Cross-Contamination

People who need to eat gluten free need to check both the ingredients in food and any cross-contamination with gluten-containing ingredients that might happen when the food is manufactured, packaged and prepared for eating.

When you think about avoiding cross-contamination, you need to realize that crumbs matter. Look around your kitchen to see where there are crumbs – on the counter top, in the microwave, on the cutting board or in the corners of your metal baking dishes? Anywhere you see crumbs is a potential place for cross-contamination.

At home the following practices will go a long way toward avoiding cross contamination:

  • A celiac should have their own butter dish and a cutting board that is used for gluten free foods only.
  • A celiac should have their own toaster. A toaster oven, where the rack can be removed and washed if others have used it may be a good alternative. If you do not have access to a separate toaster, try a toaster bag, a silicon bag that holds the bread while it is toasted. The bread toasts right through the bag.
  • If it is not practical to have a section of the counter top set aside for preparing gluten free food only, always make sure that the counter space you are using to prepare gluten free food is freshly washed to ensure it is free from crumbs or flour dust.
  • Do gluten free baking first, and have it well wrapped and stored before doing anything with regular flours. Flour dust (in the air) from regular flours could settle on the gluten free products, thus contaminating them.
  • Note: Although this doesn’t fall into the cross contamination area, it is worth noting that a Celiac should take precautions against breathing in flour dust when using other than gluten free flours. Flour dust that settles on the nasal passages may eventually get swallowed and end up being digested.
  • When making sandwiches, do the gluten free ones first – otherwise be sure to wash your hands after touching regular bread and before touching gluten free supplies.
  • Use clean utensils and avoid “double dipping” – knives or spoons are OK the first time, but once they have touched food with gluten, they can contaminate the food in the container if used again. If it is too difficult to train other family members in this regard, it would be wise for the celiac to have their own jar of jam, peanut butter, mustard, etc.
  • Be especially alert and cautious when you have guests helping in the kitchen – they will not have your gluten awareness. Also, it is when you are otherwise distracted that you are more likely to make a gluten error.
  • Make sure any pots, utensils, etc. that are used for other foods are thoroughly scrubbed before using for gluten free foods. In the case of something like muffin tins, paper liners may be a worthwhile consideration.
  • It is best to have a separate set of utensils with porous surfaces, such as wooden spoons, for your gluten free baking. These utensils might retain some gluten particles after cleaning.
  • If using lentils, be sure to meticulously pick them over before putting in the pot to cook. Even if you buy them packaged, it is not uncommon to find kernels of wheat or oats (or pebbles) in with the lentils.

Away from home, be aware of sources of cross contamination:

  • Products in bulk bins can become contaminated by using the scoops in more than one bin. There is no assurance that the other customers will be as cautious as you. Also, flour dust in the air around these bins can cause a problem.
  • At the deli counter, where gluten free meats are being cut using the same utensils without cleaning in between or where cut meats often overlap on the counter.
  • Buffet lunches, where the chef tests the temperatures in all the dishes using one thermometer, or spoons are used for more than one dish.
  • French fries cooked in oil where battered foods have been fried.
  • Meat cooked on a grill which hasn’t been cleaned after cooking regular food with gluten.
  • Gluten-free pasta may be cooked in water used for regular pasta and rice may be cooked in broth containing gluten.
  • Milling of gluten free grains on equipment that has been used for regular grains.
  • In product production where a gluten free product is not produced on a dedicated line. Cereals and candy bars that have gluten free ingredients may be produced after a non GF item without having the equipment cleaned thoroughly in between.

Adapted from an article prepared by the CCA Calgary Chapter.