Costco French Onion Soup Copycat Recipe

Can Costco frozen french onion soup stand up to a homemade version?

by Alicia Butler, September 6, 2022

Costco French Onion Soup

Costco is known for hitting a lot of culinary home runs. From roasted chicken to raviolis to budget hot dogs and more, you can find a lot of deals that make Costco worth the membership. 

But its frozen foods are where Costco really shines. 

Not unlike Trader Joe’s, Costco really knows how to create microwaveable meals that can feed a whole family and taste great to boot. And the Costco French onion soup just happens to be one of these.

But what to do if you don’t have a Costco membership or don’t live near one of these big box retailers? You can still get a similar soup for a comparable price by making it yourself with my copycat recipe.

Find out how my homemade copycat recipe stacks up to the Costco frozen french onion soup, and get Costco french onion soup directions to make your own right at home (no Costco membership required!).

This post may contain affiliate links, so if you buy something after clicking on a link, I might (fingers crossed!) just get a little commission. Good news: I only recommend products that I love! Which means you can feel good about all of my recs.

Costco French Onion Soup Copycat Vs Costco’s

You’ll notice a few ingredient variations between my French onion soup and the Costco French onion soup.

Mostly, because I couldn’t get my hands on riboflavin and not because I’m an ingredient snob or anything. I also didn’t add sugar to my onions to help them caramelize, but you’re more than welcome to add a sprinkle of the stuff if your onions need a ‘lil help getting to that golden brown phase.

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Costco Frozen French Onion Soup Ingredients

Broth (water, cooked vegetables [onion, carrot, celery], sunflower oil, salt, onion and carrot powder, yeast extract, brown sugar, sugar, canola oil, roasted malted barley, flavor), Onions, Swiss cheese (milk, salt, bacterial culture, microbial enzyme, calcium chloride, cellulose), Croutons (enriched flour (wheat flour, niacin, reduced iron, thiamine mononitrate, riboflavin, folic acid), sugar, sunflower oil, yeast, salt, ascorbic acid), Contains 1.5% or less: enriched flour (wheat flour, niacin, reduced iron, thiamine mononitrate, riboflavin, folic acid), yeast extract, garlic, salt, spices, cellulose gum.

Copycat French Onion Soup Ingredients

I’m not going to beat around the bush: whenever you’re using stuff like riboflavin, folic acid, and sugar, food is just going to taste better. If you added MSG or a few dashes of Worcestershire sauce or soy sauce to this, it would probably pump up the flavor immensely. 

But this was my first shot at the Costco french onion soup recipe, so I stuck to the basic ingredients, including:

  • Butter
  • Onions
  • Garlic
  • Beef Bone Broth
  • Dry White Wine
  • Dry Sherry
  • Rye Bread
  • Gruyere Cheese (shredded)

Seasonings

  • Salt
  • Pepper
  • Fresh Thyme

Honestly, caramelized onions add a ton of flavor to anything. If you follow this recipe as is, you’ll still get a really flavorful soup. 

Making French onion soup from scratch can kind of be a serious b*tch. The reason? Carmelizing the onions takes foreeeever. 

Costco French Onion Soup VS Copycat Soup Prices

The Costco French onion soup sells for $9.99 for six, plus the cost of the Costco membership fee (about $0.164 per day per person) comes to $10.15 (so $1.69 per serving). My French onion soup cost:

  • Sweet onion: $1.00 (you can even use Costco sweet onions!)
  • Butter: $1.10
  • Garlic:  $0.30
  • Beef bone broth: $1.11
  • White wine: $0.53
  • Sherry: $0.003
  • Rye bread: $0.50
  • Gruyere cheese: $0.56

Total: $5.10/3 servings = $1.70

So, mine costs just one penny more per serving (if you don’t include the cost of the time it takes to make the soup, which I did not). But you could easily lower the price by using a deli Swiss, regular stock instead of bone broth, or a cheaper bread.

Whatever you do, don’t omit the wine and sherry. These ‘lil flavor bombs pack a punch and kind of “make” the whole flavor of the soup. 

Costco French Onion Soup Review

How does the Costco frozen French onion soup stack up against the homemade version?

I have to admit, it’s hard to beat the Costco brand, especially when you take into consideration the time it takes to make French onion soup from scratch.

My review of the Costco French onion soup? It’s pretty good (for a frozen soup!). 

It cooks pretty fast in the toaster oven or conventional oven, and it’s full of flavor. 

