Broccoli Cream Soup with Hemp Seeds

Broccoli cream soup comes down to one decision: how long to cook it. Briefly cooked broccoli remains intensely green and has a fresh, slightly bitter taste. Overcooked, it turns gray and starts to smell like cabbage. This is known from the kitchen. Less obvious is what happens to sulforaphane at the same time, the compound for which broccoli has a reputation as an exceptional vegetable today. In cooked soup, it behaves differently than most recipes suggest, and we outline this below along with the studies we base it on. Additionally, you will find a step-by-step recipe here, a roasted topping of hulled hemp seeds, and numbers indicating how much protein this topping actually brings to the bowl and how well it is absorbed.

KEY INFORMATION
• Sulforaphane is formed only from glucoraphanin, with the help of myrosinase, and this enzyme loses activity above 70 degrees (Jones et al., 2010).
• In twelve volunteers, lightly heated broccoli produced about 3 times more sulforaphane than fully cooked (Rungapamestry et al., 2007).
• Hulled hemp seeds: 35.9% protein and 46.7% fat (House et al., 2010).
• Always add toasted seeds to the bowl, never to the pot.

Why do broccoli and hemp seeds complement each other well?

Because broccoli is a watery vegetable, almost fat-free and with a small amount of protein, while hulled hemp seeds provide both in high concentration. House et al. (Journal of Agricultural and Food Chemistry, 2010) measured an average of 35.9% protein and 46.7% fat in hulled seeds. A tablespoon added to the bowl changes the balance of the entire dish, not just its appearance.

There is also a practical reason. Vitamin K, which broccoli has in abundance, dissolves in fats, not in water. A soup without any fat source is a poorer carrier in this respect than a soup with oil in the base and a topping of seeds. This is not an effect that has been measured specifically in broccoli cream, but the solubility of vitamin K in fats is textbook knowledge.

Flavor-wise, the topping works as a contrast. Toasted seeds are dry, crunchy, and nutty, while the soup is smooth and moist. Without this contrast, broccoli cream can be monotonous in the mouth after the third spoonful. Toasting matters in itself: raw seeds are soft and bland, and a few minutes in a dry pan brings out a distinctly nutty aroma.

Does cooked broccoli soup retain sulforaphane?

Not in the amounts promised by most recipes. Sulforaphane is not present in raw broccoli: it is formed only when the enzyme myrosinase breaks down glucoraphanin after the plant tissue is damaged. Jones et al. (Food Chemistry, 2010) indicated that the enzyme loses activity when the inside of the floret exceeds 70 degrees.

In that study, raw broccoli was compared with broccoli steamed, microwaved, and boiled for 2 or 5 minutes, across two varieties. Steaming retained significantly more glucoraphanin, glucoerucin, and sulforaphane; boiling in water and microwaving resulted in significant losses even at these short times. Some glucosinolates also leached into the water. This loss in soup does not concern you, as you eat the water along with the rest, but the destroyed enzyme cannot be restored.

This was also tested on humans. Rungapamestry et al. (British Journal of Nutrition, 2007) provided twelve volunteers with a meal containing 150 g of broccoli heated in a microwave for 2 minutes or 5.5 minutes. The estimated amount of sulforaphane produced in the body was about three times greater for the lightly heated version. The authors note that glucoraphanin is also broken down by the gut microbiota, so sulforaphane is still produced from cooked broccoli, just less efficiently.

The conclusion for the kitchen is without drama. Eat broccoli cream for flavor and satiety, not as a source of sulforaphane. If you care about that, reach for raw broccoli or briefly steamed broccoli. We describe the compound more broadly in the post about sulforaphane from broccoli extract.

How much protein do hulled hemp seeds provide?

A tablespoon is about 10 g of seeds, which is about 3.6 g of protein and 4.7 g of fat based on the composition from House et al. Four tablespoons used in this recipe provide about 14 g of protein for the entire pot. However, protein alone is not everything, as its digestibility also matters.

The same study provides the PDCAAS score, which adjusts the amount of protein for digestibility and amino acid composition. For hulled seeds, it was 63-66%, for whole seeds 49-53%, and for the cake after oil pressing 46-51%. Lysine turned out to be the first limiting amino acid in all tested hemp products, so the frequently repeated formula about “complete hemp protein” is an oversimplification. The authors summarize more cautiously: hemp protein performs no worse than protein from some grains, nuts, and legumes.

Ingredients - what do you need?

Proportions for 4 servings. Preparation takes about 5 minutes, cooking about 20 minutes. You can buy hulled hemp seeds at a health food store; our offer does not include them, so we do not redirect you to a store for them.

