How To Go Gluten-Free: Avoiding Cross-Contamination At Home

photo credit: Flickr Laura Appleyard

Since this month is National Celiac Awareness Month, I thought I’d share some tips throughout the month to help you get started on a gluten-free diet. Previously, I’ve shared why I’m gluten-free (and the symptoms of a gluten intolerance or celiac disease) and some tips on how to go gluten-free for the beginner. But even if you’re no longer a newbie, hopefully this information can be a good refresher, and if you have additional tips, please share them in the comments. Many brains together is better than just my little ol’ noggin!

Let’s talk cross-contamination. What is cross-contamination? In this situation, we’re not talking about salmonella cross-contamination – you know, the kind that could happen if you put raw chicken on your cutting board that you subsequently use to cut raw vegetables. Today, let’s discuss gluten cross-contamination.

When otherwise gluten-free food comes in contact with food containing gluten, this is called cross-contamination.

How does this occur? Through a variety of ways. Since everyone has been talking about the not-so-gluten-free “gluten-free” pizza crust at Domino’s lately, let’s use this as an example, even though it takes place in a restaurant. This crust is gluten-free before it is removed from its package. However, once an employee removes it from the package, and sets it on the preparation station where gluten-containing crusts have been placed, that crust now has some gluten on it from crumbs. Furthermore, the toppings were touched by employee’s hands/gloves that were previously touching gluten, and all of the utensils used to move that pizza and cut it into slices were used on gluten-containing pizzas. Chances are, there are quite a few gluten-containing crumbs on that pizza when it’s served to a guest. This pizza has been cross-contaminated. (FYI, many people with celiac disease or other gluten sensitivity react to as little as 20 parts per million. This equates to the smallest of crumbs of bread. Even if a reaction doesn’t occur, damage could still be occurring.) This same cross-contamination situation can happen anytime gluten-containing food and gluten-free food is prepared in the same area – in a restaurant, in a food manufacturing facility, or in your own home.

What can we do about it? How can those of us that need to eat safe, gluten-free food (or provide safe food for our children) ensure that cross-contamination doesn’t occur in our home?

Of course, some of you may opt to remove gluten from your home entirely. This may be due to the fact that most or all of your family has issues with gluten, or there are small children that must eat gluten-free. It does make things easier. Then all that you have to do is read labels and be diligent about what foods you bring into your home to ensure they are gluten-free. Using a company such as Gluten-Free Watchdog can help too, as they run tests on even products labeled “gluten-free” to determine whether they have been contaminated by gluten.

But what about the great many of us that live in “mixed” households? How can we avoid cross-contamination? Here are some tips that work well for me.

Have a dedicated area for gluten-free items (or if majority of kitchen is gluten-free, gluten items) in your pantry, in your fridge, etc. Label them clearly – especially those gluten-free jars of peanut butter, mayonnaise, and the like. (Don’t want any gluten-y crumbs in your gluten-free condiments!) For certain items like that I use a big permanent marker and write my name on it. If you have young children, putting brightly colored tape around a jar might be a great way to let them know that product is safe for them. Store gluten-free products on a higher shelf than gluten-containing products, so if by chance, a bag spills, the gluten-y crumbs don’t fall into the gluten-free products. Educate everyone in your home so they know where the safe gluten-free foods are and that they need to keep them safe.

Thoroughly clean counters after cooking, so you won’t have to wonder if a stray crumb is gluten-free or not. Get down to eye level on the counters and inspect. You can also opt to designate one counter or one special area for all gluten-containing food preparation, to make it a bit easier. Other areas to think about cleaning: silverware drawer (notorious collecting crumbs) The drawer below your oven – mine gets crumbs from the oven in it pretty often. Pay attention to other surfaces that gluten-y hands touch – refrigerator handles, backs of chairs, the faucet handle, light switches. And how about that dish towel? Do your kids wash their hands at the kitchen sink? Mine do – and they are not gluten-free. They’re better about actually washing now that they’re older, (I used to have to watch them to ensure they’d do more than a quick rinse and wipe dry.) but still – if there is gluten on their hands after they wash, and then they use the dish towel to dry, that dish towel is contaminated. Also, my family often uses the dish towel to clean up anything from spilled water to milk or crumbs. Normally it goes into the dirty laundry afterwards, but if Mom or Dad aren’t around, the kids use the towel and put it back on the counter. If I wasn’t diligent about replacing that towel ALL THE TIME (we store a lot of clean towels around) I’d end up with gluten (or who knows what, for that matter!) on clean dishes or my hands. We do also use paper towels, (yes, I realize that’s not so green) but you and I both know that some kids (or even adults) will just grab the first thing they see!

