Can everyone who avoids gluten eat oats?

Not quite everyone. Oats contain avenin, a protein similar to gluten. Coeliac UK says most people with coeliac disease can eat gluten free oats, but that a very small number are also sensitive to avenin. If you follow a gluten free diet on medical advice and are unsure about oats, check with your healthcare team before relying on any oat-based food, including the recipe and the bars on this page.

How do you make flapjacks without oats?

Swap the 300 g of oats for the same weight of buckwheat flakes, or a half and half mix of buckwheat and quinoa flakes. Despite the name, buckwheat is not wheat and is naturally gluten free, though the same rule applies: buy flakes labelled gluten free.

Flakes are finer and thirstier than oats, so two adjustments help. Bake for 3 to 5 minutes less, and press the mixture especially firmly. Expect a denser, more biscuit-like bar with a nuttier flavour.

Which flapjack ingredients can hide gluten?

Butter, sugar, honey and golden syrup are naturally gluten free. The risk sits in the oats and in whatever else goes in.

• Barley malt extract. It appears in some breakfast cereals, malted syrups and chocolate.
• Wheat flour. Some shop-bought flapjacks use it as a binder.
• Add-ins. Biscuit pieces, some chocolate chips and yoghurt coatings may contain gluten or carry a “may contain” warning.
• Toppings. Check sprinkles and caramel sauces.

Read every label, every time. Recipes change without the front of the pack changing.

How do you avoid cross-contamination when baking at home?

Treat a shared kitchen like a shared factory. The oats can be perfect and the flapjack still pick up gluten from the equipment.

1. Wash the tin, pan and spoon first, and line the tin with fresh baking paper.
2. Use a metal or silicone spoon. Wooden spoons are porous and hold on to flour.
3. Open a fresh pack of butter. The tub that sits next to the toaster usually has crumbs in it.
4. Wipe the worktop and scales before you start.
5. Store the finished bars in their own labelled tin, not in with other baking.

Which gluten free flapjacks can you buy?

I make one of the options below, so read this section as the maker’s view and compare for yourself.

Bakery flapjacks. Flapjackery says all of its flapjacks are made with gluten free ingredients and uncontaminated oats. Yorkshire Flapjack sells a Gluten Free Original at £2.50 with a three-month shelf life (both checked 12 October 2026). Most supermarkets also stock flapjacks in the free-from aisle. In every case, look for the words “gluten free” on the pack itself.

For long days and big appetites. Phoenix Bars are the high calorie bars I make for endurance events, expeditions and people who struggle to eat enough. Each is a 120 g oat flapjack made with gluten free oats, with 527 to 557 kcal, 60 to 66 g of carbohydrate and about 18 g of protein. They are also vegan and cost £5.25 a bar.

Phoenix Bars are labelled gluten free. My manufacturer tests the bars for gluten as they come off the line and again before dispatch, against the 20 parts per million threshold. The site that makes them also handles products containing gluten, which is exactly why that testing matters and why I say so here.

Eight of my 397 published reviews mention gluten. Conor B., training for a winter mountain ultra, wrote: “I find gluten hard to digest whilst running so I enjoyed that these flapjacks are gluten-free.” Alan G. wrote: “I struggle to find gluten-free nutrition so they were the perfect fuel for my recent 100km ultra marathon.” And Ned H., a mountain leader, wrote that “the fact that it’s vegan and gluten free also makes it an ideal emergency snack to bring with me when I’m guiding people who might have specific dietary requirements.”

The main downside is texture. Phoenix Bars are drier than a butter-and-syrup tray-bake, and most of the 11 reviews at three stars or below say so. If you want a soft, sticky flapjack, bake the recipe above. If you want a compact bar that keeps for up to two years and survives a rucksack, take a sip of water with each bite or turn the bar into porridge.

Allergen note: Phoenix Bars contain soy, the Cherry Bakewell flavour contains almonds, and some flavours contain sulphites. The label carries a “may contain” warning for milk, egg, nuts, peanuts and sesame.

For event fuelling, my guide to the best energy bars for ultra running compares more options. If eating enough is the harder problem, see my list of high calorie gluten free foods, or read how people use Phoenix Bars as high calorie bars for weight gain.

How long do gluten free flapjacks keep?

Homemade gluten free flapjacks keep for up to a week in an airtight tin at room temperature. They freeze for up to three months if you wrap the bars individually. Thaw at room temperature for an hour or two.

Frequently asked questions

Do gluten free oats bake differently from ordinary oats?

No. Gluten free oats are the same grain, grown and milled under controls that keep wheat, barley and rye out. They behave identically in a flapjack, so any standard recipe works.

Is golden syrup gluten free?

Yes. Golden syrup is made from sugar and is naturally gluten free. Check the label on flavoured or own-brand syrups.

Can you make gluten free flapjacks with less sugar?

You can cut the sugar and honey by about a fifth before the bars stop holding together. Honey is still sugar, so swapping one for the other changes the flavour but not the total by much. For a bar that is richer without being sweeter, add 75 g of peanut butter and 50 g of chopped nuts.

Why are my gluten free flapjacks crumbly?

The usual causes are the same as for any flapjack: the mixture was not pressed down firmly, the bars were cut while warm, or the sugar and syrup were reduced too far. The oats being gluten free is not the reason.

What is the highest calorie gluten free flapjack?

Most flapjacks sit between 430 and 480 kcal per 100 g, so the size of the bar matters more than the recipe. My high-calorie flapjack recipe reaches about 490 kcal a square and works with gluten free oats. For ready-made options, I compare the highest calorie bars in the UK in a separate guide.

Related guides

• Vegan flapjacks: easy 4-ingredient recipe
• Flapjack bars: what to buy and how to make them
• High calorie protein bars from Flaming Phoenix

This page is general information, not medical or dietary advice. Product details for other brands are taken from their own websites on the date shown, so check the pack before you buy.