Gluten-Free at Costco: The Ultimate 2026 Shopping Guide (80+ Safe Products)

Celiac Safety Glossary

Celiac disease

Celiac disease is a serious autoimmune disorder in which ingesting gluten — a protein found in wheat, barley, and rye — triggers an immune response that damages the small intestine's villi, affecting approximately 1 in 100 people worldwide according to the Celiac Disease Foundation.

Gluten

Gluten is a family of storage proteins (prolamins and glutelins) found naturally in cereal grains like wheat (including varieties like spelt, kamut, and farro), barley, and rye, which acts as a binder to give food elasticity and shape.

Gluten-free certification

Gluten-free certification, such as the GFCO (Gluten-Free Certification Organization) seal, verifies that a product contains fewer than 10 parts per million (ppm) of gluten — stricter than the FDA's 20 ppm threshold for "gluten-free" labeling.

Malt (Barley)

Malt is fermented barley used as a flavoring or sweetener in cereals, chocolates, and beer; it is a major source of hidden gluten that is often overlooked on ingredient lists.

📚Sources & Citations

• •Celiac Disease Foundation — celiac.org — Comprehensive research and patient resources on celiac disease
• •Beyond Celiac — beyondceliac.org — Research-driven celiac disease advocacy and resources
• •GFCO (Gluten-Free Certification Organization) — gfco.org — Certification standards (<10 ppm)
• •FDA Gluten-Free Labeling — fda.gov — Federal regulations for <20 ppm labeling

Content reviewed and fact-checked by our clinical & nutrition team. Last updated July 2026.