Gluten is a protein found in grains like wheat, barley, and rye. For people with celiac disease or non-celiac gluten sensitivity, consuming gluten can cause adverse health effects. Many processed and packaged foods contain gluten as an ingredient or due to cross-contamination. People following a gluten-free diet must pay close attention to ingredient labels to identify and avoid sources of gluten.
What are au gratin potatoes?
Au gratin potatoes are a casserole dish of sliced potatoes baked with cheese and cream or milk. Traditional recipes call for russet or Yukon gold potatoes sliced thin, though any type of potato can be used. The potatoes are layered in a baking dish and topped with a cheese sauce made of butter, flour, milk or cream, and cheese like cheddar, Gruyère, or Parmesan. The casserole is then baked until the potatoes are fork-tender and the top is browned and bubbling. Packaged boxed au gratin potatoes provide the dry sauce mix and freeze-dried potatoes to which you just add your own milk, butter, and cheese before baking.
Are the potatoes themselves gluten-free?
Potatoes are a naturally gluten-free food. Potatoes are tubers, an edible root vegetable that grows underground. The most common varieties of potatoes like russet, red, yellow, purple, Yukon gold, and fingerling potatoes contain no gluten. Potatoes are not grains, so potato tubers themselves do not contain the gluten proteins.
Fresh, whole, unprocessed potatoes and homemade mashed potatoes are gluten-free and safe for a gluten-free diet as long as no unsafe ingredients are added. However, many processed potato products do contain gluten or risk of cross-contamination. This includes things like:
- Packaged shredded hash browns
- Frozen French fries
- Dehydrated potato flakes
- Pre-made potato gnocchi
- Potato chips or crisps
- Instant mashed potatoes
When buying any processed potato products, it is important to read the label carefully to look for gluten-containing ingredients. Assume nothing, and check every time.
What ingredients are commonly added to au gratin potatoes?
In addition to potatoes, traditional au gratin potato recipes contain:
- Milk or cream – The liquid added to the sauce helps create the classic creamy texture.
- Butter – Butter is used to make the sauce and add flavor.
- Flour – Flour thickens the cheese sauce so it coats the potatoes.
- Cheese – Cheeses like cheddar, Parmesan, Gruyère or Swiss add signature flavor.
- Onion or garlic (optional) – Onion or garlic powder can add flavor to the sauce.
- Herbs (optional) – Herbs like thyme or parsley add fresh flavor.
- Breadcrumbs (optional) – Some recipes top the casserole with breadcrumbs before baking.
When buying a pre-made boxed version, the included sauce packet contains thickeners like cornstarch or potato starch to create the right texture. Freeze-dried potatoes may also be included, to which you just add milk and butter before baking. The cheese sauce mix may contain milk powder, salt, vegetable oil, and seasonings.
Can these ingredients contain gluten?
Some of the additional ingredients commonly added to homemade or packaged au gratin potatoes can be sources of gluten:
Flour
wheat flour contains gluten. To make an au gratin sauce gluten-free:
- Use cornstarch, potato starch, rice flour, or tapioca flour to thicken instead of regular wheat flour.
- Verify flour is made from certified gluten-free grains like rice, quinoa, teff, corn, or oats.
Milk products
Plain milk, cream, butter, and natural cheeses are gluten-free. However, milk can be cross-contaminated if processed on shared equipment with gluten. Lactose-free milk and grain-based dairy alternatives like almond or rice milk can contain gluten. When buying milk products:
- Opt for verified gluten-free milk, cream, or cheese.
- Avoid dairy substitutes unless labeled gluten-free.
- Use caution with lactose-free milk; choose verified brands.
Breadcrumbs
Breadcrumbs are made from bread which contains gluten. To keep au gratin potatoes gluten-free:
- Omit breadcrumb topping.
- Use certified gluten-free breadcrumbs.
- Substitute with crushed gluten-free crackers or nuts.
Seasonings
Salt, pepper, herbs like thyme and parsley, and spices are naturally gluten-free. However, some seasoning mixes can contain gluten:
- Use single-ingredient seasonings tested for gluten.
- Avoid seasoning mixes unless labeled gluten-free.
- Check labels for anti-caking agents and starches which can be hidden sources of gluten.
Are boxed au gratin potatoes gluten-free?
