How to test bread doneness without a thermometer

Why your ears and eyes still beat a thermometer

There is nothing wrong with a digital thermometer. It is a useful tool, and if you bake a lot of enriched bread you will probably want one eventually. But the thermometer only tells you about the middle of the loaf at the moment you probe it, and it leaves two little holes behind every time. Baking has been done for thousands of years without one, by bakers who relied on their senses — and those senses are more accurate than most of us give them credit for.

Bread is ready when the crust has set to a deep, dry colour and the interior has turned from wet dough into an elastic crumb. You can detect both of those things without a probe. What you are looking for is a combination of cues: the sound a loaf makes when you tap it, the colour and feel of the crust, the smell coming off it, and the way it behaves as it cools. Learn to read these together and you will rarely need a number again.

The tap test, done properly

This is the classic test and it is still the most useful one, but it has to be done correctly. Tapping the top of a loaf through a tin tells you almost nothing, because the metal deadens the sound.

• Turn the loaf out of the tin first. Wear a tea towel or oven gloves — the tin will be very hot.
• Hold the loaf on its side or balance it on your hand and tap the base firmly with your knuckles, or with the handle of a wooden spoon if it is too hot to touch comfortably.
• Listen for a hollow, drum-like ring. That is the sound of a set, dry crust with a light structure behind it.
• A dull thud means more time. So does a feeling of heaviness and density in the hand.
• For free-form loaves baked on a stone, slide the peel or a sheet of parchment under the loaf and tap the base that way — never tap the top.
• Give it another five minutes if you are unsure, then tap again. Overbaking by five minutes is far kinder than underbaking by five.

One word of caution: a dense loaf will sound duller than a light one even when it is properly baked. Which brings us to the next check.

Reading the crust: colour tells the story

Crust colour is the most visible signal of doneness, and it is also the easiest to misread. Pale gold means the loaf is not finished. A plain white dough wants a deep, even chestnut-to-mahogany tone, with the base as dark as the top. If the base is still patchy and pale, the loaf has not had enough heat underneath — turn it out, put it back in the tin upside down, and give it another ten minutes on the shelf below the middle.

Wholemeal and rye loaves should go darker still, towards a rich brown or near-black. Watch the transition carefully, though: bran and whole grains contain sugars that catch and burn long before the crumb is set. If your crust is darkening fast but the tap still sounds dull, drop the oven temperature by 15–20°C, cover the top loosely with foil, and bake it longer and slower.

As it cools, a properly baked crust often crackles and ticks — bakers call it singing. It is a good sign that the crust is dry and rigid, though a quiet loaf is not necessarily an underbaked one.

Smell, shrinkage and the skewer

Open the oven door and breathe. A finished loaf smells nutty, toasty and faintly sweet. A loaf that still smells yeasty, raw or floury needs more time, no matter how it looks.

Shrinkage is another quiet clue. A tin loaf that has pulled away from the sides of the tin, leaving a narrow gap, is almost certainly done. If it is still clinging to the sides, give it longer.

For enriched doughs — brioche, milk bread, anything with a lot of butter and sugar — the tap test is less reliable, because a rich crumb stays soft and heavy. Here a thin skewer pushed into the centre is genuinely helpful. It should come out clean or with only a few dry crumbs. Any smear of wet dough means back in it goes, loosely covered with foil so the crust does not scorch.

How heritage grains change the cues

Spelt, emmer, einkorn and rye all behave differently from modern bread wheat, and they will throw you off if you judge them by the same rules.

• Einkorn browns very quickly because of its high carotenoid content. A deep colour arrives early, so trust the tap test and the skewer more than the crust here.
• Spelt and emmer have more fragile gluten and a looser structure. They tend to bake a little faster, and their crust sets sooner than you might expect.
• Rye has very little gluten and a dense, sticky crumb. Even a fully baked rye loaf sounds duller than a wheat loaf. Judge it on crust colour, on having baked it long at a moderate temperature, and on resting it for a full day before cutting.
• Freshly milled wholemeal flours absorb water differently and often need a slightly longer, cooler bake to set the centre without burning the outside.

As a rough guide, a 500g tin loaf wants 35–45 minutes at 200–220°C, a 900g loaf 45–55 minutes, and a sourdough boule 40–50 minutes, with the first 20 minutes under a lid or in a covered pot.

Cooling is the last stage of baking

The loaf is not finished when it leaves the oven. Carryover heat continues to set the crumb for several minutes, and steam is still working its way out of the centre. Leave a tin loaf in its tin for five to ten minutes, then turn it onto a wire rack so air can reach the base. Free-form loaves can go straight onto the rack.

Then wait. Slice a hot loaf and you release all that trapped steam at once, and the crumb turns gummy and pasty — the very thing you were testing to avoid. Give a wheat loaf two hours, and a rye loaf a full day if you can bear it. Cut it cool, and every cue you read earlier will be confirmed in the first slice.