Blended Soups
Cooking Skills: Soups and Stocks 1
Chapter 4 · Blended Soups
Skill goal
Sweat, simmer, blend and season so every smooth soup tastes of its main ingredient.
Shopping list for this chapter
The basics
A blended soup follows one method: sweat an onion slowly in oil or butter with a lid on until it is soft and sweet, add the main vegetable and stock, and simmer until tender. Then blend until smooth and season at the end. What changes from soup to soup is the vegetable and the finish. A potato added to a thin soup thickens it; a splash of cream makes it velvety; a squeeze of lemon makes it taste brighter.
Roasting the main vegetable first (tomatoes, peppers, cauliflower) gives a sweeter, deeper flavour than boiling it, and no wine is used here. Cooking Skills: Vegetables 1, chapter 6 made a first tomato soup and green soup; here the soups are different and the method is more careful. Hot blending is a real hazard: read the safety box before you start.
The method
- Sweat the onion in oil with a lid on, low heat, for 8 to 10 minutes. It should be soft and not browned.
- Add the main vegetable, stock and a potato (if thin), and simmer until all is soft.
- Blend carefully, using a stick blender in the pan or a half-full jug with a vented lid.
- Adjust the thickness with hot stock or water, and season at the end.
- Finish with acid and fresh herbs, or a spoon of cream, to lift the flavour.
| Soup | Main vegetable | Thickener | Finish |
|---|---|---|---|
| Roasted tomato and red pepper | Tomatoes, peppers | A slice of bread or potato | Basil, a swirl of yogurt |
| Pea and mint | Frozen peas | Potato | Mint, lemon |
| Cauliflower | Roasted cauliflower | Potato | Nutmeg, a little cream |
| Cream of mushroom | Chestnut mushrooms | Flour or potato | Cream, thyme, lemon |
Hot blending, hot oven and allergens
Blending hot soup: hot liquid expands in a sealed blender and can blow the lid off and scald you badly. The safest choice is a stick blender in a deep pan, held low with the head fully under the surface. With a jug blender, cool the soup for a few minutes, fill it no more than half, take out the small centre cap of the lid, cover it with a folded cloth, hold it down and start on the lowest speed.Hot pan and hot oil: roasting tins and frying pans for browning are very hot and fat spits. Use dry oven gloves, pull the shelf out a little before lifting a tray, put hot things on a heatproof surface and keep children away.
Hot milk and cream: milk and cream boil over in seconds and burn worse than water. Keep the heat low, stay at the pan, and add dairy at the end. Never boil a soup once it has cream, or it may split.
Allergens in soup and stock: celery is one of the 14 major allergens and is in most stocks and stock cubes. Check cubes for celery, gluten, milk, soya, mustard and sulphites, and tell guests what is in the pot, because soup hides ingredients.
Try it
Level 1 · Start here
Pea and mint soup
The quickest blended soup, and it keeps its colour because the peas cook for only a few minutes. A potato gives body without cream. Add the mint at the end, because heat turns it dull.
Ingredients (4 portions)
- 1 tbsp rapeseed oil
- 1 onion, chopped
- 1 potato (about 200 g), peeled and diced
- 700 ml vegetable stock, unsalted
- 500 g frozen peas
- 15 g fresh mint leaves
- 1 lemon, juice
- 3 tbsp plain yogurt, to serve
- Sweat the onion in the oil with the lid on for 8 minutes. Add the potato and stock and simmer for 10 minutes until the potato is soft.
- Add the peas and cook for 3 minutes only. Take off the heat and add the mint.
- Blend until smooth, season with salt, pepper and lemon, and serve with a spoon of yogurt.
Hot blending and allergens
Blending hot soup: hot liquid expands in a sealed blender and can blow the lid off and scald you badly. The safest choice is a stick blender in a deep pan, held low with the head fully under the surface. With a jug blender, cool the soup for a few minutes, fill it no more than half, take out the small centre cap of the lid, cover it with a folded cloth, hold it down and start on the lowest speed.Hot pot and hot steam: a big pan of simmering stock or soup is heavy and scalding. Keep the handle turned in, use a ladle rather than pouring, lift the lid away from your face, and keep children and pets out of the kitchen while you move it.
Allergens in soup and stock: celery is one of the 14 major allergens and is in most stocks and stock cubes. Check cubes for celery, gluten, milk, soya, mustard and sulphites, and tell guests what is in the pot, because soup hides ingredients.
Allergens: contains celery (stock) and milk (yogurt).
