Name: Subway Sweet Onion Sauce Recipe: Make It at Home!
Prep time: 5 min
Cook time: 10 min
Total time: 15 min
Cuisine: American
Ingredients: 1 cup sugar; 1/2 cup water; 6 tablespoons white vinegar; 1 1/2 tablespoons red wine vinegar; 1/2 tablespoon finely minced onion; 1 tablespoon cornstarch; 2 teaspoons Dijon mustard; 2 teaspoons mustard powder; 1 teaspoon poppy seeds; 1/2 teaspoon sesame oil; 1/2 teaspoon onion powder; 1/2 teaspoon salt; 1/4 teaspoon garlic powder; 1/4 teaspoon celery seed; 1/4 teaspoon paprika; 1/4 teaspoon black pepper

Jump to Recipe·Print Recipe

Have you ever wondered how to recreate the famous Subway Sweet Onion Sauce at home? That delicious, tangy, and slightly sweet sauce elevates every sandwich with its bold flavor and perfect balance of sweetness and spice. Now, you don’t have to rely on takeout—you can make this sauce from scratch with simple pantry ingredients!

Whether you love drizzling it over subs, wraps, salads, or even grilled meats, this homemade sweet onion sauce will become a staple in your kitchen. Let’s dive into the perfect copycat recipe so you can enjoy the magic of this sauce anytime!

Why You’ll Love This Homemade Sweet Onion Sauce

Tastes Just Like Subway’s – A perfect match to the original flavor.
Made with Simple Ingredients – No preservatives or additives.
Versatile & Delicious – Use it on sandwiches, salads, meats, and more.
Quick & Easy – Ready in just 15 minutes!

Ingredients for Subway Sweet Onion Sauce Recipe

To make the perfect homemade sweet onion sauce, you’ll need a mix of sweet, tangy, and savory flavors.

Main Ingredients

Ingredient	Amount
Sugar	1 cup
Water	1/2 cup
White vinegar	6 tbsp
Red wine vinegar	1 1/2 tbsp
Finely minced onion	1/2 tbsp
Cornstarch	1 tbsp
Dijon mustard	2 tsp
Mustard powder	2 tsp
Poppy seeds	1 tsp
Sesame oil	1/2 tsp
Onion powder	1/2 tsp
Salt	1/2 tsp
Garlic powder	1/4 tsp
Celery seed	1/4 tsp
Paprika	1/4 tsp
Black pepper	1/4 tsp

Step-by-Step Instructions

1. Prepare the Ingredients

Finely mince the onion for a smooth texture.
Gather all spices and seasonings to ensure easy cooking.

2. Make the Base Mixture

In a saucepan, combine sugar, water, white vinegar, and red wine vinegar.
Stir well over medium heat until the sugar dissolves completely.

3. Add the Flavor Enhancers

Stir in minced onion, Dijon mustard, mustard powder, and sesame oil.
Mix until the ingredients are well incorporated.

4. Thicken the Sauce

In a small bowl, mix cornstarch with a tablespoon of water to create a slurry.
Slowly add the slurry to the saucepan while stirring constantly.
Cook for 3-5 minutes, stirring, until the sauce thickens slightly.

5. Season & Simmer

Add poppy seeds, onion powder, garlic powder, celery seed, paprika, salt, and black pepper.
Reduce the heat and simmer for another 2-3 minutes, stirring occasionally.

6. Cool & Store

Remove from heat and let the sauce cool completely.
Transfer to an airtight container and refrigerate for at least 1 hour before using.

Pro Tips for the Best Sweet Onion Sauce

1. Adjust the Sweetness

For a less sweet version, reduce sugar to 3/4 cup.
Add a touch of honey for a more natural sweetness.

2. Control the Thickness

If the sauce is too thin, add a little more cornstarch slurry.
For a thinner consistency, stir in 1-2 tablespoons of water.

3. Enhance the Onion Flavor

Use freshly minced onions for a more intense onion kick.
Try caramelized onions for added depth.

How to Use Subway Sweet Onion Sauce

This homemade sweet onion sauce is incredibly versatile! Here are some delicious ways to enjoy it:

Sandwiches & Wraps – Drizzle over subs, grilled chicken wraps, or turkey sandwiches.
Salads – A perfect topping for chicken or veggie salads.
Grilled Meats – Brush over chicken, salmon, or steak for extra flavor.
Dipping Sauce – Pair with French fries, onion rings, or chicken tenders.

Nutritional Information (Per Serving)

Nutrient	Amount
Calories	45
Carbohydrates	12g
Sugar	10g
Fat	0.5g
Protein	0g
Sodium	50mg

Note: Nutritional values are estimates and may vary based on ingredients used.

Variations to Try

1. Spicy Sweet Onion Sauce

Add 1/4 teaspoon cayenne pepper for a spicy kick.
Mix in a few dashes of hot sauce for extra heat.

2. Low-Sugar Version

Replace sugar with monk fruit sweetener or honey.
Reduce sugar to 1/2 cup for a milder sweetness.

3. Gluten-Free Adaptation

Ensure your Dijon mustard is gluten-free.
Use tapioca starch instead of cornstarch.

Frequently Asked Questions (FAQ)

1. How long does homemade sweet onion sauce last?

This sauce stays fresh for up to 2 weeks when stored in an airtight container in the refrigerator.

2. Can I freeze this sauce?

Yes! Freeze in small portions and thaw in the refrigerator before use.

3. Can I use apple cider vinegar instead of red wine vinegar?

Yes, but it may slightly alter the taste. Red wine vinegar gives the best flavor match to Subway’s sauce.

4. How do I make this sauce thicker?

Increase the cornstarch slurry slightly and cook longer for a thicker consistency.

5. Is this sauce vegan-friendly?

Yes! All ingredients are plant-based and vegan-friendly.

6. Can I make a bigger batch?

Absolutely! Just double or triple the ingredients and store in the fridge for longer use.

Final Thoughts & Call to Action

Now that you have the perfect Subway Sweet Onion Sauce Recipe, it’s time to bring the flavors of Subway into your kitchen! With just a few simple ingredients, you can create a delicious, homemade version that’s even better than the original.