Creamy Potato Leek and Bacon Soup Base
A rich, silky soup base built on tender potatoes, caramelized leeks, and crispy bacon. The potatoes break down slightly into the cream to create natural body, while a mash of some potatoes adds velvety texture. This base can be served as-is or diluted with stock for a lighter soup.
Steps
Before you start
- Cut potatoes and leeks to uniform size so they cook evenly
- Have a slotted spoon and colander ready for the bacon
- Use a whisk or fork to mash potatoes—a food mill or blender over-purées this soup
Cook bacon until crispy
- In a large 5-quart (4.7 L) heavy-bottomed pot, cook the bacon pieces over medium heat, stirring occasionally, until the edges are browned and crispy, about 8–10 minutes.
- The bacon will render fat into the pot.
- Use a slotted spoon to transfer the bacon to a paper towel–lined plate, leaving the fat in the pot.
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Ready when: Bacon edges are browned and crispy
Tip: Don't discard the rendered bacon fat—it's the flavorful base for the soup.
Sauté leeks until soft
- Add the butter to the pot with the bacon fat.
- When the butter foams, add the sliced leeks and a small pinch of salt.
- Stir to coat.
- Reduce heat to medium-low and cook, stirring every 2 minutes, until the leeks are very soft and beginning to turn golden, about 12–15 minutes.
- The leeks should collapse and release their sweetness.
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Ready when: Leeks are very soft and light golden, almost melting in the pot
Tip: Cook leeks low and slow to bring out their natural sweetness; rushing will result in less flavorful soup.
Add potatoes and stock
- Add the cubed potatoes to the pot and stir well, making sure they are coated with the bacon fat and leek mixture.
- Pour in the chicken stock and add the thyme sprigs (if using).
- Increase heat to medium-high and bring to a boil, stirring occasionally.
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Ready when: Liquid is at a rolling boil
Simmer until potatoes are tender
- Once boiling, reduce heat to medium and simmer uncovered until the potatoes are completely tender and easily pierced with a fork, about 12–15 minutes.
- Most of the potato pieces should start to break apart slightly.
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Ready when: Potatoes fall apart when pressed with a fork; liquid looks slightly cloudy from starch
Tip: Don't overcook or the potatoes will turn to mush; you want some structure for mashing.
Remove thyme and mash potatoes
- Remove and discard the thyme sprigs.
- Using a potato masher or large fork, coarsely mash about half of the potatoes in the pot, leaving some chunks and pieces.
- The soup should have a rustic texture with visible potato chunks suspended in the creamy broth.
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Ready when: About half the potatoes are broken down; the other half remain as soft chunks
Tip: Stop mashing before the soup becomes smooth; you want creamy texture from the broken potatoes, not a purée.
Stir in cream and bacon
- Pour the heavy cream into the pot and stir well to combine.
- Add the reserved crispy bacon back into the soup.
- Taste and season with kosher salt and freshly ground black pepper to your preference.
- Simmer gently for 2–3 minutes to let flavors meld, stirring occasionally.
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Ready when: Cream is fully incorporated; bacon is evenly distributed
Tip: Taste before adding salt—stock and bacon are both salty, so you may need less than you expect.
Good to know
Tips
- This is a hearty soup base; you can stretch it further by adding 2–4 cups (480–960 ml) of additional stock or broth when serving. Stir in slowly to reach your preferred consistency.
- For extra flavor depth, add a tablespoon of crispy sage leaves, snipped chives, or a splash of white wine after removing the thyme.
- If soup breaks or looks curdled (rare but possible), whisk in a little cold milk or cream off the heat, stirring constantly, to re-emulsify.
- Leeks can trap dirt between layers—slice them lengthwise first, rinse thoroughly between the layers, then slice into half-moons to ensure they're clean.
Make ahead
You can make this soup up to 3 days ahead. Cool completely, then refrigerate in an airtight container. Reheat gently over medium-low heat, stirring occasionally and adding a splash of stock or cream if needed to loosen it (soup thickens as it cools).
Storage & reheating
Room temperature: up to 2 hours. Refrigerator: up to 3 days in an airtight container. Freezer: up to 3 months (thaw overnight in the fridge, then reheat gently). To reheat: warm over medium-low heat on the stovetop, stirring often and adding stock or cream as needed to reach desired consistency.
Substitutions
- heavy cream → Half-and-half or whole milk mixed with a little cornstarch slurry. The soup will be less rich and slightly thinner. If using milk, mix 1 tbsp cornstarch with 2 tbsp cold milk, stir into the hot soup, and simmer for 2 minutes to thicken.
- unsalted chicken or vegetable stock → Vegetable stock or water. Vegetable stock works well for a lighter soup. Water is fine but will produce a milder, less savory base—add extra salt and a bay leaf if using water.
- thick-cut bacon, sliced into ½-inch (1.3 cm) pieces → Pancetta, smoked ham, or crispy shallots. Pancetta and ham will give similar smoky depth. Crispy shallots work for vegetarian version but lose the smokiness.
- russet potatoes, peeled and cut into 1-inch (2.5 cm) cubes → Yukon Gold potatoes. Yukon Golds are creamier and slightly less starchy than russets; reduce simmer time by 2–3 minutes as they cook faster.
