Is Mustard Really Gluten-Free?

Eating a hot dog without mustard is a little like washing your hair without shampoo — it's an essential part of the process.

But if you're living with celiac disease or gluten sensitivity, you have to be picky about all the ingredients you add to your lunch. Luckily, most plain mustard is gluten-free and safe to slather onto your favorite foods — just be sure to check the packaging before you buy.

Gluten is a protein found in wheat, rye and barley and these grains' derivatives. In its simplest form, mustard is generally gluten-free. But there are some caveats.

Unlike single-ingredient foods, there are plenty of mustard varieties, including dijon, yellow mustard, honey mustard and beer mustard. Some of these versions may be free of wheat, rye or barley ingredients (making them gluten-free) but there's no guarantee, according to the Celiac Disease Foundation.

Most plain mustard is made with just mustard seed, vinegar, turmeric, salt and spices, according to the USDA. For the most part, these ingredients are gluten-free and safe for individuals with gluten sensitivity.

But recipes vary depending on the brand or added ingredients. Today, there's no shortage of creative flavors out there, which can include gluten ingredients like malt vinegar — a form of barley, which contains gluten, per the Celiac Disease Foundation.

Even if the mustard you're buying contains no gluten on the label, it may still be at risk for cross-contamination, which occurs when gluten foods come in contact with other ingredients either through manufacturing or preparation, according to the Celiac Disease Foundation.

Cross-contact is probably the biggest concern you should have when it comes to mustard. When mustard is contaminated, it can become a risk for those with gluten intolerance. But you can prevent this issue by choosing your condiments carefully.

Avoid ordering mustard at a restaurant that's served in little bowls or cups (unless the location is Certified Gluten-Free). Here's why: Wheat flour in a restaurant can get into the air, causing it to settle on surfaces or foods in the kitchen, also known as airborne gluten, according to the National Celiac Association.

To be safe, ask for mustard packets instead. That way, you can squeeze them yourself without any cause for concern.

At the supermarket, find a "Gluten-Free" label on the front package of the product.

This label is regulated by the Food & Drug Administration and signifies that the food you're eating has less than 20 parts per million (ppm) of gluten, which is generally safe for people with celiac to eat.

If you want even more security, buy foods that are labeled "Certified Gluten-Free" and are vetted by trusted third parties, including the Gluten-Free Certification Organization (GFCO). The GFCO has especially strict standards, certifying foods that have only 10 ppm of gluten or less, according to the organization's website.

If your chosen product doesn't contain either of these labels, read the ingredient list and look out for any gluten-based ingredients, and check the allergen statement for wheat or gluten, too.

If the mustard doesn't contain gluten per the ingredient list and allergen statement, it might be safe, but there's no guarantee as cross-contact could have occurred in the manufacturing facility.