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Is sweet and sour sauce from the Chinese gluten free?

Sweet and sour sauce is a popular condiment served with Chinese food like sweet and sour chicken or sweet and sour pork. It has a sweet, tangy and sour flavor that perfectly complements the crispy batter coating on chicken, pork, shrimp and vegetables. But for people with gluten intolerance or celiac disease, enjoying this tasty sauce may be difficult due to potential sources of gluten used to thicken the sauce. So is sweet and sour sauce really gluten free? Let’s take a closer look.

What is gluten and why must some people avoid it?

Gluten is a general name for the proteins found in wheat, rye and barley. It helps give elasticity to dough, which is why it’s so commonly used in baked goods. For most people, consuming gluten is not a problem. But for those with celiac disease or non-celiac gluten sensitivity, gluten triggers an abnormal immune response that damages the small intestine. Even small amounts of gluten can cause issues for these individuals.

Celiac disease is an inherited autoimmune disorder that affects nearly 1% of the population. When someone with celiac disease eats gluten, their immune system responds by attacking the small intestine, leading to damage of the villi – small, finger-like projections that line the intestine and absorb nutrients. This can cause symptoms like diarrhea, abdominal pain, bloating, weight loss, fatigue and anemia. Non-celiac gluten sensitivity causes similar gastrointestinal symptoms but without the autoimmune attack on the intestine.

The only treatment for celiac disease or non-celiac gluten sensitivity is strict adherence to a gluten-free diet. This means avoiding foods and ingredients containing wheat, rye, barley and often oats (which are often cross-contaminated with gluten). Even tiny amounts of gluten from cross-contamination can trigger symptoms and intestinal damage.

Common sources of gluten in restaurant sauces

Gluten can sneak into restaurant sauces through common thickening agents:

Wheat flour

Wheat flour contains gluten and is often used as a thickener in gravies and sauces. Just 1 tbsp of wheat flour contains about 8 grams of gluten.

Soy sauce

Many soy sauces contain wheat. Gluten-free tamari can be substituted.


Starches made from wheat, like wheat starch, are not gluten-free. Corn starch or arrowroot starch are good substitutes.

Hydrolyzed wheat protein

This wheat-derived additive boosts flavor. It contains gluten.

Malt vinegar

Vinegars made from barley malt contain gluten. Cider or white wine vinegar are gluten-free alternatives.

Thickening agents

Many thickening agents and stabilizers contain gluten, including gums like wheat dextrin.

So sweet and sour sauce could easily pick up traces of gluten during preparation at a restaurant. But that doesn’t necessarily mean it’s off limits. Let’s explore some tips for ordering it gluten-free.

Tips for ordering gluten-free sweet and sour sauce

Here are some ways to enjoy sweet and sour sauce while avoiding the gluten:

Ask about the ingredients

Don’t be afraid to ask your server for details on how the sweet and sour sauce is prepared. Inquire about potential sources of gluten like soy sauce and thickeners used. A well-informed server should be able to tell you if it’s thickened with wheat-free ingredients.

Request gluten-free soy sauce

Ask if they have tamari or a gluten-free soy sauce alternative that can be used in the sauce. This simple swap can make it gluten-free.

Get it on the side

Requesting sweet and sour sauce on the side reduces the risk of cross-contamination from food prepared in the same fryer.

Avoid battered ingredients

Battered proteins like sweet and sour chicken may be dusted with wheat flour. Request plain chicken or shrimp instead.

Try a different sauce

Many Chinese restaurants offer gluten-free homemade sauces like garlic sauce, brown sauce, plum sauce and hot mustard. Ask for one of these instead just to be safe.

Check for certification

Some Chinese restaurants advertise gluten-free menus and prep areas. Look for a gluten-free certification from organizations like the Gluten Intolerance Group when possible.

Do your research

Search for restaurant reviews mentioning gluten-free options. Call ahead to ask questions about menu items and preparation. Being an informed diner is key for gluten-free dining.

Homemade sweet and sour sauce recipe

Making sweet and sour sauce at home lets you control the ingredients. This recipe is naturally gluten-free:


  • 1/2 cup pineapple juice
  • 1/3 cup white vinegar
  • 1/4 cup ketchup
  • 3 tbsp brown sugar
  • 2 tbsp tamari or soy sauce
  • 1 clove garlic, minced
  • 1 tsp grated fresh ginger
  • 2 tsp corn starch
  • 1/4 tsp red pepper flakes (optional)


  1. In a small saucepan, whisk together all ingredients except corn starch.
  2. Bring to a boil over medium-high heat, then reduce heat and simmer for 5 minutes.
  3. Mix corn starch with 1 tbsp water. Slowly stir into sauce to thicken.
  4. Remove from heat. Serve hot over chicken, pork or shrimp.

This homemade version uses corn starch to thicken without gluten. Enjoy it as a dipping sauce or drizzle it over a gluten-free stir fry.

The verdict on sweet and sour sauce

Sweet and sour sauce may or may not be gluten-free at a restaurant, depending on how it’s prepared. Many eateries use thickening agents or soy sauce containing gluten. But with a few modifications like requesting gluten-free soy sauce, or asking for it on the side, you may be able to enjoy this tasty condiment. Opting for a naturally gluten-free homemade recipe is the safest option for gluten-free eaters. When in doubt at a restaurant, asking questions and doing your homework is key to avoiding the hidden gluten in sauces.

Thickener Contains Gluten?
Wheat Flour Yes
Soy Sauce Sometimes
Wheat Starch Yes
Corn Starch No
Hydrolyzed Wheat Protein Yes
Barley Malt Vinegar Yes

Key Takeaways

  • Sweet and sour sauce may contain gluten from soy sauce, wheat flour or other thickeners.
  • Ask about ingredients, request gluten-free soy sauce and get it on the side to reduce contamination risk.
  • Making it at home with corn starch lets you control the ingredients.
  • When dining out, research and ask questions to assess potential gluten sources in sauces.


Sweet and sour sauce can be tricky for the gluten-free diet due to potential sources of gluten used in restaurant preparations. But by asking questions, making modifications and doing your homework, you may be able to enjoy this bright, flavorful sauce. Making it yourself at home offers the greatest control over ingredients. With some care and awareness, sweet and sour sauce can still have a place in your gluten-free diet.