The Secret To A Perfect Traditional French Onion Soup

French onion soup is a rich and warming meal. The main flavors come from the caramelized onions and the intense beef stock.

If you have never had French onion soup before, you might have thought it was vegetarian, but the most important ingredient is beef stock. Without it, you cannot get the deep richness this soup is known for.

The Secret To A Perfect Traditional French Onion Soup

If you are vegetarian, scroll down to the bottom of our recipe. We have a special ingredient to help you imitate the all-important beef stock.

Quick Answer: Traditional French Onion Soup

To take your french onion soup to another level, you need one simple secret ingredient – beef stock. This gives you the base flavor and really brings out the onion flavor goodness. Plus, you should caramelize your onions before making the soup. Taste the sweet and smoky flavor and you’ll never go back.

The Special Ingredient

We kind of ruined the surprise already. The secret ingredient is the hidden beef stock. The depth of flavor the stock brings adds a warming richness that cannot be replaced.

If you thought this soup was all about onions, you’d be wrong. In fact, the overall flavor will end up surprising you.

But as with everything, you can’t pick up any old stock, and you can’t simply throw some onions into the pot.

To create a flawless French onion soup you need to perfect both ingredients.

How To Pick The Best Beef Stock

First things first, the key ingredient is beef stock, so you cannot buy any old brand. If you can splurge on one ingredient, make it the stock. The flavor it will add to your soup is incomparable.

The stock will act as your base flavor. It gives the meal body without adding extra textures.

If you don’t like beef stock, you can swap it for chicken, however, it won’t have the same richness. That being said, chicken stock is easier to find in grocery stores and you can always make chicken stock at home.

If you have the time, try out a few top-brand beef stocks and see which one has the largest body of flavor.

Caramelize Your Onions

The second important ingredient in this soup is its namesake. The onions you use don’t need to be top quality. It’s what you do with them that counts.

You need to caramelize them.

Our method below will walk you through the process, but we want to offer some context first.

Caramelizing your onions will create a subtle sweetness. It’s a time-consuming step but if you ignore this part of the process your soup may be too rich.

Balancing your beef stock and onions will help you make the perfect soup. If you skip this step, you might only take a few sips from your meal before needing a break.

Prepare yourself, as caramelizing onions should take you between 45 minutes to 1 hour. Anything less than this will not create the balancing sweetness you’ll need.

How To Make Traditional French Onion Soup

A traditional French onion soup will have slices of baguette layered on top of the soup. Baked into the baguette you’ll also find a heavy layer of cheese.

This aspect gives the soup a larger array of textures and acts as an inviting way to soak up the liquid.

If you don’t like baguettes you can remove this part of the meal, as the main aspect of a French onion soup is the soup itself.

The Secret To A Perfect Traditional French Onion Soup

Ingredients

  • Onions – 1.3 kg
  • Beef Stock – 7 to 8 cups
  • Baguette – ½ (Sliced)
  • Gruyere Cheese – 1.5 cups (shredded)
  • White Wine – ½ cup
  • Flour – 2 tablespoons
  • Unsalted Butter – 3 tablespoons
  • Worcestershire Sauce – 1 tablespoon
  • Garlic – 1 tablespoon (minced)
  • Bay Leaf – 2
  • Thyme – 3 sprigs
  • Salt – to taste
  • Pepper – to taste
  • Oil – 2 tablespoons

Onions

It doesn’t matter if you pick yellow, white, or red onions. Any of the three will work well. Some chefs suggest having a mixture of the three, as it can add a unique visual as well as a different flavor in each “bite”.

For a truly traditional French onion soup, you should choose yellow onions. These onions have a spicier flavor and a lot of sugar.

That sweetness is what we’re after, as we need it to balance the rich beef stock tones. If you don’t like a sweet French onion soup, then swap it for white onions instead.

Stock

We have mentioned the importance of stock multiple times now. Buy good quality beef. If you can’t find beef, choose chicken. Either way, make sure you choose a stock with rich and deep flavors.

Baguette

When you first see a French onion soup, you’ll notice the cheese first and then the baguette. The baguette needs to have a soft interior to soak up the soup, but a crisp crust to give the meal added textures.

Cheese

The cheese on top of the soup should start to melt very quickly. This means you’ll need a soft cheese which is ideally grated.

We believe that gruyere is the best option, but mozzarella would also do nicely.

Wine

Adding wine to the mixture means adding acidity. This prevents the soup from sticking to the bottom of the pan. In all honesty, you can forgo the wine, but this could ruin your pan or create a massive clean-up project.

