If you love making soups, stews, and sauces, having prepped and frozen classic French mirepoix on hand is a game-changer. This trio of vegetables is an aromatic mix of—yellow onion, carrot, and celery—and serves as the aromatic base for countless recipes. In this post, I’ll walk you through how to make and freeze traditional mirepoix ahead, ensuring you’re always ready to whip up a comforting dish with a great flavor base.
As a mom working full-time, I know how busy life can get, and sometimes, finding the time to prepare meals from scratch feels overwhelming. That’s why I came up with the idea of meal prepping for convenience this easy soup blend as we are in the thick of Canadian winter. It simplifies my cooking process during hectic weeks. Having prepped ingredients ready to go makes it easier to create flavorful dishes quickly without sacrificing quality or flavor.

Why You’ll Love Freezing Mirepoix
Time Saver: Prepping mirepoix ahead is a great way to ensure less time chopping when cooking, saving you valuable time on busy weeknights.
Cost-Effective: Buying vegetables in bulk, like a whole bunch of celery, two pounds of carrots, and five yellow onions, is more economical than smaller portions.
Space-Saving Storage: Laying the bags flat in your freezer keeps things organized and frees up space for other frozen goods.
A Brief History of Mirepoix
Mirepoix, a French culinary term, originated in French cuisine as a fundamental aromatic base for soups, stews, and sauces, forming the backbone of many classic dishes. The name “mirepoix” is derived from Gaston Pierre de Lévis, duc de Mirepoix, a 17th-century French nobleman whose family is believed to have popularized this combination of vegetables in cooking. The traditional mirepoix mix consists of two parts onion, one part carrot, and one part celery, creating a balance of sweetness and earthiness that forms an intensely flavorful foundation for a wide variety of dishes. The French term for this trio essentially translates to “creating a deeply flavorful start,” emphasizing its role in building rich, savory layers in everything from broths to sauces.

Mirepoix has inspired similar vegetable combinations worldwide, each contributing its twist to the concept of a flavorful base. The Italian sofrito often includes onions, garlic, and sometimes tomatoes, building complex flavors in pasta sauces, risottos, and stews. The Cajun holy trinity, consisting of onions, bell peppers, and celery, plays a pivotal role in Cajun and Creole cuisines, forming the foundation of iconic dishes like gumbo, jambalaya, and étouffée. These flavor bases are just as integral to the cuisine as mirepoix is to French dishes, contributing to the deep, comforting flavors that characterize these cultural, culinary traditions.
Similar to these regional counterparts, mirepoix, and its global variations are key to crafting flavorful soups, stews, braises, and other dishes that rely on aromatic vegetables to create a rich, hearty taste reminiscent of the humble beginnings of home cooking. These early days combinations have been passed down through generations, making them enduring staples in kitchens worldwide.
To Prepare Mirepoix for the Freezer
To prepare approximately six cups of classic mirepoix for freezing, gather a whole bunch of celery, two pounds of carrots, and five yellow onions. To keep the onions from being overtly annoying to chop up, put them in the fridge for 24 hours. By chilling the onions, you are slowing down their ability to release the compound that is reacting with your eyes. I learned this little trick while doing food prep in the food industry.


Now, you can start by washing the celery. Remove the cut at the end where the stalks are bunched together. This chunky piece we can discard. You will also want to remove the leaves of the celery. While the leaves are edible but not part of a traditional mirepoix blend. Cut the dried-out ends of the celery stalks off as well. Then, cut the celery into smaller pieces. Add them to a large bowl and move on to the carrots.


Cut either end of the carrots off using your sharp knife, and then use a vegetable peeler to take the outer skin off. The carrots will need a rinse before chopping, so add them to a large colander to run under cold water. When you’ve finished rinsing them, you can chop them into small rounds similar to the celery size. You can dice the carrots and celery in smaller dice if you prefer. I like a chunkier soup base, so larger pieces work for my family. It really depends on your personal preference. You will undoubtedly want to work with room-temperature carrots if you want to dice.

To dice carrots, it’s best to cut them into manageable pieces. Then, quarter and chop them into bite-sized pieces. Add those finished carrots to your celery in the bowl.

Next, you will be working on the chilled onions. I used five large yellow onions for this mix. Remove the ends and outer skin of the onion. Cut them in half and slice each half in half again. Chop while layering the flat side down into chunks or small pieces. Remember you want all the ingredients of this mirepoix to be uniform pieces. Add the onions to the bowl with the other vegetables, and thoroughly mix the blend using a wooden spoon or clean hand.


