Why Gluten-Free Baking Turns Out Dry

The four causes

Almost every dry gluten-free bake comes down to one of these, and often more than one at once.

Cause	What is happening
Not enough liquid	Gluten-free flours and starches absorb considerably more liquid than wheat flour. A recipe converted directly from a wheat original will be short.
Batter baked too soon	Those starches also absorb slowly. Batter that looks right immediately after mixing is often still hydrating, and the oven locks that dryness in.
No gluten network	Gluten holds moisture in the crumb as well as holding it together. Without it, water escapes more freely during and after baking.
Starch retrogradation	The starches in gluten-free blends firm up and release water faster as they cool and sit. This is why a gluten-free muffin can be good on day one and dry on day two.

What to change

Rest the batter before baking

Five to ten minutes for muffins and cookies. This is the highest-value change on the list and it costs nothing. It lets the starches take up the liquid that is already in the bowl, so it hydrates the crumb rather than being driven off in the oven.

Use oil rather than butter where you can

Butter is roughly 80 per cent fat and 15 per cent water, and it is solid at room temperature — so a butter-based bake firms up noticeably as it cools. Oil is pure fat and stays liquid, which keeps the crumb soft for longer. Most of the gluten-free muffin recipes on this site use oil for this reason.

Add something that holds water

Mashed banana, apple sauce, yogurt, sour cream, pumpkin purée and honey all hold moisture in the finished bake in a way plain liquid does not. This is why gluten-free banana muffins are one of the easiest gluten-free recipes to get right — the fruit is doing half the work.

Stop baking earlier than feels right

Overbaking is the single most common cause. Gluten-free bakes often look pale and underdone when they are actually finished, which tempts people into another five minutes. Check at the early end of the stated range, and remember that everything continues cooking in the hot tin after it comes out.

Store it properly, immediately

Because of retrogradation, gluten-free bakes stale faster than wheat ones. Cool them completely, then seal them in an airtight container the same day. Refrigerating actually accelerates the process — the freezer is far better than the fridge for anything you are not eating within two or three days.

If it is gritty rather than dry

Grittiness is a different problem with the same fix. It means the starch particles never fully absorbed their liquid, so you are feeling dry flour in the finished crumb. Rest the batter longer — ten minutes rather than five — and check whether your blend is rice-flour heavy, since those are the grittiest.

If it crumbles apart

That is a binder problem, not a moisture problem. Check whether your flour blend contains xanthan gum; if it does not, add about 2 g per 250 g of flour. Also let things cool in the tin for five minutes before moving them, since gluten-free structure sets late.