I grew the onion harvest I dreamed of! There are only so many onions you can hang in the pantry before you start wondering what else you can do with them. Sadly, I don’t have a nice cool basement or root cellar. So after the pantry is full of cured onions and I’ve chopped and frozen a winter supply, I still have a pile of onions on my kitchen island.
Pressure canning French onion soup is one of my favorite answers.
Slowly cooked onions, beef broth, thyme, and dry white wine make a deeply savory soup base that can go straight onto the pantry shelf. Later, I can open a jar and turn it into classic French onion soup topped with toasted bread and bubbling Gruyère, use it to add incredible flavor to a Sunday pot roast, or simply heat it for an easy dinner.
And you don’t need a big garden to make it.
If onions are on sale at the grocery store, stock up. Pick up a big bag from a local farm stand or farmers’ market. If you grow only a few onions yourself, combine what you grew with purchased onions.
That’s the beauty of building a homemade pantry. It’s less about where every ingredient came from and more about taking advantage of good food when it’s plentiful.
My onions come from the 45-foot garden bed I plant with onions every spring.
My motto is grow what you can. Preserve what you have. Use it to make real food easier later.
If you did grow your own this year, here’s how I cure mine for long storage before any of them make it into a soup pot.
Why You’ll Love Having French Onion Soup in the Pantry
There is something immensely satisfying about preserving a garden harvest, but I especially love putting up foods that make future meals easier.
A jar of French onion soup does exactly that.
The time-consuming part —slicing and slowly cooking all those onions—is already done. Instead of beginning dinner with a cutting board full of onions, I can pull a jar from the pantry and already be halfway there.
Use a jar to:
- Make classic French onion soup with toasted baguette and melted cheese.
- Add rich onion flavor to a Sunday beef roast.
- Serve a simple bowl of soup alongside a sandwich or salad.
- Use the broth and onions as a flavorful starting point for other beef dishes.
- Keep an easy pantry meal on hand for days when cooking completely from scratch isn’t happening.
Because from-scratch cooking doesn’t mean you have to start from scratch every single night.
Sometimes you did the work months ago and put it in a jar.
What Is French Onion Soup?
French onion soup, or soupe à l’oignon, is a traditional French soup built around one very humble ingredient: onions.
The onions are slowly cooked until their sharp raw flavor gives way to something sweet, savory, and deeply browned. They’re combined with broth (typically beef broth in the version most Americans recognize) and often dry wine and herbs.
For classic French onion soup, the hot soup is ladled into oven-safe crocks, topped with toasted bread and cheese, and broiled until the cheese is melted, browned, and gloriously bubbly.
That final cheesy version is often referred to as soupe à l’oignon gratinée. But in truth, what is French onion soup without the toasted bread and cheese?
The ingredients aren’t particularly fancy. The flavor comes from giving the onions enough time to develop properly.
French onion soup is apparently another case where patience is an ingredient.
The Best Onions for French Onion Soup
Yellow onions — the traditional choice
For a classic French onion soup, yellow onions are the go-to pick.
They have enough natural sweetness to caramelize beautifully but retain a good savory onion flavor. After their long cooking time, they develop the rich, complex flavor most people associate with French onion soup.
They’re also readily available and economical, which matters when you’re buying or harvesting onions by the pound rather than by the onion.
Can I use sweet onions?
Yes. Honestly, this is what I use most of the time. Walla Wallas are the variety I grow the most of, so more often than not, they’re what actually goes into my canned French onion soup, not the classic yellow onion. Just keep in mind the finished soup will have a sweeter flavor than the traditional version.
If you grow Walla Walla onions, this can also be a practical way to preserve some of your harvest, because sweet onions don’t have the same long storage life as good storage varieties.
How Thick Should You Slice Onions for French Onion Soup?
I like onions sliced approximately ⅛ inch (3 mm) thick.
Thin slices soften and caramelize evenly, but at ⅛ inch they’re substantial enough to leave some lovely onion texture in the finished soup.
That’s particularly important when pressure canning because those onions aren’t finished cooking when they leave the Dutch oven. They’ll undergo additional heat during pressure processing and again when the soup is reheated.
Slice Your Onions Pole to Pole
Instead of cutting the onions crosswise into rings, I prefer slicing them pole to pole (from the stem end toward the root end).
Cut the onion in half through the root and stem, peel it, and then make thin slices following that same direction.
This cuts more along the natural structure of the onion and gives you longer strands that hold their shape better through prolonged cooking.
