Mustard Powder

Food · Pantry & Condiment · Food, Typed Supps

Ground mustard seed. It only turns hot when mixed with cold water, and only for a while.

Stage by stage

Mixing and intake (Myrosinase reaction): Water lets the enzyme meet its substrate, generating allyl isothiocyanate within minutes.
Nasal passages (Volatile pungency): The compound is volatile, so the heat is felt in the sinuses and clears quickly.
Stomach (Trivial quantity): A teaspoon is around two grams, so nothing nutritionally meaningful arrives.
Circulation (No systemic contribution): The seed's selenium and folate are real per 100g but negligible at condiment doses.

Time to effect

Minutes: Pungency develops over about ten minutes after mixing with cold water and fades over the following hours.

Allergens

Contains: Mustard. Derived from what this food is, not from a product label.

Eating patterns

Fits: Vegan, Vegetarian, Pescatarian, Halal, Kosher, Gluten-free. Depends on the product: Low-FODMAP.

Satiety

Not scored: the satiety index is measured on 240 kcal servings, and nobody eats a 240 kcal serving of this. The question does not apply rather than the answer being unknown.

Cost band

Mid — roughly £5 per kg, as a band midpoint rather than a price.

Key nutrients

Nutrition per 100g

Calories: 547
Protein: 29.4g
Carbohydrate: 17.2g
of which sugars: 5g
Fat: 39.5g
of which saturated: 2g
Fibre: 5g
Sodium: 3mg

Food vs. supplement

Nobody supplements with mustard, and nobody should. If selenium is the goal, the per-100g figure is misleading — two Brazil nuts do in a mouthful what a jar of mustard powder could not do across a year of normal use.

Kitchen tip

Mix the powder with cold water and leave it ten minutes before adding vinegar, salt or anything hot. That window is when the enzyme does its work. Add acid straight away, or use hot liquid, and you get a mild yellow paste instead — which is exactly how mild table mustards are made deliberately.

Common myth

"Mustard powder is a nutrient-dense seed food." In reality: Per 100g it genuinely is, being ground whole seed. But it is used a teaspoon at a time, and at that dose its selenium, folate and magnesium contribute almost nothing. Its real value is flavour without salt.

In the glossary

Enzyme