The alcohol will be burned off through the cooking process.

Butter

The butter is only used in the caramelization process. You can use salted butter but it isn’t necessary. Pick the butter you have at hand.

You can also forgo the butter and choose oil instead, however, the flavors will be damped.

Salt And Pepper

The Worcestershire sauce and the stock will both add salt to your meal, you don’t need to add any more. If you choose a yellow onion, you will also have all the spice you need.

However, everyone has their own preferences, so at the end of the cooking process taste-test the soup and decide if more is needed.

The Secret To A Perfect Traditional French Onion Soup

Method

Step 1

Peel and slice the onions. Ideally, they should look like an inch-long strand.

Step 2

Add the oil and butter to a wide pot. Start heating the butter combination until you can see bubbles form.

Step 3

Gently place the onions into the butter combination, making sure not to burn yourself. Cover the pot and allow the onions to cook for 10 minutes undisturbed.

When the 10 minutes are up, stir the mixture, and then recover for another 10 minutes.

Step 4

When the 20 minutes pass, the onions will be soft. You’ll notice the pan has browned – this is normal. Lower the heat.

Check if the onions need more oil or butter, and then continue cooking and cover for another 30 minutes. Make sure to stir the onions every 5 minutes, so they don’t burn or stick to the pan.

We want the onions to be a dark brown color, as this will give us the sweetness we are after.

TipThe onions will burn quickly in the last 10 minutes. Keep an eye on them and remove them from the heat if they turn from caramelized to burnt.

Step 5

Just before you’re ready to move the onions from the heat, add in the minced garlic, minced thyme, bay leaf, and pepper. Cook for 1 minute, and then add the white wine.

The wine will remove the brown parts stuck to the pot, allowing more of the detailed flavors to stay in the soup.

Step 6

Increase the temperature, and stir the mixture until the wine is reduced by half.

The Secret To A Perfect Traditional French Onion Soup

Step 7

Reduce the heat again, and sieve in the flour. Mix the ingredients together so the flour isn’t detectable.

Add in the broth and continue to mix until the liquid reaches a simmer. Cover and allow to simmer for 10 minutes.

Step 8

Start this process 15 minutes before serving. Heat your oven to 200 degrees Celsius or 350 degrees Fahrenheit.

While it’s heating, cut your baguette into 2-inch slices. Butter both sides of the bread, lay them on the baking tray, and cook for 5 minutes or until it has turned golden brown.

Step 9

Remove the baguette slices from the oven, lay the shredded cheese on top, and put them back into the oven for another 2 minutes or until the cheese melts.

Step 10

Transfer the soup into bowls, and delicately place the baked baguette on top. Ideally, the bowls should be small so the baguette doesn’t sink to the bottom.

The Secret To A Perfect Traditional French Onion Soup

Long Term Storage Which Keeps The Flavor

Ideally, the baked bread should be cooked 10 minutes or so before you serve the soup. You cannot store it effectively, so only bake enough bread to serve that day.

However, the soup can easily be frozen. You could make a large batch, serve some to you and your family, and then put the rest in Tupperware containers and throw them in the freezer.

We highly recommend using a tight sealing container, so the soup doesn’t leak through the lid.

Another tip is to cover the container with tin foil. This acts as a double-layered insulation, allowing you to put the soup into the freeze straight away, instead of waiting for it to cool.

The double layer makes the freezing process slower, preventing breakages or a shock to the soup.

If you don’t want to freeze the soup, you can leave it for up to 4 days in the refrigerator.

When you’re ready for another serving, simply reheat it in the microwave until it’s piping hot. If you’re serving bread with soup, you could cook them both in the oven.

To really enjoy the flavor, you shouldn’t eat the soup straight away. The soup tastes better when you leave it for a day. This is because the ingredients settle and release more flavors as they relax.

Soup and stews taste better on the second day than on the first, so if you have the storage, prepare the soup a day ahead of schedule and serve it at its peak.

How To Make A Vegetarian Version

The most important ingredient in a French onion soup is beef stock. There is no going around it. Beef makes this dish delicious. So to make a vegetarian version, we need a flavor that matches the depth and intensity of beef.

A lot of recipe creators will suggest replacing the beef stock with a vegetable broth, but that won’t cut it.

Instead, you should use a mushroom broth. Mushroom broth is hard to come by, but it’s the only vegetable broth that comes close to beef. It has a rich, deep, and meaty texture.

