Slow cooker tomato soup is full of flavour, comforting, creamy and rich and comes together so quickly. Roasted tomatoes form the basis of this simple recipe.
Delicious thick homemade soup is great whatever the weather and season.
In the winter you’ll love to tuck into this warming soup, with chunks of bread thickly spread with butter to dip in.
In summer if you have a glut of homegrown tomatoes, it is a great recipe to turn to to use them up.
Tomato soup is a favourite for many I think, as it reminds lots of us of being a child and those childhood meals of soup with lashings of buttered toast.
I find the flavour of this slow cooker tomato soup a pretty good rival to the well known brand!
It also has the benefit of being homemade and with no additives.
Soup is a great frugal dish for lunch or supper, served with crusty bread to dip in. Cooking the soup in your slow cooker instead of on the hob saves energy too!
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Roasted tomato soup
This recipe uses fresh tomatoes, preferably vine-ripened tomatoes for the best flavour.
You’ll get much better flavour from ripe tomatoes so choose carefully at the supermarket and if necessary leave your tomatoes in a bowl at room temperature for a couple of days to ripen before starting.
I like to use vine-ripened tomatoes, still on the vine, as I find these have that freshly picked taste whatever the season.
Often these are imported from Spain when out of season in the UK.
The olive oil used when roasting the tomatoes makes this soup lovely and rich even without adding cream.
You could stir in some double cream before blending to make it a cream of tomato soup, if you like it even more creamy.
For more slow cooker soups, you might like to try my slow cooker spiced parsnip soup or slow cooker sweet potato soup as well.
Ingredients
These are the ingredients you will need. You’ll find the quantities together with the full directions in the recipe card at the bottom of the post.
- vine-ripened tomatoes – this type of tomato is usually available all year round. The flavour of these is much better than your basic salad tomatoes so I recommend this type if you can get them.
- red onion – adds sweetness to the soup.
- cloves of garlic – these are roasted with the tomatoes to add their distinctive flavour.
- olive oil – for roasting the tomatoes. Choose a normal olive oil rather than extra virgin as it stands up better to being used in cooking (cheaper too!).
- mixed herbs – for a boost of fragrant flavour.
- vegetable stock cube – use your preferred stock cube, to add further depth of flavour. You can use chicken stock instead if you prefer.
- sugar – a teaspoon of sugar (caster or granulated can be used) balances the slight bitterness you can get with tomatoes. If your tomatoes are not fully ripe or not very sweet, you might need to taste the soup and add another teaspoon before dishing up.
- tomato puree – to intensify the tomato flavour.
- freshly boiled water
- salt and pepper
Instructions
Before you start, read my step-by-step instructions, with photos, hints and tips so you can make this slow cooker tomato soup recipe perfectly every time.
Scroll down for the recipe card with quantities and more tips at the bottom of the page.
Cut each tomato in half and place in a baking tray, drizzle with olive oil and crush the cloves of garlic and add.
Roast for approx. 35 mins at 180°C (350°F).
Put chopped red onion, roasted tomatoes and any juices from the pan in the slow cooker. Add two of the cloves of garlic (squeeze the soft garlic out of the skin), the mixed herbs, vegetable stock cube, 400 ml (1.5 cups) water, sugar and tomato puree.
Cook on high for approx. 3 hours or on low for 6-7 hours.
Blend using a stick blender or jug blender until smooth.
Serve with black pepper to taste and some torn basil leaves to decorate.
Hint: for a chunky tomato soup, cut the tomatoes into smaller pieces before roasting and when blending only blend half of the quantity, then add the blended part back to the unblended.
Substitutions
This recipe is vegetarian.
To make it vegan, check that your stock cube is vegan. If adding cream, use a vegan cream alternative.
To ensure the recipe is gluten-free, make sure you use a gluten-free stock cube (Knorr and Kallo have gluten-free options, while Oxo and Bisto contain gluten or wheat).