• 600 g broccoli, about 1 large head including the stem
• 4 tablespoons hulled hemp seeds, about 40 g, for toasting
• 1 medium onion
• 2 cloves of garlic
• 800 ml vegetable broth
• 1 medium potato, about 150 g, optional for thickening
• 2 tablespoons olive oil
• 1 tablespoon lemon juice
• salt and pepper to taste
• optional 1 teaspoon hemp oil per serving, added cold
• optional tablespoon of nutritional yeast or grated aged cheese

Do not throw away the stems. After peeling off the woody skin, they cook just as quickly as the florets, and when blended, they give a thicker cream. Using the stem is the only change in this recipe that costs nothing. The potato is truly optional: without it, the soup comes out thinner and only broccoli is noticeable, with it, it becomes velvety but milder. Choose a well-seasoned broth, as broccoli itself contributes little in terms of salt.

How to cook broccoli cream step by step?

The whole process takes about 25 minutes, and the only moment requiring attention is the end of cooking. The broccoli should be soft enough for a fork to go into the stem without resistance, but the florets should still be green. A few minutes longer and the color turns to olive gray, which cannot be reversed.

1. Prepare the vegetables. Divide the broccoli into florets. Peel the stem with a knife or peeler and cut into 1 cm thick slices. Finely chop the onion, grate the garlic. If using, peel and dice the potato.
2. Sauté the base. In a large pot, heat 2 tablespoons of oil over medium heat. Add the onion and sauté for 4-5 minutes until soft. Add the garlic and sauté for another minute, being careful not to let it brown, as it will make the whole soup bitter.
3. Cook the broccoli. Add the broccoli and potato to the pot. Pour in 800 ml of hot broth, bring to a boil, reduce the heat, and cook covered for 12-15 minutes. Check with a fork from the tenth minute, as varieties differ in stem hardness.
4. Toast the seeds. Meanwhile, add 4 tablespoons of hulled hemp seeds to a dry pan. Toast for 3-4 minutes over medium heat, stirring constantly. Remove from heat when they are golden and smell nutty, and transfer to a plate.
5. Blend and season. Remove the pot from the heat and blend with an immersion blender for about 2 minutes until completely smooth. Add lemon juice, salt, and pepper. If the soup is too thick, thin it with broth; if too thin, simmer uncovered for a minute.
6. Serve with topping. Pour the soup into bowls. For each serving, sprinkle a tablespoon of toasted hemp seeds. If adding hemp oil, drizzle it with a teaspoon into the bowl, never into the pot. Serve immediately.

How to modify this recipe?

The broccoli base is neutral and can withstand many changes without losing its character. In the table, we have gathered four variants along with what each of them realistically changes on the plate.

Hemp flour from the second variant is a product after oil pressing, not ground whole seeds. Siano et al. (Molecules, 2018) measured 30.7% protein in such flour compared to 24.8% in seeds of the same variety, with fat dropping from 24.5% to 13.6%. Two mistakes most often ruin this soup: overcooked broccoli, which loses color, and seeds thrown into the pot instead of the bowl. We use the same topping technique in cauliflower cream with hemp seeds and curry and in miso soup with hemp seeds.

Frequently Asked Questions

How to maintain the green color of broccoli soup?

Cook for no longer than 15 minutes and blend immediately after removing from heat. Overcooking breaks down chlorophyll and turns the green into olive gray, which cannot be reversed. Lemon juice added just before serving enhances the freshness of the flavor.

Does cooked broccoli soup retain sulforaphane?

In small amounts. Myrosinase, the enzyme needed to produce sulforaphane, loses activity above 70 degrees (Jones et al., 2010). In twelve volunteers, broccoli heated for 2 minutes produced about three times more sulforaphane than heated for 5.5 minutes (Rungapamestry et al., 2007).

Is broccoli cream soup with hemp seeds vegan?

Yes, in the basic version. The density comes from broccoli, the stem, and the optional potato, not cream. Hemp seeds provide fat and protein without animal ingredients. The version with nutritional yeast also remains vegan; the one with aged cheese does not.

How to thicken broccoli cream without cream?

The simplest way is to cook one potato together with the broccoli. Another way is to add 2 tablespoons of hemp flour at the end of blending: the flour from the cake has about 30.7% protein compared to 24.8% in the seeds themselves (Siano et al., 2018) and thickens without starch and gluten.

When to add hemp seeds to broccoli soup?

Only to the bowl, just before serving. Toast them beforehand in a dry pan for 3-4 minutes. In hot soup, they soften in a few seconds and lose the nutty flavor for which they are toasted. The entire value of the topping lies in the contrast of textures.

This article is for informational and educational purposes and does not replace consultation with a doctor. If you are pregnant, breastfeeding, taking medications, or have chronic conditions, consult the use of supplements or herbs with a specialist.

Author: Michał Waluk · Published: 2026-06-15 · Updated: 2026-08-16