Leftover mashed potatoes sitting in your fridge? Don’t let them go to waste when you could transform them into this incredible Mashed Potato Soup that tastes like it came straight from a cozy bistro.
This soup takes something simple and turns it into pure comfort in a bowl. The creamy base gets elevated with crispy bacon, sharp cheddar, and just enough garlic to make your kitchen smell amazing.
I first made this on a particularly cold Tuesday when I had a bowl of leftover mashed potatoes and absolutely no desire to go grocery shopping.
What started as a “clean out the fridge” moment became a recipe I now make on purpose, even when I don’t have leftovers.
The best part? It comes together in less than 30 minutes. You’re basically starting with potatoes that are already cooked and seasoned, so half the work is already done.
| Quick Recipe Summary | |
|---|---|
| Prep Time | 10 minutes |
| Cook Time | 20 minutes |
| Total Time | 30 minutes |
| Servings | 6 bowls |
| Difficulty Level | Easy |
Why You’ll Love This Mashed Potato Soup
This soup checks every box for an easy weeknight dinner that feels special. The texture is impossibly creamy without being heavy, and the bacon adds a smoky richness that makes each spoonful better than the last.
It’s also incredibly forgiving. Your mashed potatoes were too thick? No problem. Too garlicky? Even better. This recipe adapts to whatever you’ve got on hand.
Here’s what makes it stand out:
- Uses leftovers brilliantly – Transforms yesterday’s side dish into tonight’s main event
- Ready in 30 minutes – Faster than ordering takeout
- One pot wonder – Minimal cleanup means more time to actually enjoy your meal
- Crowd-pleaser – Even picky eaters go back for seconds
- Budget-friendly – Uses simple pantry staples and ingredients you probably already have
- Customizable – Easy to make it your own with different toppings and mix-ins
If you’re looking for more ways to use up leftover potatoes, you’ll love my Mashed Potato Pancakes.
Ingredients
This soup comes together with ingredients you likely have in your kitchen right now. The beauty of starting with leftover mashed potatoes means you’re already halfway done.
- 2 cups leftover mashed potatoes
- 4 cups chicken broth or vegetable broth
- 1 cup whole milk
- ½ cup heavy cream
- 4 slices bacon, chopped
- 1 medium onion, diced
- 3 cloves garlic, minced
- 2 tablespoons butter
- 1 cup shredded cheddar cheese
- 3 green onions, sliced
- 1 teaspoon dried thyme
- ½ teaspoon salt
- ¼ teaspoon black pepper
- Sour cream for topping
Kitchen Equipment Needed
You don’t need any fancy gadgets to make this soup. Just a few basic tools that you probably use every day.
- Large soup pot or Dutch oven
- Wooden spoon or silicone spatula
- Sharp knife
- Cutting board
- Measuring cups and spoons
- Immersion blender (optional, for extra smooth texture)
- Ladle for serving
Read Also: Leftover Mashed Potato Recipes
Recommended Products for This Recipe
I’ve tested this recipe dozens of times, and these specific products consistently deliver the best results.
They’re investments that will elevate not just this soup, but countless other recipes too.
1. Le Creuset Enameled Cast Iron Dutch Oven
This Dutch oven distributes heat so evenly that you’ll never have hot spots burning your aromatics.
The heavy lid traps moisture perfectly, and the enameled interior makes cleanup incredibly easy even when cheese gets stuck to the bottom.
2. KitchenAid Immersion Blender
While you can absolutely make this soup without blending, an immersion blender gives you restaurant-quality smoothness in seconds.
No need to transfer hot liquid to a countertop blender, which saves time and reduces mess.
3. Tillamook Sharp Cheddar Cheese
The quality of your cheese makes a huge difference here. Tillamook sharp cheddar melts smoothly without getting grainy and adds that perfect tangy bite that balances the richness of the cream.
4. Applegate Naturals Bacon
For the bacon, I always reach for Applegate Naturals. It’s uncured, has no artificial ingredients, and crisps up beautifully without leaving that weird chemical aftertaste that some bacon has.
Step-by-Step Instructions: How to Make Mashed Potato Soup
Follow these detailed steps to create the creamiest, most flavorful mashed potato soup. I’ve broken down each stage so even first-time soup makers can nail this recipe.