Variations
- Red pepper – for a red pepper and tomato soup add one or two red peppers cut into chunks into the baking tray before roasting the tomatoes. Then follow the recipe as given.
- Spicy – add chilli flakes or a sliced red chilli (remove the seeds if desired to reduce the heat) while cooking.
- Creamy – stir through some double cream or creme fraiche before serving.
Equipment
- oval 3.5 litre slow cooker
- chopping board
- measuring jug
Storage
Allow the soup to cool then store in the fridge for 3 days in a covered container.
Freeze for up to 6 months.
FAQ
I don’t peel tomatoes for this recipe as I have a power blender that blitzes it completely smooth. Removing the skin from tomatoes takes up precious extra time too. The tomato skin also adds depth of flavour – think of the summer sun shining on the tomatoes and making them turn red!
There is no need to remove seeds from tomatoes when making tomato soup. Think about when you eat tomatoes normally, the seeds don’t taste of anything. If you have a powerful blender it will blend them to nothing. If your preference is to remove them, cut the tomatoes in half horizontally (not through the stem), squeeze and scrape the seeds out with a teaspoon, before roasting.
Allow it to cool, then store in the fridge for up to 3 days.
Yes, you can freeze this tomato soup, for up to six months.
Recipe
Slow Cooker Tomato Soup
Ingredients
- 1.2 kg tomatoes vine-ripened
- 1 tbsp olive oil
- 5 cloves of garlic
- 130 g red onion chopped roughly
- 2 tsp mixed herbs
- 1 vegetable stock cube
- 400 ml water freshly boiled
- 1 tsp sugar caster or granulated
- 2 tbsp tomato puree
- 1 handful basil leaves
- black pepper
Equipment
Instructions
- Cut each tomato in half and place in a baking tray, drizzle with olive oil and crush the cloves of garlic and add.1.2 kg tomatoes, 1 tbsp olive oil, 5 cloves of garlic
- Roast for approx. 35 mins at 180°C (350°F).
- Put chopped red onion, roasted tomatoes and any juices from the pan in the slow cooker. Add two of the cloves of garlic (squeeze the soft garlic out of the skin), the mixed herbs, vegetable stock cube, 400 ml (1.5 cups) water, sugar and tomato puree.130 g red onion, 2 tsp mixed herbs, 1 vegetable stock cube, 400 ml water, 1 tsp sugar, 2 tbsp tomato puree
- Cook on high for approx. 3 hours or on low for 6-7 hours.
- Blend using a stick blender or jug blender until smooth.
- Serve with black pepper to taste and some torn basil leaves to decorate.1 handful basil leaves, black pepper
Notes
- Adjust the seasoning as you prefer. For example, you might like to add other fresh or dried herbs, or any other spices that you like.
- This recipe is vegetarian.
- To make it vegan, check that your stock cube is vegan. If adding cream, use a vegan cream alternative.
- To ensure the recipe is gluten-free, make sure you use a gluten-free stock cube (Knorr and Kallo have gluten-free options, while Oxo and Bisto contain gluten or wheat).
- Red pepper – for a red pepper and tomato soup add one or two red peppers cut into chunks into the baking tray before roasting the tomatoes. Then follow the recipe as given.
- Spicy – add chilli flakes or a sliced red chilli (remove the seeds if desired to reduce the heat) while cooking.
- Creamy – stir through some double cream or creme fraiche before serving.
- Allow the soup to cool then store in the fridge for 3 days in a covered container.
- Freeze for up to 6 months.
Andrea says
Looks so comforting, creamy and delicious. Perfect on a dreary day.
Tavo says
easy to make and tasty! It was perfect for a chilly night!
bakingqueen74 says
brilliant!
Gina says
Tomato soup and a grilled cheese is the best way to warm from the cold. So good!
Holley says
This is the creamiest tomato soup! I love this recipe!
Gail Montero says
Roasting the tomatoes add that extra depth of flavor to this yummy sauce! Love it!