Level 2 · Roast
Roasted tomato and red pepper soup
Roasting the tomatoes, peppers and garlic concentrates their sugar and gives a deep, sweet, smoky soup. A slice of bread thickens it and avoids cream. This is different from the plain tomato soup in Cooking Skills: Vegetables 1, chapter 6.
Ingredients (4 portions)
- 800 g ripe tomatoes, halved
- 2 red peppers, deseeded and quartered
- 1 onion, quartered
- 4 garlic cloves, in their skins
- 3 tbsp rapeseed oil
- 500 ml vegetable stock, unsalted
- 1 slice of bread, torn
- 1 tsp sugar
- 1 tbsp red wine vinegar
- Heat the oven to 200°C (180°C fan, gas 6). Toss the tomatoes, peppers, onion and garlic with the oil, season, and roast for 35 to 40 minutes until soft and starting to blacken at the edges.
- Squeeze the garlic from its skins. Tip everything into a pan with the stock and bread and simmer for 10 minutes.
- Blend until smooth, add the sugar and vinegar, taste and season.
Hot oven, hot blending and allergens
Hot pan and hot oil: roasting tins and frying pans for browning are very hot and fat spits. Use dry oven gloves, pull the shelf out a little before lifting a tray, put hot things on a heatproof surface and keep children away.Blending hot soup: hot liquid expands in a sealed blender and can blow the lid off and scald you badly. The safest choice is a stick blender in a deep pan, held low with the head fully under the surface. With a jug blender, cool the soup for a few minutes, fill it no more than half, take out the small centre cap of the lid, cover it with a folded cloth, hold it down and start on the lowest speed.
Allergens in soup and stock: celery is one of the 14 major allergens and is in most stocks and stock cubes. Check cubes for celery, gluten, milk, soya, mustard and sulphites, and tell guests what is in the pot, because soup hides ingredients.
Allergens: contains celery and gluten (bread); sulphites (vinegar).
Level 2 · Roast
Cauliflower soup
Boiled cauliflower makes a bland soup; roasting turns it sweet and nutty. A potato gives creaminess and a splash of milk or cream smooths it. A pinch of nutmeg helps. Cauliflower is also a good vegan soup if you use oil and plant milk.
Ingredients (4 portions)
- 1 cauliflower (about 800 g), in florets
- 3 tbsp rapeseed oil
- 1 onion, chopped
- 1 potato, diced
- 2 garlic cloves, sliced
- 800 ml vegetable stock, unsalted
- 100 ml whole milk or plant milk
- 1 pinch nutmeg
- Heat the oven to 200°C (180°C fan, gas 6). Roast the florets with 2 tbsp oil and salt for 25 to 30 minutes until golden at the edges.
- Sweat the onion and garlic in the remaining oil for 8 minutes, add the potato, stock and cauliflower, and simmer for 15 minutes.
- Blend until very smooth, stir in the milk and nutmeg, warm gently (do not boil) and season.
Hot oven, hot blending, milk and allergens
Hot pan and hot oil: roasting tins and frying pans for browning are very hot and fat spits. Use dry oven gloves, pull the shelf out a little before lifting a tray, put hot things on a heatproof surface and keep children away.Blending hot soup: hot liquid expands in a sealed blender and can blow the lid off and scald you badly. The safest choice is a stick blender in a deep pan, held low with the head fully under the surface. With a jug blender, cool the soup for a few minutes, fill it no more than half, take out the small centre cap of the lid, cover it with a folded cloth, hold it down and start on the lowest speed.
Hot milk and cream: milk and cream boil over in seconds and burn worse than water. Keep the heat low, stay at the pan, and add dairy at the end. Never boil a soup once it has cream, or it may split.
Allergens in soup and stock: celery is one of the 14 major allergens and is in most stocks and stock cubes. Check cubes for celery, gluten, milk, soya, mustard and sulphites, and tell guests what is in the pot, because soup hides ingredients.
Level 3 · Cream
Cream of mushroom soup
Brown the mushrooms hard in a hot pan, in batches, to drive off water and build flavour, then soften the onion with them. Blend half the soup and leave half chunky for texture, and finish with cream and a squeeze of lemon.
Ingredients (4 portions)
- 500 g chestnut mushrooms, sliced
- 2 tbsp rapeseed oil
- 30 g butter
- 1 onion, chopped
- 2 garlic cloves, sliced
- 1 tbsp plain flour
- 700 ml mushroom or vegetable stock, unsalted (chapter 2)
- 4 sprigs thyme
- 100 ml double cream
- 1 lemon, juice
- Fry the mushrooms in the oil in 2 or 3 batches over a high heat for 5 minutes each until deep brown. Set a few aside for garnish.
