What Is Subway Sweet Onion Sauce? Sweet Onion Sauce Review

Subway has lots of amazingly tasty sauces. One of our all-time favorites is the Subway sweet onion sauce. There is nothing better than taking a big bite into your sandwich and experiencing those oh so pleasant sweet and tangy flavors! In this article, we will quickly turn you into a Subway sweet onion sauce expert and break down its flavor, calories, and how to make it at home!

What is Subway sweet onion sauce? Subway sweet onion sauce is a sweet and tangy condiment that has a lovely spicy onion flavor. It has 0 grams of fat and only 30 calories per serving. This is Subway’s most popular sauce and goes amazingly well on sandwiches.

Subway sweet onion sauce is super tasty! It immediately adds a rich sweetness to your sandwich. This sauce is very tangy and has a slightly spicy mustard kick. Best of all, you can enjoy this sauce guilt-free as a single serving only contains 30 calories. Subway sweet onion is actually deceptively strong, and you only need a little bit on your sandwich.

Ingredients In Subway Sweet Onion Sauce

Subway Sweet Onion sauce is made from Vinegar, Dehydrated Onion, Sugar, Salt, Cucumber, Poppy Seed, Spices, Pepper, Onion juice, Corn starch, Celery seed, and Mustard.

The main ingredients are sugar, dehydrated onion, pepper, cucumber juice, celery seed, and mustard. These flavors produce a sweet and tangy flavor with a strong onion flavor and a bit of a spicy mustard kick. Every Subway restaurant uses the same ingredients and recipe to create their sweet onion sauce.

See also: Who Makes McDonald’s BBQ Sauce?

Sweet Onion Sauce From Subway: Macronutrient Breakdown!

Subway sweet onion sauce is actually pretty healthy! A single serving only contains 30 calories, 0 grams of fat, and just 7 grams of sugar. For so few calories, this sauce is absolutely loaded with lots of flavors and is actually very rich. The standard serving size (18 grams) is more than enough to enhance the flavor of your sandwich.

Name Amount
Calories 30
Sodium 75mg
Sugar 7g
Protein 0g
Fat 0g
Carbohydrates 8g

If you are looking for a low calorie sauce which is still full of flavor you can’t go wrong with Subway sweet onion sauce! However, be careful if you are going low carb as a single serving still has 8 grams of carbs!

What Does Subway Sweet Onion Sauce Taste Like?

Subway sweet onion sauce is sweet, tangy, rich, and spicy. It has a pronounced onion flavor with sugary sweetness and a tangy vinegar taste. It also has a mild spicy kick from the addition of peppers and mustard.

If you like sweet and tangy sauces then the Subway sweet onion is for you! It has a little bit of heat but overall is mostly sweet with a pronounced vinegar and onion flavor. You can taste a little bit of mustard which adds an additional layer of complexity. Subway sweet onion sauce tastes amazingly well with chicken sandwiches. The sauce is actually quite rich, and you only need a little bit to satisfy your sweet and tangy flavor cravings!

See also: What Sauces Does Popeyes Have? Ultimate Popeyes Sauce Review!

Does Subway Sell Sweet Onion Sauce?

Subway sweet onion sauce is not for sale. No matter how hard you try Subway will not sell you their sauce. It is only available on sandwiches in a Subway restaurant. Hopefully in the future they will bottle it and sell it!  

Oh no! Subway does not sell any of its sauces and it definitely doesn’t sell its Subway sweet onion sauce. Unlike other fast-food chains, even if you are really nice to the staff and offer to pay, they will still not part with their precious sauce. Subway has an explicit policy where they will not sell their sweet onion sauce. Some diehard fans have traveled to multiple restaurants and faced rejection over and over again!

The restaurant is not focused on selling sauces and has determined that the market is not profitable enough to enter. Maybe in the future, if there is enough demand, the fast-food sandwich chain will start bottling its legendary sweet onion sauce and sell it in supermarkets.

How To Make Subway Sweet Onion Sauce?

Follow this quick and simple recipe to make an incredibly tasty sweet and tangy onion sauce that tastes just like Subway sweet onion sauce:


  • 1 onion
  • 2 garlic cloves
  • 1 cup of water
  • ⅓  cup of sugar
  • 1 tsp balsamic vinegar
  • 1 tsp white vinegar
  • ¼ tsp salt
  • 2 tsp cornflour
  • ½ tsp lemon juice


  1. Peel onion, chop, and blend.
  2. Heat up the pan. Add water, sugar, salt, white vinegar, balsamic vinegar and pepper. Bring to a boil!
  3. Whisk water and cornflour together in a bowl
  4. Add cornflour/water mixture to the pan and cook on medium heat
  5. Take the pan off heat and add lemon juice. Stir and let sauce cool.
  6. Place in the fridge for 4 hours and then serve!

Final Thoughts

Subway sweet onion sauce is very tangy with a lovely sweetness. It has a strong onion and vinegar flavor, and you can also taste pepper, cucumber, and mustard. The sauce is very low in calories (30 calories per serving) and has zero fat! It is made from onion, sugar, vinegar, peppers, cucumber, and mustard. It is a great way to add some extra sweet and tangy flavors to your sandwich. Subway produces this sauce in-house and unfortunately it is not for sale and does not come in packets.

See also: What Sauces Does Carl’s Jr Have?

Subway Sweet Onion Sauce FAQ

What is the sweet onion sauce Subway uses?

Subway makes its sweet onion sauce in-house. This sauce is a combination of vegetables, including onion, peppers, cucumber, and mustard. Subway’s sweet onion sauce is sweet and tangy!

Is Subway sweet onion sauce healthy?

A single serving (18 grams) of Subway sweet onion sauce contains 30 calories, 0 grams of fat and 7 grams of sugar. This is a great sauce if you are on a diet!

Is the sweet onion sauce from Subway vegan?

Subway’s sweet onion sauce is 100% vegan. Subway’s sweet onion sauce is made from  Vinegar, Dehydrated onion, Mustard flour, Poppyseed, Onion juice, Dehydrated red bell pepper, Cucumber juice, Celery seed and Mustard.

See also: What Sauce Does White Castle Have?

Can you buy Subway sweet onion sauce?

Subway sweet onion sauce is not for sale! This sauce is not bottled, and the only way to get it is to order it on your sandwich. Unfortunately, even if you are polite to the staff, Subway won’t part from its precious sweet onion sauce.

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