Divide the chopped vegetables into two large freezer bags, each holding about six cups of mirepoix. For added convenience, you can measure two-cup portions into smaller bags depending on your recipe needs. Once portioned, lay the vegetables flat in the freezer bags, pressing out as much air as possible to prevent freezer burn. This will also ensure even freezing and save on freezer space. Don’t forget to label each freezer bag with the date and contents before storing them flat in your freezer for up to three months. Perfect for making a few batches of soups or stews during the winter months.


Ingredients:
Celery: This green vegetable imparts a fresh, slightly herbal taste and adds a crunchy texture when cooked, enhancing the overall balance of flavors in the soup. Its mild flavor complements the other vegetables without overpowering them.
Carrots: Add a subtle sweetness and earthy flavor, balancing the onions’ sharpness. They also contribute a lovely color, making the soup more visually appealing.
Onions: This brings a natural sweetness and depth of flavor when sautéed, providing a savoriness that enhances the overall taste of the entire dish. They also help create the aromatic backbone for the soup.
When I want to use up other vegetables on hand, this is one of my favorite ways of incorporating them to avoid food waste. Adding them to your mirepoix mix can create a more personalized soup base. Adding aromatic vegetables like leeks, shallots, fresh thyme, or parsley stems can enhance the flavor profile and help reduce food waste. Leeks can be an excellent alternative for onions in your mix, providing a milder, sweeter flavor. If you prefer shallots, they offer a delicate, slightly sweet taste that can replace or complement onions. Fresh thyme introduces an earthy, herbal note, and parsley stems contribute a fresh, slightly peppery flavor.
When freezing a soup base mix, it’s essential to adjust the balance of your ingredients to maintain the right texture and flavor. You should reduce the amount of onions if you add leeks or shallots to keep the mix from becoming too onion-forward. These aromatic vegetables freeze well and can be portioned out in your soups, stews, and sauces for future use. By swapping in these additional vegetables, you can create a flavorful, aromatic base that’s versatile and great for using up what you already have in your kitchen.

Using Frozen Mirepoix in Recipes
Mirepoix is incredibly versatile and, when used as the base for soups, stews, and casseroles, it gives your dish gives foundational depth of flavor. To cook mirepoix, start by heating a little olive oil or butter in your soup pot or pan over medium heat. Add your chopped mirepoix (fresh or frozen) and sauté, stirring occasionally, until the vegetables become soft and aromatic. This process can take 5 to 10 minutes, depending on whether you’re using fresh or frozen mirepoix. The vegetables release their natural flavors as they sauté, enhancing your dish’s overall richness.
If you’re using frozen mirepoix, you can add it directly to the hot pan without thawing. It may release more moisture as it cooks, so you might need to cook it longer to allow the liquid to evaporate, intensifying the flavors. Once the mirepoix is softened and fragrant, add the rest of your ingredients, such as broth, meat, beans, or spices, to continue building your dish.
For inspiration, try my Easy Hearty Hamburger Soup Recipe, which eats like a meal, or my Roasted Tomato Chicken Soup. Both winter dishes benefit from using the aromatic flavor mirepoix adds, making them even more comforting and satisfying, especially on a cold night. Whether cooking from scratch or using frozen mirepoix, these soups are perfect for a cozy, hassle-free meal. By starting with mirepoix, you create a flavorful foundation that elevates your recipes, ensuring each bite is rich and satisfying.
I’d love to hear how you use mirepoix or other aromatic vegetable blends in your cooking! Do you have a favorite combination or a unique twist on the classic trio of aromatics? Share your thoughts and recipes in the comments below! As always, happy meal prep!
How to Freeze Mirepoix for Easy Meal Prep
Equipment
- 1 Large Bowl
- Cutting board
- Colander
- knife
- Vegetable peeler
- Freezer Bags
Materials
- 1 Bunch Celery Ends And Leaves Removed, Sliced
- 2 Lb Bag Carrots Peeled, Rinsed, Chopped/Diced
- 5 Lrg Onions Peeled Chopped/Diced
Instructions
- Chill onions in fridge overnight. This reduces burning eyes.
- Wash the celery cut off both the bunched end and the dry ends of each stalk. Remove and discard celery leaves.
- Using sharp knife cut the celery into smaller pieces on cutting board and add to bowl.
- Peel carrots and rinse under cold water in colander.
- Cut the carrots into similar sized pieces on the cutting board. Add to bowl.
- Remove onions from fridge and peel. Cut in both ends off and then cut in half.
- Lay flat side down and cut in half again. Continue cutting onion until the pieces are uniform with the celery and carrots.
- Add chopped onion to bowl with carrots and celery and using a spoon or clean hands mix together well.
- Using measuring cup divide the mixture into freezer bags.
- Lay freezer bags flat and push the mirepoix mixture as close to the opening as possible to release air before sealing.
- Be sure to label bags. Use frozen mirepoix within three months.