Have separate toasters for gluten-free bread. Gluten-containing crumbs could stick onto the toaster and make their way onto the gluten-free bread. (Alternatively, you can “toast” gluten-free bread in a skillet – I don’t often eat bread, so when I do, I just heat a cast iron skillet with a bit of dairy-free butter or coconut oil and “toast” a slice that way. Delish.) Have separate cutting boards, especially if you ever cut gluten-containing bread on your cutting board. Replace or use separate cookware, mixers, blenders, wooden spoons, rolling pins,  flour sifters, pizza stones, colanders, etc. that previously were in contact with gluten. Some tools can be well-cleaned and reused – like stainless steel cookware, which is non-porous. Tools previously in contact with gluten should not be used if they are plastic, wooden, Teflon, cast iron, or any similar surface that can have small scratches/crevices that cannot be easily cleaned. Even baking pans that have metal seams or small edges that are hard to clean are suspect. Use your best judgment when making a decision about whether to replace or clean a certain tool. Gluten is sticky and likes to hide in these small crevices, so if you know there’s no way you’ll be able to effectively clean it, it’s best to replace.

– Check your spices. Single-ingredient spices (such as oregano, sage, cumin, etc.) should be gluten-free, but read labels on those mixed blends. Also, consider this: did you ever use a dirty measuring cup/spoon to measure out spices, after that measuring cup/spoon was used for flour? This could have contaminating the jar of spices. The same can be said of sugar and other naturally gluten-free baking ingredients – if you used the same measuring cup for the flour and the sugar in the past, it’s best to toss the sugar and buy fresh.

– If you have people in your home that prepare gluten-containing foods in your oven or on your grill (think frozen pizzas on the oven rack, or buns on the grill), you may wish to place gluten-free foods on a piece of foil rather than directly on the oven rack or grill grates, in order to prevent cross-contamination. Also, if you fry foods, be sure you use clean oil to fry gluten-free foods. Never use oil that previously fried gluten-containing items to fry gluten-free foods, as small gluten-y particles could be lingering in that oil and can then stick to your gluten-free food. Bake gluten items on foil or a dedicated baking sheet – not directly on the rack, to keep the oven safe. Teach gluten-eaters to assemble sandwiches, etc. on plates and not directly on the counter – and if possible, assign a designated space for them to prepare gluten-containing foods.

– If preparing gluten items, make sure to thoroughly wash hands your afterwards. If you were handling crumbs or flours, you may want to use gloves or clean with a nail brush as well, otherwise, your hands could contaminate the gluten-free items. Don’t touch any gluten-free foods with hands after handling gluten items. Same goes with utensils.

Use separate sponges for gluten and gluten-free dishes. Remember how I said that gluten is sticky (What happens when you mix flour and water? You get glue!)? It’ll stick to your sponge, especially if you’re cleaning out a bowl full of gluten-containing sticky pasta or something of that consistency. Then, if you were to use that same sponge on your gluten-free dish, you’ve wiped gluten all over that dish. I have a different-colored “gluten” sponge for these items, and the family knows to use that when they clean the few gluten-containing dishes that we sometimes use.

– If someone is baking with wheat flour, this can be quite tricky. Airborne flour can stay airborne for many hours, and then can settle on every surface around. It’s best to not use wheat flour in a home where people must eat gluten-free. However, if you do decide to use wheat flour, try mixing the flour outside. If the gluten-intolerant person is mixing the flour, having them wear a mask would be good. Once a “batter” is made, the flour won’t be airborne any longer, and the batter can be brought inside. (I did this with my step-daughter once upon a time, and shared my experience.) Again, use tools dedicated to gluten baking only.

A few other areas you might not think to look for gluten:

In your pet’s food. I personally haven’t read the labels on cat food – we don’t have cats – but dog food, especially the cheaper stuff, can contain wheat, barley, or oats. My dogs like to give kisses. If they were eating gluten in their food, then they’d be transferring that gluten to my hands (and the hands of the kids). This is something that could be particularly important if your kids must be gluten-free, as they’re more likely to let the dogs kiss them, and subsequently put their fingers in their mouth.

