Is King Arthur gluten free flour truly gluten-free?

November 25, 2025 •

4 min read

Over 3 million people in the United States have celiac disease, driving a significant market for specialized food products. While King Arthur's gluten-free flours are popular, the question remains: is King Arthur gluten free flour truly gluten-free for everyone, especially those with varying sensitivities or wheat allergies?

Quick Summary

This article examines the different King Arthur gluten-free flour options, clarifying which products are certified gluten-free and suitable for those with celiac disease. It also differentiates between the gluten-free flours that are safe for celiac patients and those that contain wheat starch and are therefore unsafe for individuals with a wheat allergy. The article also provides a comparison table of different products.

Key Points

Certification Matters: Most King Arthur gluten-free flours, including 'Measure for Measure' and 'All-Purpose', are certified by GFCO, a third-party organization with stringent testing for less than 10ppm gluten.
Wheat Starch is a Factor: King Arthur's 'Gluten-Free Bread Flour' and 'Pizza Flour' contain wheat starch, which is treated to remove gluten. While safe for most with celiac disease, it's unsafe for those with a wheat allergy.
Know Your Sensitivity: For individuals with a wheat allergy, any product containing wheat starch should be avoided completely, as the label 'gluten-free' does not mean 'wheat-free'.
Not All Products Are the Same: Always read the ingredient list and look for the 'Certified Gluten-Free' badge on the packaging, as different King Arthur gluten-free products use different formulations.
Safety Measures are in Place: King Arthur has strict cleaning and testing protocols for their certified products to prevent cross-contamination, ensuring product safety.
Texture vs. Allergy: The wheat starch in some flours is added to improve texture in yeasted recipes, but it requires consumers to make an informed choice based on their specific dietary needs.

Understanding 'Gluten-Free' and King Arthur's Product Range

Navigating the world of gluten-free baking requires careful attention to labeling, ingredients, and processing methods. King Arthur Baking Company, a long-standing and trusted name in the baking industry, offers a range of gluten-free products. However, the blanket term 'gluten-free' can be misleading, as King Arthur offers different products that cater to slightly different needs. The crucial difference lies in the use of specialized ingredients and the level of gluten testing and certification. This section breaks down what 'gluten-free' means in general and how King Arthur's products align with this definition. The key takeaway is that the safety of the product depends on the specific type of King Arthur gluten-free flour you purchase.

The All-Purpose and Measure for Measure Flours

King Arthur's Gluten-Free All-Purpose Flour and Measure for Measure Flour are a staple for many gluten-free bakers. These products are formulated with a blend of non-wheat ingredients, such as rice flour, tapioca starch, potato starch, and sorghum flour. Crucially, both are certified gluten-free by the Gluten-Free Certification Organization (GFCO), which mandates products test below 10 parts per million (ppm) of gluten, a standard more stringent than the FDA's requirement of less than 20 ppm. These products do not contain wheat ingredients, making them safe for both individuals with celiac disease and those with a wheat allergy.

The Gluten-Free Bread Flour and Pizza Flour

Where the distinction becomes critical is with King Arthur's Gluten-Free Bread Flour and Pizza Flour. These products contain gluten-free wheat starch. The wheat starch is processed to remove the gluten protein, and the final product is tested to ensure it meets the gluten-free standard of less than 20 ppm (with a target of under 10 ppm). While this makes it safe for most individuals with celiac disease, it is not suitable for anyone with a wheat allergy. The presence of wheat, even in starch form, can trigger an allergic reaction. This is a common point of confusion and is clearly stated on the packaging, but often overlooked by consumers.

How King Arthur Prevents Cross-Contamination

For those relying on certified gluten-free products, cross-contamination is a significant concern. King Arthur Baking Company addresses this by following stringent protocols in their manufacturing facilities for certified products.

Clean-out Procedures: Production lines undergo thorough cleaning between runs of products containing allergens.
Dedicated Equipment: Some certified gluten-free products are produced on dedicated equipment to minimize risk.
Allergen Testing: Regular testing is performed on equipment and finished products to ensure cleanliness specifications are met and gluten levels are below the certified threshold.

Comparison: King Arthur Certified vs. Wheat Starch Flours

Making an Informed Choice

Making the right choice depends entirely on your specific dietary needs. For the average consumer following a gluten-free diet, both product lines are safe and delicious options. The certified blends, free of wheat starch, offer a worry-free experience for a broad range of baked goods. The bread and pizza flours, while containing wheat starch, provide a texture and flavor closer to traditional wheat flour that is often preferred for yeasted recipes.

However, for individuals with a wheat allergy, any product containing wheat starch, regardless of gluten content, must be avoided. It's crucial to read the ingredient list carefully, rather than relying solely on the 'gluten-free' label. For these individuals, the Measure for Measure or All-Purpose blends are the appropriate choice.

Conclusion: Read the Label Carefully

The core answer to whether King Arthur gluten free flour is truly gluten-free is a qualified 'yes,' but with a critical distinction based on the specific product. For those with celiac disease, the certified products are safe due to rigorous testing and processing standards, even if some (like the bread flour) contain specially-processed wheat starch. Conversely, anyone with a true wheat allergy must avoid the bread and pizza flours, opting instead for the wheat-free, certified gluten-free options like the Measure for Measure blend. Always check the ingredient list and product packaging for the Certified Gluten-Free label to ensure it aligns with your specific dietary restrictions.

King Arthur's Allergen Program provides detailed information on their manufacturing processes and testing for certified products.

Frequently Asked Questions

King Arthur's Gluten-Free All-Purpose Flour and Measure for Measure Flour are wheat-free and certified gluten-free, making them safe for individuals with a wheat allergy.

Yes, for most people with celiac disease. The flour contains gluten-free wheat starch that has been processed and tested to meet or exceed FDA gluten-free standards (below 20 ppm).

Gluten-free means the product contains less than 20 ppm of gluten. Wheat-free means it contains no wheat. Products with processed wheat starch can be gluten-free, but not wheat-free.

No. Only the specialized products like the Gluten-Free Bread Flour and Pizza Flour contain processed gluten-free wheat starch. The All-Purpose and Measure for Measure varieties do not.

Look for the 'Certified Gluten-Free' badge from the GFCO on the front of the packaging. These products undergo rigorous third-party testing.

The gluten-free wheat starch is used in yeasted flour products to provide a texture and flavor profile that more closely mimics traditional wheat-based baked goods.

King Arthur follows strict cleaning, equipment testing, and allergen protocols for their certified gluten-free products to minimize the risk of cross-contamination.