A mandoline works wonderfully for this and makes quick work of a large batch. Set it to approximately ⅛ inch or 3 mm.
And please use the hand guard or a cut-resistant glove. The mandoline doesn’t care how much soup you still have left to make — I learned that one the hard way, and these days I mostly just reach for a chef’s knife.
The Wine in This Recipe
The tested recipe calls for 3 cups dry white wine, cooked right into the base, not added later. As the onions finish caramelizing, the wine goes in gradually while you scrape up the browned bits from the bottom of the pot, and it simmers down until it’s almost completely reduced before the broth is stirred in. That reduction is doing real work: it’s concentrating flavor and loosening everything that’s stuck to the pan, which becomes part of the soup.
The recipe simply calls for “dry white wine.” The specific bottle is up to you. I choose Sauvignon Blanc because its bright acidity balances the sweetness that develops as the onions cook. Other good options include Pinot Grigio, dry unoaked Chardonnay, or dry Chenin Blanc. Avoid sweet wines and heavily oaked, buttery wines. For this recipe, you want acidity and complexity, not a wine that dominates the pot.
There’s no need to buy an expensive bottle. Choose an inexpensive dry wine you’d be happy to drink on its own.
Beef Broth Makes a Difference
French onion soup has very few ingredients, which means the quality of each one matters.
I use my homemade pressure-canned beef broth whenever I have it in the pantry, made using the same tested-recipe approach — here’s how I pressure can beef broth if you want to keep some on hand.
Store-bought beef, chicken, or vegetable stock can also be used. The tested recipe allows any of the three. Choose one with a flavor you genuinely like because there aren’t many other ingredients available to hide behind.
Don’t Rush the Onions
This is the part of the recipe that makes French onion soup taste like French onion soup.
The onions need time.
At first they’ll soften and release a surprising amount of liquid. Eventually that moisture cooks away and the onions begin developing their characteristic golden-brown color and concentrated flavor. The tested method gives them a full hour covered to get properly tender before you even start browning them.
Keep the heat controlled and stir regularly, especially as they begin browning.
If you’re standing over the pot thinking, Surely these are done now, they’re probably not.
You want beautifully softened, caramel-colored onions, not merely translucent ones.
The first couple of times I used a pressure canner, I was nervous. Why? I am not sure; I think I may have heard old stories that were never confirmed. These days I use my All American pressure canner with confidence, since it’s built without a rubber gasket — just metal on metal, which means one less thing to wear out or worry about.
Pressure Canning French Onion Soup Safely
French onion soup is a low-acid food, so it must be processed in a pressure canner for shelf-stable storage. A boiling-water canner cannot safely process this soup.
This recipe is the tested French onion soup recipe from The All New Ball Book of Canning and Preserving, 2016 edition, followed exactly for what goes into the jar — not adapted, not adjusted for taste. I do add a bay leaf while the onions simmer, for a little extra depth, but I pull it out before ladling the soup into jars, so what’s actually processed matches the tested recipe precisely. When pressure canning, this is not the place to improvise with ingredients simply because they’d taste wonderful in a bowl of soup.
Ingredients such as cheese, bread, flour or other thickeners, cream, pasta, and rice should not be added to the jars before processing. Those are finishing ingredients, added after you open the jar.
That’s actually one of the things I like about preserving this as a soup base: the pantry jar stays versatile, and you decide exactly how to finish it when you’re ready to eat it.
French Onion Soup for Pressure Canning Recipe
Adapted from The All New Ball Book of Canning and Preserving, p. 290
Yield: about 8 pint jars or 4 quart jars
Ingredients
- 4 lb (2 kg) onions, thinly sliced
- 1 Tbsp salt
- 1 tsp ground black pepper
- 1 tsp dried thyme
- 1 dried bay leaf, optional
- 3 cups dry white wine
- 3 qt Beef Bone Broth (or commercial canned chicken, beef, vegetable stock or home canned beef broth).
Instructions
Step 1: Heat a 7.25-qt stainless steel or enameled Dutch oven over medium-low heat. Stir in onions, salt, and pepper. Cover and cook 1 hour, or until the onion is very tender, stirring occasionally.
Step 2: Uncover and cook, stirring constantly, until the onion is caramel-colored. Stir in the thyme, bay leaf, then add the wine a little at a time as you scrape up the browned bits from the bottom of the pot, letting it cook down gradually rather than all at once. Simmer until the wine has reduced to almost dry, about 10 minutes total. Stir in the broth and bring to a boil; reduce heat and simmer, uncovered, 15 minutes.