Whether buying a pre-made boxed brand or making them from scratch, it is important to verify all ingredients are gluten-free. Here are some tips for choosing safe gluten-free boxed au gratin potatoes:
- Look for brands that are certified gluten-free. These have been tested to contain less than 20ppm of gluten.
- Carefully read the ingredient list. Watch for wheat flour, breadcrumbs, thickeners, and dairy ingredients.
- Call or email the manufacturer if you have any questions or concerns about ingredients or processing.
- If not certified gluten-free, look for brands that state “gluten-free” on the box. However, this label is not regulated.
- Be cautious of brands that only say “wheat-free”. These products could still contain barley, rye, or oat sources of gluten.
Here are some top brands of boxed au gratin potatoes that are labeled gluten-free:
| Brand | Certified Gluten-Free |
|---|---|
| Idahoan | Yes |
| Betty Crocker | Yes |
| Knorr | No* |
*Knorr’s box states gluten-free but is not certified
How are boxed au gratin potatoes made?
Understanding the way commercial boxed au gratin potatoes are manufactured can help identify potential sources of gluten cross-contamination. Here are some things to know about production:
- Most brands make both gluten-free and traditional wheat-based versions. Gluten-free lines are usually separate.
- Equipment is shared in some facilities; inquire about thorough cleaning protocols.
- Dairy, starches, and flours are common ingredients from shared suppliers.
- Packaging equipment may also handle multiple products.
Reputable gluten-free brands should implement careful quality controls like:
- Dedicated gluten-free manufacturing lines.
- Thorough equipment cleaning procedures.
- Testing of ingredients and final products.
- Audits of suppliers and facilities.
If concerned, look for brands that are certified gluten-free or produce their products in dedicated gluten-free facilities.
What about gluten cross-contamination risks?
Gluten cross-contamination is the introduction of gluten into an otherwise gluten-free food from shared manufacturing equipment, facilities, or ingredients. This can occur:
- On shared equipment that processes wheat-based foods
- From airborne wheat flour in facilities that also mill flour
- Ingredients sourced from suppliers that handle gluten-containing grains
- During packaging on shared machinery
To help reduce contamination risks, look for brands that:
- Are certified gluten-free with robust testing (20ppm standard)
- Use dedicated equipment just for gluten-free production
- Employ thorough sanitation procedures
- Use trusted gluten-free ingredient suppliers
- Have strict quality control measures in place
Though labeled gluten-free, there is no guarantee any processed food is 100% gluten-free due to potential cross-contact. Use your best judgment when deciding which brands to trust.
Should you make homemade au gratin potatoes instead?
Making au gratin potatoes from scratch at home lets you control all the ingredients. However, it can be more time-consuming than using a boxed mix. Here is some guidance on choosing homemade vs. pre-made:
- Homemade lets you use all gluten-free ingredients you trust.
- Pre-made mixes offer convenience but could have hidden sources of gluten.
- Weigh risks of cross-contact; homemade has less risk in a shared kitchen.
- Pre-made certified brands likely test rigorously for gluten.
- Make larger batches of homemade and freeze portions for later.
- Compare costs; homemade may be cheaper depending on ingredients.
The best option depends on your comfort level with packaged foods, how sensitive you are to traces of gluten, concerns about cross-contact, time constraints, and personal preference. Both homemade and reputable brands can be safe options.
What precautions should you take?
If you need to avoid all gluten, here are some precautions to take with au gratin potatoes:
- Carefully read all ingredient labels before purchasing or using.
- Verify “gluten-free” claims by calling manufacturers if concerned.
- Research brands and manufacturing practices for major gluten-free brands.
- Purchase certified gluten-free products tested to 20ppm or below.
- Look for brands produced on dedicated equipment or in gluten-free facilities.
- Wash hands thoroughly before prep and prevent cross-contact from kitchen tools.
- If very sensitive, consider making your own from scratch.
Conclusion
Boxed au gratin potato products labeled gluten-free are widely available from brands like Idahoan, Betty Crocker, and Knorr. When selecting a pre-made product, choose reputable companies you trust that implement rigorous quality controls and gluten testing. If concerned about cross-contamination, preparing your own homemade au gratin potatoes may be the safest option. As with any processed food, care should be taken to read labels and verify gluten-free claims when following a gluten-free diet. Being an informed consumer and asking questions can help you make the right choice.