People kisses are sometimes a problem too. If we’re talking about mouth-to-mouth kisses, and your significant other has recently consumed gluten (even just a beer), then this can potentially make you sick. On that same note, don’t share forks or drink after someone that is eating gluten. There could still be crumbs on that fork, or their drink could be contaminated. And while 99% of us probably never do this, don’t share toothbrushes either.

Medications and supplements can also contain gluten as a binder. This is a bit more tricky – supplements have gotten better at labeling over the past few years, but most of the time, you’ll have to do research on your medications to ensure they’re gluten-free. Your pharmacist may be able to help you out, and there are some resources out there on the web. I’m hoping legislation passes for the requirement of gluten-free labeling in medications soon!

Yes, gluten can “lurk” in a lot of places in your home. And this does look like a lot of places to inspect. If you’re just starting out, don’t beat yourself up if you miss something. Heaven knows I have! Believe me, though, once you go through and make initial adjustments, keeping your home safe for those who must be gluten-free can become a simple, normal routine. Find what works best for you.

If you or someone in your home has been gluten-free for a while, but there are still gluten-eaters at home, how do you keep cross-contamination from happening? Share in the comments!


  1. says

    Hi There Alta,

    Thank you for putting together this fantastic post for us. There has been so much great information and posts this month…almost hard to keep up with it all.

    The kisses part made me laugh. I’m deathly allergic to peanuts and so if my husband or daughter has any they have to sterilize…or no kisses from mommy!! :-)

    Overall, great tips. This post really highlights the care and thought that goes into cooking/baking around those with sensitivities.

    Be Well,

  2. Sarah says

    The kitchen sink can be an absolutely DREADFUL source of gluten contamination, at least it was for me! One basin has a garbage disposal. I would use it to dispose of leftover cat food. My cat’s canned food is gluten-free, but the treats I used to buy for her were not. (I only buy gluten-free treats and food for her now.) I’m sure before I went gluten-free it was used to dispose of all kinds of gluten-containing foods. I would put the leftover food in the garbage disposal and rinse it with the sprayer, thinking I was getting the sink clean. Boy was I wrong. I’ve been working on removing gluten contamination from my home for months. One night, I looked down at the sink. It was stained, which I assumed was from use over time. I pulled out a Brillo pad and began scrubbing. The basin looked shiny and silver. It was very dirty! I scrubbed out both basins but then realized I needed to run all the dishes through the dishwasher, because I’m sure most of them have been through the sink at one time or another, and even if they’d only been in the dishwasher, I wasn’t taking a chance. I ran all my dishes back through the dishwasher, having already done it once for several of them, and wiped down the shelves they sit on again, after also having done that once before. I also realized all the food that may have been touched with any utensil from the sink or stored in any container washed there was contaminated, so I had to buy replacements. I had already bought replacements before because of the cleaning I had done in my utensil drawer. There were crumbs and even pieces of uncooked ramen noodles in it. I replaced anything I thought may have come into contact with those utensils. Basically, I ended up having to replace replacements. I’ve spent so much time and wasted so much money cleaning because of my kitchen and not realizing what a gluten trap it was. I think when you begin going over your kitchen, you need to tackle your kitchen sink and your utensil drawer at the very beginning! I would go over each COMPLETELY. I even cleaned the faucet pieces where the water runs through because they spent time in my utensil drawer when I was using a Brita filter on the faucet. That way, you can prevent continued contamination of dishes, food, etc. as you’re doing the rest of your cleaning and washing. I’m hoping I can prevent others from making the same costly mistakes that I’ve made!

    • Sarah says

      I also wipe down both kitchen basins with an antibacterial wipe and rinse the plug with soap and water every time I wash dishes.

  3. Betsi says

    Because of a recent gluten episode, I have been researching like crazy. In reading a blog/post somewhere the subject of the dish detergent for dishwasher came up. I never gave thought to this before but evidently not all detergents are gluten free. Talk about gluten contamination! Fortunately, the brand I am using is gluten free but made me realize just how susceptible gluten intolerant people really are & how we simply can not take ANY THING for granted!


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