Step 3: Remove the bay leaf. Ladle the hot soup into hot jars, leaving 1-inch headspace. Remove air bubbles, wipe the jar rims, center the lids, and apply the bands fingertip-tight. Place the jars on the rack in a pressure canner containing 2 inches of simmering water (180°F). Repeat until all jars are filled.
Step 5: Place the lid on the canner and lock it. Adjust heat to medium-high. Vent steam for 10 minutes. Then bring the canner to pressure: 10 psi (weighted-gauge) or 11 psi (dial-gauge) at sea level to 1,000 ft. At higher elevations, adjust as follows:
| Elevation | Weighted-Gauge | Dial-Gauge |
|---|---|---|
| 0–1,000 ft | 10 psi | 11 psi |
| 1,001–2,000 ft | 15 psi | 11 psi |
| 2,001–4,000 ft | 15 psi | 12 psi |
| 4,001–6,000 ft | 15 psi | 13 psi |
| 6,001–8,000 ft | 15 psi | 14 psi |
| 8,001–10,000 ft | 15 psi | 15 psi |
Processing time does not change with altitude — only the pressure does.
Step 6: Process pint jars 60 minutes, quart jars 1 hour 15 minutes. Turn off the heat and let the canner cool to zero pressure naturally — never force-cool a pressure canner. Let stand 5 more minutes before removing the lid.
Cool jars in the canner 10 minutes, then remove and let cool undisturbed. Check seals before labeling and storing.
How to Turn a Jar Into Classic French Onion Soup
This is when all that work during onion season pays off.
Open a jar, and most of your dinner is already made. 1 quart makes 2 hearty dinner servings or 4 light lunch servings.
For about 1 quart of French onion soup base, you’ll need:
- 1 quart home-canned French onion soup
- 1 tablespoon butter
- 1 tablespoon Cognac, optional
- Baguette slices
- Gruyère, Emmentaler, or a combination of the two
Pour the soup into a saucepan and bring it to a gentle simmer.
For a slightly richer, French-bistro flavor, add the butter and Cognac and simmer for 2–3 minutes. The Cognac isn’t there to replace the wine, since your canned soup already has dry white wine cooked into it. Cognac just adds a warmer, deeper note on top of that. Since we always have Cognac in our backyard pub, The Grain Shed, I always add it and think it really elevates the flavor.
Meanwhile, toast slices of baguette until lightly golden and fairly dry.
Ladle the hot soup into oven-safe crocks. Place toasted baguette over each serving and generously cover it with freshly grated cheese.
Place the crocks under the broiler until the cheese is melted, bubbling, and browned in spots. Watch it closely — this is the step where “almost done” turns into “burnt” in about ninety seconds.
Serve immediately and remember those crocks are extremely hot.
Gruyère vs. Emmentaler for French Onion Soup
The book’s own version pairs Swiss and Gruyère. My preference runs a little different.
Gruyère is my first choice because it has a rich, nutty, slightly complex flavor that stands up beautifully to the beef broth and caramelized onions.
Emmentaler is milder, buttery and nutty, and melts beautifully.
For an especially good topping, try:
⅔ Gruyère + ⅓ Emmentaler
You get the deeper flavor of Gruyère along with the lovely melt of Emmentaler.
If you have only one of them, don’t let that stop you. Either makes an excellent bowl of French onion soup.
No Pressure Canner? Make It for Dinner Instead
You don’t have to be a canner to enjoy this recipe.
Prepare the soup through the cooking portion (steps 1–2 above) and serve it rather than putting it into jars. Toast your baguette, grate the cheese, ladle the soup into crocks, and finish everything under the broiler.
This recipe makes a big pot — about a gallon of soup, enough for 8 hearty bowls, or closer to 10 if you’re serving it as a starter before a main course. Good for a crowd, or good for a family with leftovers for lunch tomorrow.
That’s one reason I wanted this recipe to be useful beyond preserving.
Some readers will grow their onions and pressure-can a dozen jars.
Some will come home from the farmers market with a big bag of onions and make several jars.
