

What makes raw onion less spicy?

Slice it thinly, then soak it in cold water for 10–15 minutes, or briefly in acidic, vinegar water. Then drain thoroughly. For raw dishes, purple onion or shallot is inherently milder.

Is shallot the same as small red onion?

No. Shallot is a distinct type of onion that develops several smaller onions and has a finer, sweeter flavor. A small red onion’s flavor remains characteristic of red onion regardless.

Can I make stew with purple onion?

Yes, if necessary, but the stew will have a milder flavor and a slightly darker color. For the classic, thick, silky sauce, red onion is the more reliable choice.

Summary

Red onion, purple onion, and shallot are not the same and are not used for the same purposes. Red onion is the foundation for long-cooked, onion-based dishes like stews, vegetable dishes, and sauces. Purple onion is best when served raw and visibly on the plate, in salads, sandwiches, or pickled. Shallot is the onion for finer sauces, salad dressings, and buttery dishes.

If you remember that Hungarian red onion is the yellow onion, purple onion is the red onion, and shallot is the shallot, foreign recipes will work more easily. The rest is a matter of practice: taste them side by side and observe how your dish changes when you choose one over the other.