Tomato Soup

Tomato Soup

Tomato soup is a small test case in understanding cooking: it has barely five ingredients, and yet most homemade versions come out too sour or flat. Both problems stem from the same source — a fresh tomato is an acidic, watery vegetable, and a good soup requires reversing both.

The solution is not sugar but roasting. Tomatoes roasted at 200°C (392°F) lose water, concentrate sugars and caramelize at the edges, and all of this lowers the perceived acidity long before you reach for the sugar. In this recipe only a single teaspoon of sugar remains, and its job is to fine-tune, not to rescue.

Prep time: 15 minutes · Roasting and cooking time: 55 minutes · Total: about an hour and a quarter · Yield: 6 servings · Difficulty: easy

Lycopene: the component that cooking actually improves

Tomatoes contain lycopene, a carotenoid responsible for the red color and considered one of the most studied antioxidants in nutrition. Unlike vitamin C, which is destroyed by heat, lycopene actually becomes more available to the body with cooking: the heat breaks down the plant cell wall and releases it from the matrix that traps it.

Lycopene is fat-soluble, so its absorption rises even further in the presence of olive oil — which is why tomato soup with oil is, nutritionally, a better way to eat tomatoes than a salad. More on the tomato page and the polyphenols page.

Ingredients (for 6 servings)

For roasting:

• 1.5 kg ripe tomatoes — preferably cherry or plum (date) tomatoes, which are the sweetest — halved
• 1 large onion, thickly sliced
• 4-5 whole garlic cloves in their skins
• 3 tablespoons olive oil
• 1/2 teaspoon salt, black pepper

For the soup:

• 1 tablespoon tomato paste
• 600 ml vegetable stock or water
• 1 teaspoon sugar — only if needed, after tasting
• A bunch of fresh basil
• 100 ml heavy cream 38% — optional
• Salt, black pepper, a pinch of chili flakes

Choosing ingredients and substitutes

Plum, cherry or ripe regular tomatoes all work for roasting; you don’t need a special variety. If you have no fresh basil, add a teaspoon of dried basil while the soup cooks, for a milder taste. The cream is optional; you can also use 100 ml of 15% cooking cream instead of 38%, added with gentle heating.

Method

1. Preheat the oven to 200°C (392°F). Arrange the tomatoes cut side up, together with the onion and garlic, on a lined baking tray. Drizzle with olive oil, salt and pepper.
2. Roast for 35-40 minutes, until the edges blacken in spots and the tomatoes have shrunk. This is the step that decides it — tomatoes that have only softened won’t give the sweetness. Don’t overcrowd the tray: crowded tomatoes steam instead of roasting.
3. Transfer to a pot. Squeeze the garlic out of its skin, and put the entire contents of the tray into a pot, including the juices that collected — they are concentrated in flavor.
4. Cook. Add the tomato paste and stir for a minute over medium heat, then pour in the stock. Bring to a gentle boil and cook for 15 minutes.
5. Blend. Puree with an immersion blender. If you want a completely smooth soup, pass it through a coarse sieve to remove skins and seeds — a step you don’t have to take, but it changes the texture a lot.
6. Balance. Taste. If the acidity is still sharp, add a teaspoon of sugar, and only if it needs more — another small pinch. Sugar masks acidity, it doesn’t balance it; if the soup is both sour and flat, the problem is salt.
7. Finish. Add cream if you like and heat for 2 minutes without boiling. Add the basil, torn by hand, off the heat — cooking destroys its aroma within a minute.

Nutrition facts and calorie estimate

The recommended serving is a bowl of about 300 ml, a sixth of the pot, in the version with cream.

The kilo and a half of tomatoes come to only about 45 calories per serving. Everything else is the oil and the cream — so here too, as in mushroom soup, the vegetable is not the calorie factor. The difference is that the three tablespoons of olive oil here are not “excess”: without them lycopene absorption drops significantly, which makes them some of the most worthwhile spoonfuls in the kitchen.

The weakness of this soup, as with most pureed soups, is protein — 3 grams per bowl. It is an excellent starter and a poor meal, unless you add something to it.

What you add in the bowl:

Variations and tips

• From canned tomatoes, out of season: 2 cans of drained whole tomatoes (about 800 grams) are better than pale fresh tomatoes in winter. Roast them on a tray for 20 minutes using the same method. Canned tomatoes are picked ripe and usually contain more lycopene.
• A vegan and lighter version: instead of cream — 100 ml of light coconut milk (about 25 calories per serving) or 30 grams of ground almonds blended in with the soup, which add body and also 1.5 grams of protein per serving.
• Turn it into a meal: a can of white beans blended in adds about 45 calories and 4 grams of protein per serving, and makes the cream unnecessary.
• Cold tomato soup: thin with a little cold water and chill — the base is very close to Spanish gazpacho, but with roasted rather than raw tomatoes.
• Making ahead: 4 days in the fridge and 3 months in the freezer — always without the cream, which tends to separate when thawed.

Summary

A good tomato soup starts in the oven, not in the pot: roasting concentrates sugars and lowers acidity better than any teaspoon of sugar. About 185 calories per bowl with cream, about 125 without it, and a spoonful of olive oil that is effectively a condition for absorbing the lycopene. For more soups see Soups, and for the nutritional values of the vegetable itself — tomato.