Mustard Seeds in the Kitchen: Popping, Tempering and Making Your Own Mustard

Mustard seeds are tiny but mighty. They add a nutty crunch when fried, a sharp heat when crushed with liquid, and a tang to pickles and dressings. They are widely used in Indian, European and American cooking. Understanding the three main types makes them much easier to use.

Yellow, brown and black

Yellow mustard seeds (sometimes called white) are the mildest and are used in American yellow mustard and pickling spice. Brown mustard seeds are stronger and common in Indian cooking and Dijon-style mustards. Black seeds are the most pungent, although they are harder to find. If a recipe does not specify, brown is the safest choice for tempering, while yellow is best for mild mustard.

Popping seeds in oil

This technique is called tempering, or tadka. Heat 2 tablespoons of oil in a small pan over medium heat. Add 1 teaspoon of brown mustard seeds and cover the pan. They will begin to pop within 30 seconds. Once the popping slows, take the pan off the heat and pour the oil and seeds over cooked lentils, rice, yoghurt, coleslaw or steamed vegetables.

The seeds lose their harshness and turn nutty. If they pop wildly out of the pan, turn down the heat and use a lid. If they turn grey or smell burnt, discard and begin again.

How the heat works

Whole mustard seeds have very little heat until they are crushed and mixed with a liquid. That reaction creates the characteristic sharp flavour. Cold water makes the strongest heat, whereas hot water, vinegar or heat from cooking tames it. This is why mustard made with vinegar is milder than mustard mixed with water.

Quick homemade mustard

You can make a basic mustard in a few minutes, but it needs a few days to mellow:

1. Mix 1/4 cup yellow mustard seeds and 2 tablespoons brown mustard seeds with 1/2 cup of cold water. Soak overnight.

2. Blend with 1/4 cup vinegar, 1 teaspoon salt and 1 teaspoon honey until mostly smooth.

3. Spoon into a clean jar and refrigerate for two to three days. The flavour will mellow from harsh to pleasant.

It keeps in the fridge for several weeks. Try adding herbs, horseradish or a splash of white wine.

Using whole seeds

Stir whole yellow mustard seeds into pickle brines, potato salads and sauerkraut. Toss toasted brown seeds into roasted cabbage or cauliflower. Add a teaspoon to slaw dressing. Pickled mustard seeds, sometimes called poor man's caviar, are made by simmering seeds in vinegar and sugar until plump.

Mustard seeds love coconut, curry leaves, lentils, potatoes, cabbage, beets, pork, sausage and ham. In South Indian cooking, they are nearly always combined with curry leaves, cumin and dried chilli.

Keep seeds in a sealed container away from light and heat. Whole seeds keep for years, which is one of their best features. Ground mustard powder loses its sharpness within a year or so.

Who should check first

Mustard is a recognised food allergen in many countries, and reactions can be serious. If you or your guests are allergic, avoid it and read labels on sauces and dressings carefully. People taking blood thinners or those with thyroid conditions, kidney disease or who are pregnant should ask a doctor before eating very large amounts. Everyday cooking amounts are small.

This article is general information, not medical advice.