Hidden gluten checklist

Something is getting in and you can't find it. This is the list to walk around the house with. It's ordered by how often each one turns out to be the answer, so the top of the page is where to spend your first half hour. Tick things off as you go and the page will remember where you left off.

Start with what gets handled every day

Utensils and boards first, then the appliances. These are the things that touch food every day in a kitchen somebody actually lives in, which is why they turn up more than anything further down. What was measured coming off each one is in setting up the kitchen.

• Anything a knife goes back into

  Butter, cream cheese, jam, peanut butter, mayonnaise, hummus. A knife that has been on toast goes back into the tub, and that is the most common way gluten gets into a house that believes it is being careful.

• Knives and cutting boards

  Two of 28 lab samples came out over the limit. So usually fine, and the word usually is doing some work in that sentence.

• Wooden spoons, boards and rolling pins

  Hold a board up to the light and look at the knife marks. Every one of those is somewhere a scrub brush does not reach.

• The toaster

  Measured 5.1 to 8.3 ppm, under the threshold. We replaced ours anyway. You can empty the crumb tray, but it cannot be fully cleaned inside, and it touches bread every day.

• The colander

  Measured under 20 ppm. It is also a mesh full of crevices nobody can see into, and six dollars to replace, which is cheaper than thinking about it again.

• Frying pans with a scratched coating

  Run a finger across the cooking surface. If it catches on anything, that is a groove holding onto whatever went in the pan before.

• Sponges and dish towels

  Whatever you last wiped up is still in there. Theirs gets its own, in a different color so nobody has to think about it.

• Pet food and dog treats

  Wheat-based kibble gets handled by small hands that then go somewhere else.

Then what is in the food, and in the bathroom cabinet

Nothing here is visible by looking at the kitchen, which is what makes this the section that runs for months. Work down rather than picking the one that sounds most likely, because the one that sounds most likely has usually already been checked.

• Malt, malt extract, malt syrup, malt vinegar

  Barley, all four of them. Read the ingredient list itself: the allergen line underneath it covers wheat and says nothing at all about barley.

• Natural flavor

  Can carry barley malt inside it. Uncommon outside meat products, and invisible on the label when it does happen.

• Prescriptions, medicines, vitamins and gummies

  Wheat-derived fillers are common, and this is the one families miss for years. Write the full list out and have your pharmacist check each one. Do not stop anything yourself.

• Seasoning blends, stock cubes and bouillon

  A list hiding inside a list. The wheat goes into the sub-ingredients as a flow agent or a soy sauce powder.

• Soy sauce

  Most of it is brewed with wheat, and it turns up in marinades and seasoning powders as well as in the bottle.

• Oats that are not certified gluten free

  Grown, milled and hauled alongside wheat. Certified only, and some people react to the oat's own protein even then.

• Brewer's yeast and yeast extract

  Brewer's yeast is usually left over from making beer. Yeast extract depends what it was grown on and the label will not tell you.

• Wheat starch outside a gluten-free product

  On its own it is wheat. It only counts when the product around it carries the gluten-free label, which is what says it was processed down.

• Wheat flour in the air when somebody bakes

  It hangs for hours, reportedly 12 to 24 of them depending on the room, then settles onto every surface, including the clean plate waiting for lunch.

• Toothpaste and mouthwash

  These end up in a mouth, so they count. The one people miss is the brand that quietly reformulated after they checked it.

• Lip balm, stickers and craft glue

  Same rule. Anything a younger child licks, chews or sucks belongs on this line.

Away from your own kitchen

The two at the top of this section are the only ones anybody has measured failing, a shared fryer and a pot of water that has boiled wheat pasta. Both of them are worth knowing about and neither is likely in your own kitchen, because almost nobody deep fries at home or cooks two kinds of pasta in one pot of water. A restaurant does both, every night. That is why they sit here rather than at the top.

• A shared fryer

  Oil that has cooked breaded food stays contaminated the whole time it sits there. A quarter of samples came back over the threshold, some above 80 ppm. A dedicated fryer or nothing.

• Pasta water that has boiled wheat pasta

  33.9 to 115.7 ppm, five times the threshold at the low end. Cook theirs first in fresh water or in its own pot. Rinsing afterward brought samples back under.

• Grills, shared tongs and one cutting board elsewhere

  Grandparents, friends, teams, camps. It goes wrong the same few ways every time: one board, one set of tongs, a grill somebody wiped instead of covering.

• Play dough, sensory bins and the craft table

  Standard dough is wheat flour and hands go in mouths. Ask what the sensory bin, the paste and the paints are actually made of.

• Shared snacks, birthday treats, cooking lessons, reward jars

  The food nobody counts as a meal. School is the biggest blind spot there is, because you are not in the room when it happens.

• Bulk bins and shared scoops

  The nuts are fine. The scoop that moves from bin to bin is the problem, so buy the packaged version.

• The salad that arrived with croutons picked off

  Picking them off does not undo it. Send it back and ask for a new one, every time.

• Communion wafers

  A standard wafer is wheat. Low-gluten hosts exist and practice varies between parishes, so this is a conversation with your priest.

• Imitation crab, licorice, beer

  Three that still catch people who have learned everything else on this page.

Write down what you find and take it to your child's doctor or dietitian. The reasoning behind this list, including what normal recovery looks like and what else it could be when it isn't gluten, is in gluten free and still sick.

This is a checklist to work through and take to a clinician. It isn't medical advice and it isn't a diagnosis. Never stop or change a prescribed medicine to test a theory here, ask the prescriber or your pharmacist first. If your child is unwell, or anything is sudden or severe, the next step is a doctor.