1. Cook the Bacon
- Place chopped bacon in your cold soup pot
- Turn heat to medium and let the bacon slowly render its fat
- Cook for 6-8 minutes, stirring occasionally, until crispy and golden brown
- Use a slotted spoon to transfer bacon to a paper towel-lined plate
- Leave about 2 tablespoons of bacon fat in the pot (drain excess if needed)
2. Sauté the Aromatics
- Keep the pot on medium heat with the reserved bacon fat
- Add diced onion to the pot and cook for 4-5 minutes until softened and translucent
- Stir in minced garlic and cook for 1 minute until fragrant
- Add butter and let it melt completely
- The butter adds extra richness and helps prevent the garlic from burning
3. Build the Soup Base
- Pour in the chicken broth and stir to scrape up any browned bits from the bottom
- Add your leftover mashed potatoes to the pot
- Use a wooden spoon or whisk to break up the mashed potatoes and incorporate them into the liquid
- Bring the mixture to a gentle simmer over medium heat
- Stir frequently to prevent sticking and ensure even heating
4. Add the Dairy
- Once the soup is simmering and the potatoes are fully incorporated, reduce heat to low
- Slowly pour in the whole milk, stirring constantly
- Add the heavy cream and stir until completely combined
- Sprinkle in the dried thyme, salt, and black pepper
- Let the soup simmer gently for 5 minutes to marry the flavors (don’t let it boil or the dairy might separate)
5. Incorporate the Cheese
- Remove the pot from heat (this prevents the cheese from becoming stringy or grainy)
- Add shredded cheddar cheese in three batches, stirring until each addition is fully melted before adding more
- The residual heat will melt the cheese perfectly without breaking it
- Taste and adjust seasoning with additional salt and pepper if needed
6. Finish and Serve
- Ladle the hot soup into bowls
- Top each serving with reserved crispy bacon
- Add sliced green onions for a fresh pop of color and mild onion flavor
- Dollop sour cream on top
- Serve immediately while hot and creamy
For another comforting potato dish, check out my Cajun Potato Soup.
Tips for The Best Mashed Potato Soup
These tried-and-true tips will help you avoid common pitfalls and create the most delicious soup every single time.
- Use cold mashed potatoes – They’re easier to break up and incorporate smoothly into the broth
- Don’t skip the bacon fat – It adds incredible depth of flavor that butter alone can’t replicate
- Adjust consistency as needed – If your soup is too thick, add more broth; if too thin, simmer longer to reduce
- Remove from heat before adding cheese – This prevents the cheese from separating or becoming grainy
- Warm your bowls – Run them under hot water for a minute before serving to keep the soup hot longer
- Taste before adding salt – Your leftover mashed potatoes might already be well-seasoned
- Stir frequently – Potato-based soups love to stick to the bottom of the pot
- Use good quality broth – Since it’s a main ingredient, the flavor really comes through
Serving Suggestions
This soup is hearty enough to stand alone as a meal, but pairing it with the right sides takes it to the next level.
Serve this creamy soup with crusty bread for dipping, which soaks up every last drop. A simple side salad with a tangy vinaigrette cuts through the richness beautifully.
For a complete comfort food spread, consider these pairings:
- Garlic bread or Buttermilk Cornbread
- Mixed green salad with balsamic vinaigrette
- Roasted vegetables like brussels sprouts or carrots
- Grilled cheese sandwiches for dipping
- Air Fryer Chicken Wings for a heartier meal
You might also enjoy my Broccoli Cheddar Soup.
Variations of Mashed Potato Soup
One of the best things about this recipe is how easy it is to customize based on your preferences or what you have in your pantry.
- Loaded Baked Potato Soup – Double the bacon, add extra cheese, and top with chives
- Smoky Version – Use smoked cheddar and add a pinch of smoked paprika
- Lighter Option – Swap heavy cream for half-and-half and use turkey bacon
- Vegetarian РSkip the bacon, use vegetable broth, and add saut̩ed mushrooms for umami
- Spicy Kick РAdd diced jalape̱os with the onions and use pepper jack cheese
- Herb-Forward – Stir in fresh rosemary, thyme, and parsley at the end
- Protein Boost – Add shredded rotisserie chicken or leftover ham
- Garlic Lovers – Double or triple the garlic and add roasted garlic cloves
Storage and Reheating
Proper storage keeps this soup delicious for days, making it perfect for meal prep or enjoying leftovers throughout the week.