To really drive the richness home, you should replace the white wine with red. It adds to the darkness we lack from missing the beef.

If you are against using alcohol, then try soy sauce instead. It will have the same richness but will not help to unstick the pan.

How To Make Mushroom Stock

Mushroom stock is hard to come by, but we don’t want vegetarians missing out on this rich flavor simply because their local stores don’t have the ingredients they need. Instead make your own.

This recipe will make 8 cups of mushroom stock.

Ingredients

  • Oil – 2 teaspoons
  • Carrots – 2
  • Onion – 1
  • Tomato Puree – 1 teaspoon
  • Button Mushrooms – 1/2 lb
  • Fried Shiitake Mushrooms – 1 oz
  • Garlic – 3 cloves
  • Thyme – 3 sprigs
  • Bay Leave – 2
  • Salt – 1 teaspoon
  • Black Peppercorn – 4
  • Water – 6 cups

Method

Step 1

In a large pot, heat the oil and then add the chopped onions and carrots. Cover the pot, increase to high heat, and cook for 5 minutes or until the onions start to brown.

If the carrots don’t brown, we will be left with a sweet stock which is the opposite of what we want.

Step 2

Add in the tomato puree and cook for 2 minutes or until caramelized.

Step 3

Add in the rest of the ingredients, and wait for the water to start simmering. Then reduce the heat and allow it to simmer for 30 minutes.

Make sure to remove the scum that will appear.

Step 4

Using a large bowl, cover the top with a mesh sieve. Pour your newly made stock into the bowl through the sieve. The sieve will collect the solids, and allow the liquid to be contained.

Discard the solids and put the liquid stock back into the pan.

Step 5

Simmer the stock for another 15 minutes. This will help the liquid to intensify the flavors.

Step 6

Either use immediately or pour the liquid into airtight containers. Store in the freezer for 3 months or in the refrigerator for 5 days.

The History Of The French Onion Soup

As you can guess from the name, French onion soups come from France. It was first documented in a 14th-century book called Viandier. However, there are other accounts throughout history using this soup.

The most commonly known literary comment about the soup was its ability to mask the scent of alcohol.

The French onion soup was mostly used as a hangover cure, and an ingenious method to hide your nightly events from your employers.

Onion soups are very common in European countries. They could be grown in large amounts, withstand bad harvest seasons, and can be cooked with just water – no other ingredients.

This made onion soup a classic meal for most countries, but because of this, it was considered poverty food.

The change from nose up in social hierarchy disgust, to nose down to enjoy the delicious meal came from King Louis XV.

The story goes that King Louis XV was hunting in his lodge, and became hungry. The lodge wasn’t prepared for his impromptu visit, so all he had was onions, butter, and champagne.

He enjoyed his own creation so much, then he asked his chefs to adapt the lodge soup into something refined enough for his status.

They added beef stock – a very expensive ingredient in those days – and hey presto the French onion soup was born!

Final Thoughts

French onion soup has two main ingredients – beef stock and caramelized onions.

If you’re vegetarian you can swap the beef stock for mushroom stock, but make sure to add more depth by including red wine or soy sauce.

The recipe takes a long time to complete despite its deceptively simple name, but in the end, you’ll be left with a rich and moreish soup you will be proud of.

Frequently Asked Questions

What Is The Difference Between Onion Soup And French Onion Soup?

The main difference between onion soup and French onion soup is the use of stock and the use of onions.

Regular onion soup emphasizes onions, using as many different varieties as possible. It also uses chicken stock to allow the onion flavor to take the president.

French onion soup focuses on the beef stock more than anything else, while the caramelized onion adds a visual addition as well as a sweet addition.

If you want a rich and warming soup choose French onion, if you want a spicy and sharp soup choose regular onion soup.

How Do You Deepen The Flavor Or French Onion Soup?

If you cannot find a good quality beef stock, you can deepen the flavor of your soup by increasing the Worcestershire sauce ingredients.

Worcestershire sauce has a strong and rich flavor. In our recipe above we only use 1 tablespoon of the stuff, as we only want it to bind our already strong flavors.

However, if your beef stock is weak, adding more Worcestershire sauce can increase the beef strength.

The downside is the Worcestershire sauce will overpower the beef flavors. This is worth it if your beef flavors are weak, but can make the soup taste bitter if your flavors are already well-balanced.

Does It Matter How You Cut Onions For French Onion Soup?

Ideally, the onions should be about ¼ inch thick and sliced lengthwise. This will create a strand-like texture for a beautiful visual. If you’re unsure about the sizing, it’s better to cut it too thick than too thin.