And some will pick up four pounds of onions at the grocery store and make French onion soup for Sunday dinner.
| Fresh-Made Same Night | Canned Base | |
|---|---|---|
| Active cooking time | ~1 hr 45 min (onions + wine reduction + simmer) | Done in advance — none on the night you eat it |
| Time to table | ~2 hours, start to finish | ~15–20 min (simmer + broiler) |
| Shelf life | Eat within a few days | Shelf-stable for months |
| Best for | A slow weekend when you want to cook | A weeknight, or when the pantry needs to do the work |
Using French Onion Soup for Sunday Pot Roast
This may be my second favorite reason for keeping these jars in the pantry.
French onion soup makes a wonderful flavor base for a beef roast. You’ve already got onions, beef broth, wine, and seasonings together in one jar.
Instead of reaching for a packet of onion soup mix, you can reach for something you made yourself.
Pour the soup around your roast and use it as part of the braising liquid, adjusting the other liquid and seasonings in your pot-roast recipe accordingly.
As the beef cooks, the onion-rich broth becomes part of the gravy and gives the roast wonderful savory flavor.
I like to substitute this French onion soup base for the beef broth in my Braised London Broil in the Oven.
More Ways to Use Canned French Onion Soup
Once you start thinking of these jars as an onion-and-beef-broth cooking base rather than something that can only become a bowl of soup, they’re even more useful.
Try using a jar as a starting point for:
- Beef stew
- Braised beef
- Beef and noodles
- Gravy for mashed potatoes
- Slow-cooked beef dishes
- A quick soup-and-sandwich dinner
This is exactly the kind of food I want taking up space on my pantry shelves — something that gives me options.
What If You Don’t Grow Onions?
Buy them.
Really.
You don’t need a large garden or any garden to build a homemade pantry.
Watch grocery store sales and buy onions when they’re inexpensive. Visit your local farmers market toward the end of onion season and ask about buying in larger quantities. Check farm stands and local growers.
Preserving food has always been about taking advantage of abundance.
Sometimes that abundance happens 30 feet from your back door.
Sometimes somebody else grew it.
The useful skill is knowing what to do with it once you’ve got it.
Frequently Asked Questions
Can French onion soup be canned?
Yes, but only using a tested pressure-canning method. Because it’s low-acid, it can’t be safely water bath canned.
Can French onion soup be water bath canned?
No. French onion soup is a low-acid food and requires pressure canning for shelf-stable storage.
Do you have to cook the onions before canning them?
Yes. The onions are cooked until very tender, then caramelized, before being combined with wine and broth and packed into jars. Raw onions aren’t part of this method.
What is the secret ingredient in French onion soup?
Time, honestly. It takes a lot of patience to get these onions right, and a little splash of Cognac in the end doesn’t hurt either.
How can I make canned French onion soup more flavorful?
Most of the flavor work is already done — the wine is cooked right into the base during canning, not added later. What’s left to decide is how you finish it: a splash of Cognac while it reheats, a good melting cheese, and bread toasted enough to hold up under the broiler.
Can I add cheese before pressure canning?
No. Add cheese when you open the jar and prepare the finished soup.
Can I put bread in the jars?
No. The toasted baguette is added when serving.
Can I thicken French onion soup with flour before canning?
Do not add flour or other thickeners before canning. Keep the soup brothy during processing, and make any desired adjustments after opening the jar.
What is the best onion for French onion soup?
Yellow onions are the traditional choice — sweet enough to caramelize well, savory enough to hold their own. That said, Walla Wallas are what I grow most, so more often than not, they’re what actually goes into my jars.
How thin should I slice the onions?
About ⅛ inch or 3 mm is my preferred thickness. I like slicing them pole to pole so the onions retain longer strands after cooking.
What is the best wine for French onion soup?
The tested recipe calls for dry white wine, cooked into the base. My choice is Sauvignon Blanc, for its bright acidity — Pinot Grigio and dry Chenin Blanc also work well. Avoid sweet or heavily oaked wines.
Do I need to add Cognac?
Not at all. Cognac is an optional finishing touch when you open the jar and make classic French onion soup. The canned soup already has dry white wine cooked into it.
What cheese melts best on French onion soup?
Gruyère is my first choice. Emmentaler also melts beautifully. A combination of roughly two-thirds Gruyère and one-third Emmentaler gives excellent flavor and melt.
A Pantry Meal Worth Preserving
There are plenty of ways to preserve onions, but I especially love preservation projects that solve two problems at once.
This one helps me deal with a large onion harvest today and makes dinner easier months from now.
A row of French onion soup on the pantry shelf can become an easy bowl of soup on a cold night, bubbling crocks of classic French onion soup for company, or the beginning of a Sunday roast.
