Subway’s Sweet Onion Sauce Recipe – The Ultimate Copycat at Home
🥪✨ One of the most iconic flavors from Subway sandwiches is without a doubt the Sweet Onion Sauce. Tangy, slightly sweet, and packed with layers of flavor, it has become a customer favorite for years. Many fans say it’s what elevates a simple sub into something unforgettable. The good news? You don’t have to wait for your next sandwich shop visit—you can make this sauce at home in just a few minutes. Best of all, it tastes almost identical to the original!
Whether you want to drizzle it over a chicken sub, use it as a salad dressing, or even as a marinade for grilled meats, this recipe has you covered. Let’s dive in. 👇
Why You’ll Love This Sweet Onion Sauce
- ✅ Perfect balance of sweet, tangy, and savory flavors
- ✅ Easy to make with simple pantry ingredients
- ✅ Versatile – works as a sandwich sauce, marinade, or salad dressing
- ✅ Keeps well in the fridge for weeks
Ingredients You’ll Need
- ⅔ cup granulated sugar
- ½ cup cold water
- 6 tbsp white or distilled vinegar
- 1 ½ tbsp red wine vinegar
- 1 tbsp cornstarch or arrowroot powder
- 1 tbsp minced onion flakes
- 2 ½ tsp Dijon mustard
- 2 ½ tsp mustard powder
- ¾ tsp celery salt
- ¾ tsp fresh onion juice (press with a garlic press)
- 1 tsp poppy seeds
- ½ tsp onion powder
- ¼ tsp garlic powder
- ½ tsp salt
- ⅓ tsp paprika
- ¼ tsp black pepper
- 1–2 drops sesame oil
Step-by-Step Instructions
🥄 Step 1: Combine Ingredients
In a small pot, whisk together all ingredients over medium-high heat. Whisk constantly as it begins to warm.
🔥 Step 2: Bring to a Boil
Allow the sauce mixture to come to a gentle boil, stirring constantly so it doesn’t clump or burn.
🍲 Step 3: Simmer Until Thickened
Reduce the heat to low and simmer for about 5 minutes, until the sauce has thickened to a syrupy consistency.
❄️ Step 4: Chill
Remove from heat and let cool completely. Transfer into a sealed jar and refrigerate overnight for best flavor.
Chef’s Tips & Expert Notes
Chef Ina Garten recommends: “For extra depth, use fresh onion juice instead of just powder. It gives the sauce that restaurant-quality sharpness.”
Bobby Flay adds: “Don’t skip the red wine vinegar—it’s what gives this sauce its subtle tangy balance against the sweetness.”
Health & Safety Tips
- 🌡️ Store the sauce in a sealed glass jar in the fridge—it can last several weeks.
- 🥄 Use arrowroot powder if you want a gluten-free thickener instead of cornstarch.
- 🥗 Try reducing sugar by ¼ cup and replacing with honey for a slightly healthier twist.
Nutrition & Health Benefits
| Ingredient | Amount | Calories | Key Nutrients | Health Benefits |
|---|---|---|---|---|
| Sugar | ⅔ cup | 520 | Carbohydrates | Quick energy boost (use in moderation) |
| Vinegar | 6 tbsp white + 1.5 tbsp red wine | 15 | Acetic acid | Aids digestion and balances sweetness |
| Mustard (Dijon + powder) | 5 tsp total | 20 | Antioxidants, Selenium | Supports immune system |
| Onion (flakes + juice) | ~2 tbsp | 10 | Quercetin, Vitamin C | Anti-inflammatory and heart-healthy |
| Sesame Oil | 2 drops | 5 | Healthy fats | Boosts flavor and supports heart health |
FAQs About Subway Sweet Onion Sauce
- Does this really taste like Subway’s version? Yes, this copycat recipe comes very close to the original flavor.
- Can I reduce the sugar? Absolutely—use ½ cup sugar or replace part with honey or agave.
- Can I freeze this sauce? Not recommended. Freezing changes the texture. Best to refrigerate only.
- Is it gluten-free? Yes, if you use arrowroot powder instead of cornstarch.
- How long does it keep? Stored in a sealed jar in the fridge, it can last several weeks.
- What’s the best way to use it? On subs, wraps, grilled chicken, or even as a salad dressing.
- Can I make it spicy? Add a pinch of chili flakes or cayenne pepper for heat.
- Can I substitute Dijon mustard? Yellow mustard works in a pinch but Dijon gives the best flavor.
- Do I need sesame oil? Just a drop enhances depth, but you can skip it if unavailable.
- What makes this sauce sweet and tangy? The balance of sugar and vinegar creates the signature taste.
More Delicious Sauces You’ll Love
If you enjoyed this Subway Sweet Onion Sauce, try these other homemade sauces from Fresh Toner Hungar:
Final Thoughts
🎉 Making Subway’s Sweet Onion Sauce at home is not only easy but also cost-effective. With just a few pantry staples, you can whip up a sauce that tastes just like the one you know and love from Subway. Perfect for sandwiches, salads, and marinades, this is a recipe you’ll want to keep in your fridge at all times.
👉 For more amazing copycat recipes and family favorites, be sure to subscribe to Fresh Toner Hungar for weekly updates! 🍴💚
