The presence of gluten, the protein found in common cereal grains wheat, barley, rye, and their derivatives, can be problematic even in microscopic quantities for those with gluten-related disorders (celiac disease or non-celiac gluten sensitivity). Though the first step in treating gluten-related disorders is eliminating obvious exposures to gluten, it is also essential to avoid accidental exposure via cross-contact. Cross-contact takes place when foods are prepared on common surfaces or with utensils and cookware that are not thoroughly cleaned after preparing gluten-containing foods. It can happen when cooking or baking at home or also in commercial kitchen spaces, where gluten-containing flours may be airborne and settle on surfaces, utensils, and gluten-free products.
There are steps to take at home when working in a shared kitchen where gluten-containing foods are also being prepared and/or eaten. It is crucial to ensure that other members of the household have a clear understanding of the importance of keeping foods and certain kitchen items gluten-free (see below). When possible, one approach is to create a gluten-free area in the refrigerator and/or the pantry, preferably on a top shelf. When gluten-free ingredients are on the top shelf, it prevents crumbs/pieces of gluten-containing foods from falling onto and potentially cross-contaminating the gluten-free items. It is especially beneficial to have a separate set of any utensils and cookware that will be used strictly for gluten-free cooking and to keep them in an area that is separate from sources potential cross-contamination. Though it is important to consider cross-contamination on all kitchenware, the following cooking equipment should be purchased and stored separately or given extra cleaning attention before preparing a gluten-free meal or snack:
- Wooden Utensils
- Cutting Boards
- Nonstick Pans
- Cast Iron Skillet
- Wooden Rolling Pins
- Food Storage Containers
- Waffle Irons
- Cake Pans & Muffin Tins
- Sink Sponges
There are several kitchen appliances and utensils that require increased caution in regards to cross-contamination. The fact that toasters are virtually impossible to thoroughly clean poses a significant issue for use in a shared household or when traveling. Since it could be inconvenient to have two toasters, another option is to purchase toaster bags. Toaster bags provide a barrier between items placed in the bag and the toaster itself. They can be used for breads, bagels, waffles, and more, and can be purchased online. Additionally, strainers, colanders, and flour sifters easily keep gluten in crevices that are very difficult to clean, posing a significant threat for cross-contamination. It is best to purchase a separate set and to keep them stored away from gluten-containing foods. Similarly, plastic or wooden items as well as those with non-stick coatings may develop grooves from wear and tear that can collect gluten, so it is advisable to consider replacing these items. Muffin tins and cake pans may be tricky to clean and a good solution is to use cupcake liners or parchment paper to provide a barrier.
When using condiments or any food item from a reusable jar, it is especially important to be aware of double dipping utensils or any other possible contact made directly between the jar and gluten-containing foods. If you are in a shared kitchen, it is advisable to purchase double of things like peanut butter, jam, mustard, and mayo, or to sort them into two separate containers, labeling one strictly gluten-free, before the first use to avoid cross-contamination. Another simple solution for some condiments is to purchase squeeze bottles. This will eliminate the possibility of cross-contamination as long as others in the household are diligent to not touch the squeeze bottle tip to gluten-containing foods.
Cross-contact can occur at the grocery store, too. For this reason, it is advisable to stay away from the store’s bulk section due to the presence of gluten-containing ingredients that could linger on scoops or surrounding bins, leading to cross-contamination. Even if the scoop is in the bin of a gluten-free food, it could contain gluten particles from a previous bin or from exposure to a gluten-containing food anywhere in the bulk bin area. Similarly, prepared foods from a store’s deli, hot bar, or salad bar are at risk for cross-contamination from the production kitchen to the food bar. Gluten-containing foods may be prepared on the same surfaces or with the same utensils as “gluten-free” items. Once prepared and out for sale, there can be cross-contamination via spills or accidental swapping of utensils from foods containing gluten into gluten-free items. As with approaching any potential source of cross-contamination, using your best judgement to assess the safety of food items is key.
It is especially important to be mindful of cross-contamination when dining out at restaurants that have not been certified through a program such as GIG’s GFFS program. It is advised to call ahead and speak directly with the staff to assess for risk of cross-contamination. The potential sources of cross-contamination listed above apply to restaurants as well as home-kitchens; an additional source unique to restaurants to consider is frying oil. If a gluten-containing food is fried in oil, the oil is then considered a source of cross-contamination as the exposure can leave gluten proteins on foods that would otherwise be considered gluten-free.
By knowing the facts and communicating with those around you, coming into contact with gluten can be averted. Though the prospect of preventing cross-contamination may feel daunting, it is an essential part of maintaining health and wellness for those with gluten-related disorders, and is absolutely possible to attain.
Article written for GIG by Tina Ralutz, Bastyr University Dietetic Intern. (2018)
This article has been assessed and approved by a Registered Dietitian Nutritionist.