Can this copycat Costco french onion soup recipe stand up to the store’s version?

by Alicia Butler, September 6, 2022

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 Costco French onion soup recipe stacks up to the big-box 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 Recipe Copycat Vs Costco’s

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

Curl up with a good thriller (might I recommend Imposter Syndrome, by Kathy Wang) or some literary fiction (like This Time Tomorrow by Emma Straub) and you’ve got the recipe for one cozy fall or winter weekend.

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.

Costco French Onion Soup Recipe Copycat 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. 

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. 

Planning on doing some leaf peeping this year? Make a batch of this to eat at your Airbnb on a Kancamagus Highway fall foliage tour or if you’re planning on spending Halloween in Salem.

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

Just like pumpkin pancakes with pancake mix, French onion soup is a perfect fall recipe.

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. 

These Costco french onion soup directions were 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 Recipe

Servings: 3