Why Is My Banana Bread Raw in the Middle and How to Fix It

The top is dark brown, the skewer looked fine, and then you slice it and find a damp, gummy stripe running through the centre. Banana bread raw in the middle is the most common quick-bread complaint I get, and it almost never means the recipe is broken.

It usually comes down to four things: too much banana, the wrong tin, an oven that runs hot or a test done in the wrong spot. Each one has a simple fix, and once you know which one you are dealing with, the next loaf comes out right.

What leaves banana bread raw in the middle

Banana bread is a heavy, wet batter. A typical loaf holds 300 to 400 grams of mashed banana, which is about 75 percent water. That water has to heat up and partly evaporate before the crumb in the centre can set, and the centre of a deep loaf tin is the last place heat reaches.

If the outside browns faster than the middle cooks, you get the classic result: a crust that says "done" and a core that is still batter. Here are the causes, roughly in order of how often I see them.

Too much banana

Recipes say "3 bananas", but bananas range from 90 grams to 160 grams peeled. Three large ones can add 150 grams more liquid than the recipe was tested with. Weigh the mash. For a standard recipe with 250 grams of flour, aim for 300 to 350 grams of peeled banana.

The wrong tin

A 2 lb loaf tin (about 23 by 13 cm) is what most recipes expect. Use a narrower or deeper tin and the batter sits higher, so the centre takes far longer to cook. A dark metal tin also browns the outside faster than a light one. Glass tins heat slowly and then hold heat, which overcooks the edges.

An oven running hot

Many home ovens run 10 to 20 degrees hotter than the dial. At 190C instead of 175C, the crust sets and darkens before the middle has a chance. A cheap oven thermometer, around 6 to 8 pounds, settles the question in one bake.

Testing in the wrong spot

A skewer pushed in near the edge, or at an angle, can come out clean while the true centre is still wet. Test in the exact middle, straight down to the base.

How to tell when banana bread is actually done

The skewer test is useful but easy to misread, because a skewer can pass through a gap or pick up a moist crumb that looks like batter. Use two checks together.

Internal temperature. A probe thermometer in the centre should read 95 to 99C. Below 93C, it needs more time, whatever the crust looks like.
The skewer. In the exact centre, it should come out with a few moist crumbs but no wet, shiny streaks.
The spring test. Press the top gently in the middle. It should spring back, not leave a dent.
The crack. The split along the top should look dry inside, not glossy.

Most loaves need 55 to 70 minutes at 175C (160C fan). If yours is at 50 minutes and the top is already deep brown, lay a sheet of foil loosely over it and keep baking. The foil stops the crust burning while the middle catches up.

The counter-take: lowering the oven temperature is not always the answer

The standard advice is to drop the oven to 160C and bake longer. Sometimes that helps, but it often makes things worse.

At too low a temperature, the baking soda reacts and releases its gas before the crumb is set enough to hold it. The loaf rises, then sinks in the middle, and a sunken centre is denser and wetter than before. You have traded a raw stripe for a gummy crater.

Before you touch the dial, fix the batter and the tin. Weigh the banana, use the right size tin, and check the oven with a thermometer. If those are right and the crust still browns too fast, use foil for the last 20 minutes rather than lowering the whole bake. Keep 170 to 175C as your baseline.

Saving a loaf that is already raw in the middle

If you cut it open and find it underbaked, you have options.

Back in the oven straight away. If it is still warm, put it back in the tin, cover the top with foil and bake at 170C for 10 to 15 minutes. Check the centre temperature again.
Toast the slices. If it has cooled, slice it 2 cm thick and toast the slices in a dry pan or under the grill. The wet centre firms up and caramelises. Many people prefer it this way.
Turn it into a pudding. Cube the loaf, pour over a custard of 2 eggs and 250 ml milk, and bake at 180C for 30 minutes as a bread pudding.

What does not work: microwaving the whole loaf. It steams the crumb and makes the dense stripe rubbery.

Small changes that prevent a gummy centre

These habits take a minute or two and solve most problems before they start.

Mix the flour in only until no dry streaks remain. Overmixing develops gluten and gives a tight, gummy crumb. If you are unsure how far to go, our guide on why resting dough matters explains how gluten builds up.
Use room-temperature eggs and melted butter that has cooled for five minutes. Cold eggs firm up the butter and stop the batter rising evenly.
Measure flour by weight rather than cups. A digital kitchen scale removes the biggest variable in any quick bread.
Line the tin with a parchment sling so you can lift the loaf out to test the base if needed.
Let it cool in the tin for 10 minutes, then on a rack for at least an hour. The centre keeps cooking from residual heat, and cutting early makes even a done loaf look gummy.

If you want to swap butter for oil or yogurt, adjust carefully, since extra liquid adds to the wet-centre problem. Our notes on substituting butter in baking give the ratios.

Frequently asked questions

Why is my banana bread wet in the middle but done on the outside?

The crust set and browned before heat reached the centre. The usual causes are too much banana, a deep or dark tin, or an oven running hotter than the dial. Weigh the banana and cover the loaf with foil once the top is brown.

What internal temperature should banana bread be?

Banana bread is done at 95 to 99C in the centre. Use a probe thermometer pushed straight down into the middle of the loaf, not near the edge, for an accurate reading.

Can you eat slightly undercooked banana bread?

A slightly moist crumb is fine, but a wet, batter-like centre contains raw egg and raw flour, which are best avoided. Return it to the oven under foil or toast the slices until the centre is firm.