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 serious health issues like abdominal pain, bloating, diarrhea, constipation, headaches, fatigue and more. That’s why it’s important for people with gluten sensitivities or intolerance to understand which foods contain gluten and which foods are naturally gluten-free.
Potatoes are a nutritious gluten-free food that can be prepared in many ways, including au gratin. But the question is – do au gratin potatoes contain gluten? Let’s take a closer look.
What are Au Gratin Potatoes?
Au gratin potatoes are a classic French dish of sliced potatoes baked in a cream or cheese sauce. To make au gratin potatoes, thinly sliced potatoes are layered in a baking dish. A sauce made of butter, cream or milk and cheese is poured over the potato slices. The dish is then baked until the potatoes are fork-tender and the sauce is bubbly and lightly browned on top.
Traditional au gratin potatoes are creamy, cheesy and rich. The sliced potatoes provide starch and body, while the cheese sauce adds luxurious texture and savory flavor. Popular cheeses used in au gratin potatoes include cheddar, gruyere, parmesan and fontina. Herbs like garlic, onion and thyme are often added for extra flavor.
Do Potatoes Contain Gluten?
Potatoes are an inherently gluten-free food. The potato plant is not biologically related to gluten-containing cereal grains. Potatoes are tubers that grow underground on the roots of the potato plant. The potato itself is made up of starch, water, fiber and small amounts of protein and nutrients. But it contains no gluten whatsoever.
All varieties of potatoes are naturally gluten-free, including:
- Russet potatoes
- Red potatoes
- Yellow potatoes
- Purple potatoes
- Fingerling potatoes
- Baby potatoes
Potatoes are not a grain, so they share no genetic relationship with wheat, barley or rye. You can enjoy all kinds of potatoes, in all forms including baked, mashed, fried, au gratin and more, without consuming any gluten.
What Ingredients are Added to Au Gratin Potatoes?
While potatoes themselves are gluten-free, many recipes call for additional ingredients to make the creamy, cheesy au gratin sauce. Some of these added ingredients may contain gluten or be cross-contaminated with gluten.
Common ingredients added to au gratin potatoes include:
- Butter or margarine
- Flour
- Milk or cream
- Cheese like cheddar, gruyere or parmesan
- Herbs and seasonings
- Breadcrumbs or crackers on top
Let’s take a look at each of these ingredients and whether or not they contain gluten:
Butter or Margarine
Pure butter or margarine contains no gluten and is safe for gluten-free diets as long as it hasn’t been cross-contaminated. When buying butter or margarine, choose major name-brand products labeled “gluten-free.”
Flour
Most traditional flour is made from wheat and contains gluten. However, there are many gluten-free flour options that can be substituted, such as:
- Rice flour
- Tapioca flour
- Potato starch
- Cornstarch
- Arrowroot starch
- Almond flour
- Coconut flour
Be sure to use certified gluten-free flour to avoid cross-contamination.
Milk or Cream
Plain milk and cream do not contain gluten and are safe for gluten-free diets. Opt for pasteurized milk from cows or plant-based milks like almond, coconut or rice milk labeled “gluten-free.” Stay away from malted milk, which does contain gluten.
Cheese
Most cheeses are naturally gluten-free. However, some processed cheeses may have added wheat starch or preservatives that contain gluten. Stick to basic cheeses like cheddar, gruyere, parmesan and fontina from reputable brands labeled “gluten-free.” Avoid cheese sauces, spreads or sprays, as these often have gluten-containing additives.
Herbs and Seasonings
Fresh or dried herbs like garlic, onion, thyme, rosemary, parsley and oregano are gluten-free. Spice blends, salt and pepper are also fine on a gluten-free diet, as long as they are unseasoned. Make sure no wheat/gluten ingredients have been added.
Breadcrumbs or Crackers
Traditional breadcrumbs are made from wheat bread and contain gluten. However, you can make your own gluten-free breadcrumbs at home from gluten-free bread, rice crackers or potatoes. There are also gluten-free panko breadcrumbs available for purchase. Only use gluten-free breadcrumbs or substitute with crushed gluten-free crackers or potatoes.
