Is There Flour in Hoisin Sauce? A Complete Guide to Gluten Content

November 27, 2025 •

3 min read

A surprising number of store-bought hoisin sauces use wheat flour as a thickener, making it a critical ingredient to check for those with gluten sensitivity. So, is there flour in hoisin sauce? The answer depends entirely on the brand, with commercial products frequently differing from traditional recipes.

Quick Summary

Many commercial hoisin sauces include wheat flour, either as a direct thickener or via wheat-based soy sauce. Those with gluten sensitivities must carefully read labels to ensure the sauce is safe and to avoid potential cross-contamination.

Key Points

Check Labels: Always read the ingredient list, as many commercial brands contain wheat flour as a thickener.
Traditional vs. Commercial: While authentic recipes don't use flour, mass-produced versions often add it for consistency.
Soy Sauce is a Factor: Standard soy sauce, a common hoisin ingredient, is often fermented with wheat and contains gluten.
Look for Alternatives: Certified gluten-free hoisin sauces are available and typically use safe thickeners like cornstarch or tapioca starch.
Beware of Cross-Contamination: For celiac disease, rely only on products with a certified gluten-free label to ensure safety.
Homemade is an Option: Making hoisin from scratch allows for complete control over ingredients and guarantees it is flour-free.

The Simple Answer: It Depends on the Sauce

For anyone with a gluten allergy or sensitivity, the question, "Is there flour in hoisin sauce?" has a nuanced answer. While traditional, authentic hoisin sauce recipes were often naturally gluten-free, relying on fermented soybeans, modern mass-produced versions found in supermarkets frequently contain wheat flour. The flour is added to achieve the thick, glossy consistency that consumers expect from the condiment.

Commercial Hoisin vs. Traditional Recipes

To understand the difference, it is helpful to look at the ingredients of both types. Traditional hoisin is typically a paste made from fermented soybeans, garlic, chili peppers, sugar, and sometimes sesame. The thickness comes naturally from the bean paste and reduction process. Commercial sauces, however, often contain a list of additional ingredients for flavor, consistency, and preservation. This is where wheat flour is frequently introduced.

Why Is Wheat Flour in Commercial Hoisin?

There are two main reasons commercial hoisin sauce contains flour:

As a Thickener: To cut down on production time and costs, manufacturers use wheat flour as an inexpensive and effective thickening agent. This helps create the desired viscosity without the longer reduction process of traditional methods.
In Soy Sauce: A primary ingredient in most hoisin recipes is soy sauce, which is commonly fermented with wheat. This means even if flour isn't listed separately, the sauce may still contain gluten from the soy sauce component.

How to Identify Gluten on Product Labels

For those on a gluten-free diet, a careful examination of the ingredient list is necessary. Here is what to look for:

Wheat Flour: Explicitly look for "wheat flour" or "fermented wheat flour" listed among the ingredients.
Soy Sauce: If soy sauce is listed, it is a red flag. Unless specified as "tamari" or "gluten-free soy sauce," assume it contains wheat.
Allergen Statements: Many food products in regions like the US are required to highlight major allergens. Look for phrases like "Contains: Wheat" near the ingredient list.
Certified Gluten-Free: The safest bet for someone with celiac disease is to purchase a product with a certified gluten-free label. This guarantees that the product has been tested to meet strict gluten-free standards.

Gluten-Free Alternatives and Thickening Agents

Fortunately, there are many gluten-free alternatives to traditional wheat flour that can achieve a similar texture. When searching for a gluten-free hoisin sauce, you might see these ingredients on the label:

Modified Corn Starch: This is a common and safe alternative used to thicken sauces.
Modified Tapioca Starch: Derived from the cassava plant, this provides an effective, gluten-free way to thicken sauces.
Xanthan Gum: A food additive used as a thickener and stabilizer.

Comparison of Hoisin Sauce Types


Feature	Commercial Hoisin (Non-GF)	Gluten-Free Hoisin (Commercial)	Homemade Hoisin (GF)
Flour Content	Often contains wheat flour.	Explicitly free of wheat flour.	Flour-free by design.
Soy Sauce Base	Likely uses soy sauce containing wheat.	Uses tamari or gluten-free soy sauce.	Uses tamari or gluten-free soy sauce.
Thickening Method	Wheat flour, modified corn starch.	Modified corn starch, tapioca starch.	Natural reduction, cornstarch, or arrowroot powder.
Ingredient Control	Low, pre-determined ingredients.	Moderate, limited to brand's recipe.	High, complete control over ingredients.
Best For	General use, not for those with gluten concerns.	Quick, reliable, and safe gluten-free option.	Ultimate freshness and ingredient control.

Making Your Own Flour-Free Hoisin

If store-bought options are unavailable or you prefer complete control over ingredients, making your own hoisin sauce at home is a simple process. Many recipes use a base of gluten-free soy sauce (tamari), rice vinegar, sweeteners like molasses, and spices to recreate the distinctive flavor. The thickness can be achieved with a cornstarch slurry. For those with celiac disease, this is the safest route to ensure a truly gluten-free product.

Conclusion: Making an Informed Choice

In short, while the fundamental nature of hoisin sauce does not require flour, many commercial products do contain it. This is a critical distinction for anyone on a gluten-free diet. By learning to read ingredient labels and knowing what to look for, you can safely enjoy this versatile and flavorful sauce. When in doubt, opting for a product explicitly labeled gluten-free or making your own from scratch are your best options. For more information on celiac disease and ingredients to avoid, you can consult resources like Beyond Celiac.

Frequently Asked Questions

No, hoisin sauce is not always gluten-free. Many commercial brands use wheat flour as a thickener and wheat-based soy sauce in their recipes, so it is essential to check the ingredient list.

Manufacturers often add wheat flour as a cost-effective and quick way to thicken the sauce to the desired consistency. It is also a source of gluten through the common use of wheat-fermented soy sauce.

Gluten-free hoisin sauces are typically thickened with cornstarch, modified corn or tapioca starch, or other naturally gluten-free agents. In homemade recipes, a cornstarch or arrowroot slurry can be used.

Traditional hoisin sauce is made from fermented soybean paste, garlic, chili peppers, and spices like Chinese five-spice powder. It does not typically contain flour.

To determine if a hoisin sauce is gluten-free, check the label for the 'Certified Gluten-Free' logo. If relying on ingredients, look for wheat listed as an allergen and ensure the soy sauce component is specified as gluten-free or tamari.

For individuals with celiac disease, consuming hoisin sauce that contains wheat can trigger an immune response, causing intestinal damage and other adverse health effects. Strict avoidance of gluten is necessary.

Yes, you can easily make your own hoisin sauce at home using gluten-free soy sauce (tamari), rice vinegar, tahini, and spices. This allows you to have complete control over the ingredients and ensure it is flour-free.