If it’s too thin it may caramelize quicker, making the balance between caramelization and burning harder to master. However it’s too thick (for example just cutting the onion in half), it simply won’t caramelize.

Make strips around ¼ inch wide, and the full length long.

The Secret To A Perfect Traditional French Onion Soup

Recipe by Lana RiveraCourse: Uncategorized
Servings

4

servings
Prep time

30

minutes
Cooking time

40

minutes
Calories

300

kcal

Ingredients

  • Traditional French Onion Soup
  • Onions – 1.3 kg

  • Beef Stock – 7 to 8 cups

  • Baguette – ½ (Sliced)

  • Gruyere Cheese – 1.5 cups (shredded)

  • White Wine – ½ cup

  • Flour – 2 tablespoons

  • Unsalted Butter – 3 tablespoons

  • Worcestershire Sauce – 1 tablespoon

  • Garlic – 1 tablespoon (minced)

  • Bay Leaf – 2

  • Thyme – 3 sprigs

  • Salt – to taste

  • Pepper – to taste

  • Oil – 2 tablespoons


  • Mushroom Stock
  • Oil – 2 teaspoons

  • Carrots – 2

  • Onion – 1

  • Tomato Puree – 1 teaspoon

  • Button Mushrooms – 1/2 lb

  • Fried Shiitake Mushrooms – 1 oz

  • Garlic – 3 cloves

  • Thyme – 3 sprigs

  • Bay Leave – 2

  • Salt – 1 teaspoon

  • Black Peppercorn – 4

  • Water – 6 cups

Directions

  • Traditional French Onion Soup
  • Peel and slice the onions. Ideally, they should look like an inch-long strand.
  • Add the oil and butter to a wide pot. Start heating the butter combination until you can see bubbles form.
  • Gently place the onions into the butter combination, making sure not to burn yourself. Cover the pot and allow the onions to cook for 10 minutes undisturbed.

    When the 10 minutes are up, stir the mixture, and then recover for another 10 minutes.
  • When the 20 minutes pass, the onions will be soft. You’ll notice the pan has browned – this is normal. Lower the heat.

    Check if the onions need more oil or butter, and then continue cooking and cover for another 30 minutes. Make sure to stir the onions every 5 minutes, so they don’t burn or stick to the pan.

    We want the onions to be a dark brown color, as this will give us the sweetness we are after.
  • Just before you’re ready to move the onions from the heat, add in the minced garlic, minced thyme, bay leaf, and pepper. Cook for 1 minute, and then add the white wine.

    The wine will remove the brown parts stuck to the pot, allowing more of the detailed flavors to stay in the soup.
  • Increase the temperature, and stir the mixture until the wine is reduced by half.
  • Reduce the heat again, and sieve in the flour. Mix the ingredients together so the flour isn’t detectable.

    Add in the broth and continue to mix until the liquid reaches a simmer. Cover and allow to simmer for 10 minutes.
  • Start this process 15 minutes before serving. Heat your oven to 200 degrees Celsius or 350 degrees Fahrenheit.

    While it’s heating, cut your baguette into 2-inch slices. Butter both sides of the bread, lay them on the baking tray, and cook for 5 minutes or until it has turned golden brown.
  • Remove the baguette slices from the oven, lay the shredded cheese on top, and put them back into the oven for another 2 minutes or until the cheese melts.
  • Transfer the soup into bowls, and delicately place the baked baguette on top. Ideally, the bowls should be small so the baguette doesn’t sink to the bottom.

  • Mushroom Stock
  • In a large pot, heat the oil and then add the chopped onions and carrots. Cover the pot, increase to high heat, and cook for 5 minutes or until the onions start to brown.

    If the carrots don’t brown, we will be left with a sweet stock which is the opposite of what we want.
  • Add in the tomato puree and cook for 2 minutes or until caramelized.
  • Add in the rest of the ingredients, and wait for the water to start simmering. Then reduce the heat and allow it to simmer for 30 minutes.

    Make sure to remove the scum that will appear.
  • Using a large bowl, cover the top with a mesh sieve. Pour your newly made stock into the bowl through the sieve. The sieve will collect the solids, and allow the liquid to be contained.

    Discard the solids and put the liquid stock back into the pan.
  • Simmer the stock for another 15 minutes. This will help the liquid to intensify the flavors.
  • Either use immediately or pour the liquid into airtight containers. Store in the freezer for 3 months or in the refrigerator for 5 days.
Lana Rivera
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