Are Au Gratin Potatoes Typically Gluten-Free?
Classic au gratin potato recipes generally contain minimal ingredients beyond potatoes, butter, milk and cheese. None of these ingredients naturally contain gluten.
However, many modern au gratin recipes add wheat flour to thicken the cheese sauce. Some recipes also top the casserole with regular breadcrumbs or crackers for texture. These ingredients do contain gluten.
So in their most basic form, with no added thickeners or toppings, traditional au gratin potatoes would be gluten-free. But many modernized recipes and restaurant preparations may not be.
To make your au gratin potatoes gluten-free:
- Use butter, milk, cream and real cheeses verified to be gluten-free
- Skip the wheat flour as a thickener
- Substitute gluten-free flour like rice flour if needed
- Use gluten-free breadcrumbs or crushed potatoes instead of regular breadcrumbs/crackers
With these simple swaps, you can enjoy creamy, decadent au gratin potatoes on a gluten-free diet.
Are Restaurants/Frozen Meals Au Gratin Potatoes Gluten-Free?
If dining out or purchasing prepared frozen au gratin potatoes, additional caution needs to be taken. Many restaurant dishes and packaged foods contain hidden sources of gluten used as fillers, stabilizers and preservatives.
When ordering au gratin potatoes in a restaurant, ask your server about how they are prepared and what ingredients are included. Request any sauces or toppings be served on the side.
For frozen meals, carefully read nutrition labels and ingredients lists, looking for any sign of wheat, barley, rye or ambiguous ingredients like “flavors,” “starch” or “breading.” Call the manufacturer if ever in doubt.
Your safest bet is to make your own au gratin potatoes at home following a gluten-free recipe that suits your dietary needs.
How to Make Gluten-Free Au Gratin Potatoes
Making au gratin potatoes at home allows you to control exactly which ingredients are included. Here is a simple gluten-free recipe to try:
Gluten-Free Au Gratin Potatoes
Ingredients:
- 3 lbs russet potatoes, peeled and thinly sliced
- 1⁄4 cup gluten-free all-purpose flour
- 2 cups milk or unsweetened non-dairy milk
- 1 cup gluten-free chicken or vegetable broth
- 1⁄2 tsp dried thyme
- 1 tsp salt
- 1⁄4 tsp pepper
- 1 cup shredded cheddar cheese
- 1⁄2 cup shredded Parmesan cheese
- 2 tbsp butter or margarine, cubed
Instructions:
- Preheat oven to 350°F. Lightly grease a 9×13 baking dish with nonstick cooking spray.
- In a saucepan, whisk together flour and milk over medium heat until thickened to a sauce consistency. Stir in broth and season with thyme, salt and pepper. Remove from heat.
- Layer 1/3 of the potato slices evenly over the bottom of the prepared baking dish. Top with 1/3 of the cheese sauce.
- Repeat layers twice more, ending with sauce.
- Sprinkle cheddar and Parmesan cheeses over the top and dot with butter or margarine.
- Cover with foil and bake 45 minutes. Uncover and bake 15 more minutes until potatoes are fork tender and top is golden brown.
- Let rest 10 minutes before serving.
This simple recipe uses gluten-free ingredients like potatoes, gluten-free flour, broth, butter, milk, and cheese. Feel free to spice it up with your favorite herbs and seasonings too.
Conclusion
Plain potatoes are a naturally gluten-free food, so au gratin potatoes made traditionally with just potatoes, butter, milk and cheese would not contain any gluten. However, modern recipes and restaurant versions may call for wheat flour or breadcrumbs, making them unsuitable for gluten-free diets.
To enjoy safe gluten-free au gratin potatoes:
- Make them at home from scratch using gluten-free ingredients
- Avoid wheat flour – use gluten-free alternatives to thicken
- Skip the breadcrumbs topping
- Verify restaurant ingredients before ordering
- Read labels carefully on frozen meals
With a few simple swaps and precautions, you can still enjoy the classic flavor of au gratin potatoes on a gluten-free diet. This cheesy casserole made with sliced potatoes and creamy sauce makes a satisfying gluten-free side dish.