- Refrigerator – Store in an airtight container for up to 4 days
- Freezer – Freeze in portion-sized containers for up to 3 months (note: dairy-based soups can separate slightly when frozen)
- Reheating from fridge – Warm gently on the stovetop over medium-low heat, stirring frequently and adding a splash of broth or milk if needed
- Reheating from frozen – Thaw overnight in the refrigerator, then reheat on the stovetop
- Microwave option – Heat in 1-minute intervals, stirring between each, until warmed through
- Texture tip – If the soup thickens too much in the fridge, thin it with additional broth or milk when reheating
Another favorite: Potato Leek Soup.
Nutritional Facts
Here’s the approximate nutritional information per serving (based on 6 servings):
- Calories: 380
- Total Fat: 24g
- Saturated Fat: 13g
- Cholesterol: 70mg
- Sodium: 890mg
- Total Carbohydrates: 28g
- Dietary Fiber: 2g
- Sugars: 5g
- Protein: 14g
Note that these values are estimates and will vary based on the specific brands and quantities of ingredients you use.
Health Benefits of Key Ingredients
While this is definitely an indulgent comfort food, it does contain some nutritious ingredients that offer real health benefits.
The potatoes provide vitamin C, potassium, and vitamin B6, which support immune function and heart health.
Garlic contains allicin, a compound with anti-inflammatory and antimicrobial properties.
Additional benefits include:
- Onions – Rich in antioxidants and may support heart health
- Dairy products – Provide calcium for strong bones and protein for muscle maintenance
- Thyme – Contains vitamins A and C, plus antimicrobial properties
- Green onions – Offer vitamin K and beneficial plant compounds
- Bacon (in moderation) – Provides protein and B vitamins
For more nutritious soup options, try my Lentil Spinach Soup.
FAQs About Mashed Potato Soup
1. Can I use instant mashed potatoes instead of leftovers?
Yes, you can absolutely use instant mashed potatoes if you don’t have leftovers. Prepare them according to package directions, let them cool slightly, then proceed with the recipe.
The soup might be slightly less rich since instant potatoes don’t have the same butter and cream content as homemade, so you may want to add an extra tablespoon of butter.
2. How do I prevent the soup from being lumpy?
The key is to break up the mashed potatoes completely as you add the broth. Whisk vigorously or use an immersion blender after adding the broth to ensure a smooth consistency.
If you still have lumps, simply blend the soup for 10-15 seconds with an immersion blender until you reach your desired texture.
3. Can I make this soup ahead of time?
Absolutely, this soup actually tastes even better the next day as the flavors have more time to develop.
Make it up to 2 days ahead, store it in the refrigerator, and reheat gently on the stovetop.
Just be aware that it will thicken as it sits, so have extra broth on hand to thin it out when reheating.
4. What can I substitute for heavy cream?
You can use half-and-half for a lighter version, though the soup won’t be quite as rich. For a dairy-free option, try full-fat coconut milk or cashew cream.
Keep in mind that using lighter dairy products will result in a thinner soup, so you may need to add a bit more mashed potato to thicken it.
5. Why did my cheese get stringy or grainy?
This usually happens when cheese is added to soup that’s too hot or if the heat is too high.
Always remove the pot from the heat before adding cheese and stir it in gradually.
Using freshly shredded cheese instead of pre-shredded also helps, as pre-shredded cheese contains anti-caking agents that can affect texture.
Read Also: Mashed Potato Fritters
Conclusion
This Mashed Potato Soup proves that some of the best meals come from using what you already have.
It’s the perfect example of how leftovers can become something even better than the original dish.
The combination of creamy potatoes, smoky bacon, and sharp cheddar creates a soup that’s both comforting and satisfying. Make a batch this week and see how quickly it disappears.
Have you tried this recipe? I’d love to hear how it turned out for you or any creative variations you came up with. Drop a comment below and let me know what toppings you used.
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