Sliced mushrooms, sweet onion, garlic, fresh thyme, rosemary, and red wine go into the slow cooker after a short sauté. A flour-thickened vegetable stock forms the base. One batch serves 6 and takes about 3 hours.

The red wine goes into the sauté pan with the mushrooms, not into the slow cooker. Deglazing with wine at that stage lifts the browned fond from the pan and carries it into the pot. Broth-only sauté does not lift that fond the same way, because the liquid stays too wet for browning.

The cream and cornflour go in during the last 30 minutes, not at the start. Added at the beginning, 2 to 3 hours of heat causes the cream to split and lose its body. Whisked together first and added as one mixture, they thicken the soup from within as the heat finishes.

Slow Cooker Cream of Mushroom Soup

Recipe by Shili MohamedCourse: SoupsCuisine: AmericanDifficulty: Easy

Servings

6

servings

Prep time

30

minutes

Cooking time

2

hours 

30

minutes

Calories

191

kcal

Slow Cooker Cream of Mushroom Soup with mushrooms, sweet onion, red wine, fresh herbs, and cream blended into a rich, smooth broth. Serves 6

Ingredients

• Sauté

• 60g unsalted butter (¼ cup)

• ~450g mushrooms (5 cups), sliced

• 2 sweet onions, sliced

• 4 cloves garlic, minced

• 1 tbsp fresh thyme, chopped

• 1 tbsp fresh rosemary, chopped

• 1 tsp Italian mixed herbs

• ¼ tsp red pepper flakes

• 120ml red wine (½ cup)

• ½ tsp salt, or to taste

• ½ tsp black pepper, or to taste

• Slow Cooker Base

• 950ml chicken stock or vegetable stock (4 cups)

• 30g plain flour (¼ cup), whisked into 240ml (1 cup) of the stock before adding
• Finish

• 240ml whipping cream (1 cup)

• 30g cornflour (¼ cup)

• To Serve

• Fresh thyme and parsley, to garnish

Directions

• Melt the butter in a large frying pan over medium-high heat. Add the mushrooms and cook for 5 minutes, stirring. Add the onions and garlic and cook for a further 4 to 5 minutes. Add the thyme, rosemary, Italian mixed herbs, and red pepper flakes and stir for 2 minutes. Pour in the red wine and cook for 1 minute, scraping any browned bits from the base of the pan. Season with salt and pepper. Transfer the mixture to the slow cooker.
• Whisk the flour into 240ml of the stock until smooth. Pour into the slow cooker along with the remaining stock and stir to combine.
• Cover and cook on HIGH for 2 to 2½ hours or LOW for 3 to 4 hours.
• In a small bowl, whisk the whipping cream and cornflour together until smooth. During the last 30 minutes of cooking, stir the cream mixture into the soup. If cooking on LOW, switch to HIGH. Cook until thickened.
• Use a hand blender to blend the soup to your preferred consistency, leaving some mushroom pieces for texture. Taste and adjust the seasoning. Ladle into bowls and garnish with fresh thyme and parsley.

FAQs

Why does the flour go into the stock before the slow cooker?

Flour whisked into cold stock dissolves before heat reaches it, so it thickens the soup rather than forming lumps. Added dry to a hot slow cooker, flour clumps and cooks unevenly, leaving starchy pockets in the finished bowl. Dissolving the full quarter cup in one cup of stock takes 30 seconds and keeps the whole pot smooth.

Can the red wine be left out or swapped?

Leaving out the wine is fine; replace it with the same volume of additional stock when deglazing the pan. The wine adds acidity and fruit that stock alone cannot replicate, so the flavour runs slightly flatter without it. A tablespoon of red wine vinegar stirred in during the last 10 minutes restores some of that sharpness.

Can this soup replace canned cream of mushroom soup in other recipes?

This substitutes well for canned cream of mushroom soup in casseroles, with a richer flavour and lower sodium. Use it as a direct 1:1 swap; one full batch yields roughly the same volume as two standard tins. Blending fully rather than partially gives a smoother consistency that works better as a sauce base.

What other slow cooker soup works well on the same week?

A second slow cooker soup that goes in the opposite direction covers a different night without any overlap. A slow cooker French onion soup on this site is broth-based and built from caramelised onions, with no cream in sight. Together the two cover opposite ends of the slow cooker soup range across one rotation.

What if a more filling slow cooker soup better fits the meal plan?

This soup is on the richer, creamy end; a grain-and-meat soup covers different ground for the second night. A slow cooker beef barley soup on this site builds a chunkier, meat-based bowl that sits at the other end of the register. Together the two give a slow cooker soup rotation with enough contrast to hold the week’s attention.