My one complaint is that it’s hard to break up the bread and the cheese in a lot of French onion soup (not just this French onion soup), and the Costco brand is no different.

I like to have some control over my bread to cheese to soup ratio, and I like to chop up the croutons into smaller, bit-sized pieces before adding it to the soup so I’m not stuck with a soggy, lumpy mess of bread and cheese while I’m eating. 

Costco French Onion Soup Directions: Tips for Making French Onion Soup

Reducing Cooking Time

Making French onion soup from scratch (instead of buying it directly from Costco) can kind of be a serious b*tch. The reason? Carmelizing the onions takes foreeeever. 

This recipe was partially adapted from a New York Times one (I started using it but got locked out by the paywall after my phone’s browser refreshed too many times), and the NYT recommends carmelizing the onions for around 45 minutes. 

Who has the frackin’ time to watch onions cook for 45 minutes? Def not me. 

So, I promptly started Googling, “How to make onions carmelize faster.” According to Serious Eats, adding a little baking powder to your onions and slightly increasing your cooking temperature can speed up this process. So I tossed the chopped onion in ⅛ teaspoon baking powder, turned up my stove to medium-high, and hoped for the best. 

The result? It might have sped up the cooking time a smidgen? It took about 20 to 30 minutes for the onions to brown (and the smaller pieces started getting dangerously crispy looking while the larger pieces were still milky white). 

Still, I only used one onion compared to the NYT’s three whole onions, which should have reduced the cooking time, anyway. 

Choosing Your Broth

I went for a beef bone broth, but you can always use vegetable or chicken broth, too, if you prefer.

A few months ago, I found beef bone broth powder on sale at Whole Foods. Since bone broth is so freakin’ expensive, I thought I’d give it a whirl. You get the equivalent of 27 cups of bone broth for $15, but I was still a little worried it would taste weird.

It turned out to be really good. And now I have powdered beef that I can use to flavor dishes I don’t want to water down with broth.

Costco French Onion Soup Copycat Recipe

Servings: 3

Ingredients
  • 2 tbl butter (unsalted)
  • 1 tbl butter (salted)
  • 1 sweet onion (chopped)
  • 3 cloves garlic (minced)
  • 20 oz beef bone broth
  • ⅓ cup dry white wine
  • 2 tbl dry sherry
  • Rye bread
  • Gruyere cheese (shredded)
Seasonings
  • Salt
  • Pepper
  • Fresh Thyme
Instructions

1. Chop the Onions and Garlic

Chop one onion. 

I like to chop most of the onion into small pieces and leave a few pieces longer. I hate the texture of long, stringy caramelized onions or feeling like I need to chew through my soup too much.

Mince the garlic.

2. Cook the Onions, Garlic, and Thyme

Heat a dutch oven on medium, and melt the two tablespoons of unsalted butter. 

When the butter is fully melted, add the onions and garlic. 

Season with salt and pepper (I added two pinches of salt and a few turns of the pepper mill). Add about a tablespoon of fresh thyme leaves (dried thyme is fine too if you are too overcome by the demands of late-stage capitalism lazy to grow your own). 

Turn up the heat to medium-high heat, and keep an eye on your onions, stirring regularly. 

When the smaller bits are getting a little crispy, I add another tablespoon of butter.

3. Deglaze the Pan

When your onions have a golden-brown color, it’s time to deglaze that pan. 

Add your dry white wine and stir, stir, stir, scraping the bottom of the pan as you go. Then, add your dry sherry.

4. Add the Broth

Add your broth, and turn your heat up to high. When the broth boils, turn it down to simmer.

5. Toast the Bread/Broil the Cheese

When your soup is simmering, toast your bread. I like to throw a slice of rye bread into the toaster on the highest setting so it’s super crispy.

Then, place your bread on a quarter-sheet pan (or even just a piece of tin foil), sprinkle generously with your shredded gruyere or swiss cheese, and stick it under the broiler.

I let it broil for about four minutes, added more cheese, and stuck it under the broiler for another three minutes. 

Chop your bread into smaller chunks as a gift for your future self because cutting through bread and cheese as it’s submerged in soup isn’t fun for anyone. 

Ladle your soup into a bowl and top with your cheesy rye croutons. Garnish your soup with a ‘lil sprinkle thyme because you’re not an animal. 

 

Products Mentioned in This Recipe

julia child

Mastering the Art of French Cooking

Sea Salt

Finishing Salt

Zoe EVOO

Zoe Extra Virgin Olive Oil

sheet pans

Sheet Pans