And if your onions came from the grocery store instead of your garden, it works exactly the same way.
That’s the kind of simple living I believe in. It isn’t about doing everything yourself. It’s about learning useful skills, making the most of what you have, and putting a little work in now that your future self will appreciate later.
Grow what you can. Preserve what you have. Use it to make real food easier later.
Tried this recipe?
Yellow onions, Walla Wallas, or whatever was on sale that week — tell me in the comments what went into your jars.
Simple Living ❤️ Country Style — one jar, three dinners, zero regrets.
Shop This Post
- All American 1930 21.5qt Pressure Cooker/Canner (The 921)-this is pressure canner I trust
- 7.25 qt. Le Creuset Enameled Cast Iron Round Dutch Oven
- Quart and/or pint canning jars
- Jar lifter – a must have in canning
- The All New Ball Book Of Canning And Preserving – this is where I first saw this recipe
More Posts You’ll Love
- Canning & Preserving Collection
- Comfort Foods Collection – where you will find more soup recipes
- Pressure Canning Beef Broth — From Bones to Shelf-Stable Jars
- Braised London Broil in the Oven — Fall-Apart Tender with Rich Gravy
French Onion Soup — Pressure Canned
Equipment
- 7.25 qt – stainless steel or enameled Dutch oven
- Pressure Canner
- Canning jars, lids and bands
Ingredients
- 4 lb 2 kg onions, thinly sliced (about ⅛ inch / 3 mm, pole to pole)
- 1 Tbsp salt
- 1 tsp ground black pepper
- 1 tsp dried thyme
- 3 cups dry white wine
- 3 qt Beef Bone Broth or commercial canned chicken, beef, vegetable stock or home canned beef broth)
- 1 bay leaf optional (added during simmering only — removed before jarring, not part of the tested ingredient list)
Instructions
- Cook the onions.
- Heat a 7.25-qt stainless steel or enameled Dutch oven over medium-low heat. Stir in onions, salt, and pepper. Cover and cook 1 hour, or until the onion is very tender, stirring occasionally.
- Caramelize and deglaze.
- Uncover and cook, stirring constantly, until the onion is caramel-colored. Stir in the thyme, bay leaf, then add the wine a little at a time as you scrape up the browned bits from the bottom of the pot, letting it cook down gradually. Simmer until the wine has reduced to almost dry, about 10 minutes total. Stir in the broth and bring to a boil; reduce heat and simmer, uncovered, 15 minutes. Remove the bay leaf before the next step.
- Fill the jars.
- Ladle the hot soup into hot jars, leaving 1-inch headspace. Remove air bubbles, wipe the jar rims, center the lids, and apply the bands fingertip-tight. Place jars on the rack in a pressure canner containing 2 inches of simmering water (180°F). Repeat until all jars are filled.
- Process.
- Place the lid on the canner and lock it. Adjust heat to medium-high. Vent steam for 10 minutes. Then bring the canner to pressure: see chart in notes.
- Process pint jars 60 minutes, quart jars 1 hour 15 minutes. Processing time does not change with altitude — only pressure does.
- Cool.
- Turn off the heat and let the canner cool to zero pressure naturally — never force-cool a pressure canner. Let stand 5 more minutes before removing the lid. Cool jars in the canner 10 minutes, then remove and let cool undisturbed, 12–24 hours.
- Check and store.
- Check seals before labeling and storing. Refrigerate and use within a few days any jar that doesn’t seal.
Notes
- This recipe is followed exactly as tested — no substitutions to wine, broth ratio, or added ingredients (cheese, bread, garlic, flour) before processing. Flavor additions belong at reheat, not in the jar.
- The optional bay leaf is added during the stovetop simmer only and removed before jarring — it never becomes part of the processed contents.
- 1 quart makes about 2 hearty dinner servings or 4 light lunch servings.
| Elevation | Weighted-Gauge | Dial-Gauge |
|---|---|---|
| 0–1,000 ft | 10 psi | 11 psi |
| 1,001–2,000 ft | 15 psi | 11 psi |
| 2,001–4,000 ft | 15 psi | 12 psi |
| 4,001–6,000 ft | 15 psi | 13 psi |
| 6,001–8,000 ft | 15 psi | 14 psi |
| 8,001–10,000 ft | 15 psi | 15 psi |
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Hi, I’m Yvonne — the voice behind Our Country Life. I share from-scratch recipes, garden know-how, and simple living inspiration rooted in real farmhouse life. Thanks for being here ❤️
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