- Soften the onion and garlic in the butter for 8 minutes, stir in the flour, then add the stock and thyme. Add the mushrooms and simmer for 15 minutes.
- Remove the thyme, blend half the soup, mix it back in, stir in the cream and lemon, and top with the reserved mushrooms.
Hot pan, hot blending, cream and allergens
Hot pan and hot oil: roasting tins and frying pans for browning are very hot and fat spits. Use dry oven gloves, pull the shelf out a little before lifting a tray, put hot things on a heatproof surface and keep children away.Blending hot soup: hot liquid expands in a sealed blender and can blow the lid off and scald you badly. The safest choice is a stick blender in a deep pan, held low with the head fully under the surface. With a jug blender, cool the soup for a few minutes, fill it no more than half, take out the small centre cap of the lid, cover it with a folded cloth, hold it down and start on the lowest speed.
Hot milk and cream: milk and cream boil over in seconds and burn worse than water. Keep the heat low, stay at the pan, and add dairy at the end. Never boil a soup once it has cream, or it may split.
Allergens: contains milk, gluten (flour) and celery (stock).
Experiments
Experiment
Stock or water
Flavour.
- Make two small pots of pea soup, one with stock and one with water.
Look for: Stock gives a fuller, savoury soup; water tastes thin and relies on the vegetable alone.
Experiment
Hot or cooled before blending
Texture and safety.
- Blend one batch after 10 minutes of cooling with a stick blender and compare with a batch blended straight from the heat.
Look for: The textures are the same, but cooling a few minutes makes it much safer; never blend sealed and boiling.
Experiment
Roasted or boiled vegetables
Sweetness.
- Cook two small pots of cauliflower soup, one from roasted cauliflower and one boiled.
Look for: The roasted one is nutty and sweet; the boiled one is plain and slightly sulphurous.
Experiment
A splash of acid at the end
Brightness.
- Taste a bowl of tomato soup with and without a teaspoon of vinegar.
Look for: Acid lifts the flavour and makes the soup taste less flat; it is often what a bland soup is missing.
Tasting notes
| What I tried | Method or amount | What I saw | What I thought | Will I do it again? |
|---|---|---|---|---|
| Pea and mint soup | ||||
| Roasted tomato and pepper soup | ||||
| Cauliflower soup | ||||
| Cream of mushroom soup | ||||
| Stock or water | ||||
| Hot or cooled before blending | ||||
| Roasted or boiled vegetables | ||||
| A splash of acid at the end |
Troubleshooting
| Problem | Likely cause | What to do |
|---|---|---|
| Soup tastes flat | Not enough salt or acid | Add salt and a squeeze of lemon or vinegar, a little at a time |
| Lumpy soup | Under-blended | Blend longer, or sieve for a very smooth finish |
| Too thick | Too much potato or reduced | Add hot stock or water |
| Too thin | Too much liquid | Simmer to reduce, or blend in a potato or bread |
| Dull green pea soup | Overcooked | Cook the peas for 3 minutes only |
| Curdled cream | Boiled after adding | Add cream off the heat and warm gently |
Hot blending, hot pot and leftovers
Blending hot soup: hot liquid expands in a sealed blender and can blow the lid off and scald you badly. The safest choice is a stick blender in a deep pan, held low with the head fully under the surface. With a jug blender, cool the soup for a few minutes, fill it no more than half, take out the small centre cap of the lid, cover it with a folded cloth, hold it down and start on the lowest speed.Hot pot and hot steam: a big pan of simmering stock or soup is heavy and scalding. Keep the handle turned in, use a ladle rather than pouring, lift the lid away from your face, and keep children and pets out of the kitchen while you move it.
Cooling and keeping stock: stock is an ideal place for bacteria to grow. Strain it, then cool it quickly in shallow containers or an ice bath, chill within 1 to 2 hours, and use within about 2 days (fish stock within 1 day) or freeze it. Never leave a big pot to cool slowly on the hob or worktop overnight. Reheat until steaming hot all the way through.
Checkpoint: can you do this now?
- I can sweat an onion without browning it.
- I can blend hot soup safely.
- I can thicken a soup without flour.
- I can season a soup with salt and acid.
- I can roast vegetables for a sweeter soup.
Next chapter
Cooking Skills: Soups and Stocks 1, chapter 5 is Hearty Soups: lentils, beans and meat in thick, filling bowls.