Bread, hollow bottom sound reliability?

[Justin Pinkney]

The classic 'tell tale' sign that bread is ready is having a hollow sound when tapped on the bottom, almost every bread baking recipe happily recommends this as a fool proof way of telling bread is done. But, quite apart from figuring out just what a 'hollow sound' is, how reliable is this method?

It would seem to make sense that as excess moisture is driven out and the crumb is set that it should sound more hollow. But I have certainly had breads that sounded hollow, but were under done, or even had a core of unbaked dough in the centre.

Clearly temperature is the most reliable indicator, but is tapping a decent substitute (or are there any others?), and why always the bottom?

[Mjx]

. . . .

Clearly temperature is the most reliable indicator, but is tapping a decent substitute

Nope.

(or are there any others?),

Crust colour is a pretty decent guide (unless you brush some sort of muck over the top).

In fact, colour+temperature has always struck me as the best bet for determining bread doneness, because in my experience, bread actuallly reaches the correct internal temperature (which then goes little or no higher) before it's done. So, I bake the bread until it reaches a deep shade of brown. These days, when I've found the oven thermometer I have access to to be maddeniingly unreliable, I just follow the recommended baking time and temperature, then add however much more time is needed to bring the crust to a deep brown. It should be kept in mind that things like egg washes and so on brushed over the surface will (misleadingly) brown long before the bread surface itself is actually browned.

and why always the bottom?

This advice is so old I'm not even sure when or where it was first used, but there may have once been a good reason... or not (it may have just sounded more esoteric). I certainly don't know of any.

N.B. It's also possible that some people really do have a feel for how a finished bread should resonate (not just sound), sort of the way that Parmigiano Reggiano testers do, when they tap on the cheeses to determine their soundness. To my own undeveloped senses, the sound+vibration of a loaf of bread that's been baked always sounds relatively hollow (even when slicing it open reveals it is still doughy inside), and I'm guessing that that's the case for most people.

[Panaderia Canadiense]

There is a particular timbre to properly cooked bread when rapped, sort of like the sound of an ideally ripe melon or squash. FWIW, I'll tap both the top crust and the bottom when sounding the loaf, as I get a better idea of how the loaf is done that way (especially since I normally use an egg wash to stick seeds / grains to the top of my loaves).

I'm thinking it might be something that has to be learned when quite young - I was taught to sound bread by my great-aunt, using loaves from her wood stove.... I still listen for that distinctive tone when tapping my own bread, even though I'm baking in a gas oven. The sound is exactly the same.

[HowardLi]

Color is the most reliable for me.

[Broken English]

I was taught to push bread to as deep a golden brown as possible without starting to burn it. It's always worked for me, but it is true that bread has a particular sound when tapped, and with a little experience, it's also pretty reliable. For the most part, oven temperature for all the breads I've made has been the same, between 200 and 220 celcius thereabouts.

I would say that the reason for tapping the bottom has more to do with ensuring you have a flat surface which gives a more consistent sound from loaf to loaf.

[Blether]

IME colopur as a gauge for bread is a dangerous game. Fine if you're always using the same flour and you know what colour you like it at, but different flours brown to startlingly different degrees.

Edited June 7, 2012 by Blether (log)

[Panaderia Canadiense]

And woe unto you if you use a blend of specialty flours. Quinua, without the direct influence of the gas broiler, won't brown at all, even if the bread has become a hockey puck. Barley browns faster than wheat, and rye unevenly. And breads including golden pea or broadbean flours brown very quickly and stay that way.....

I'm going to keep tapping.

[Marie-Ora]

There is a particular timbre to properly cooked bread when rapped, sort of like the sound of an ideally ripe melon or squash. FWIW, I'll tap both the top crust and the bottom when sounding the loaf, as I get a better idea of how the loaf is done that way (especially since I normally use an egg wash to stick seeds / grains to the top of my loaves).

I'm thinking it might be something that has to be learned when quite young - I was taught to sound bread by my great-aunt, using loaves from her wood stove.... I still listen for that distinctive tone when tapping my own bread, even though I'm baking in a gas oven. The sound is exactly the same.

I agree - I learned from my Grandmother, who learned from her mother, and I know exactly what to listen for. But I think you 'get it' or you don't. My brother, who is a chef (not wild keen on baking) is convinced there is some voodoo in there with the bread tapping, because he never got it right like that

[David A. Goldfarb]

Tapping and listening works for me. I've never had underdone bread with this method. If it looks too dark, then it's overdone. Can't say I've encountered bread that was burned on the outside and raw inside, though I suppose it's possible at really high temperatures.

I suppose rapping the bottom might be because the bottom is more dense with some kinds of bread, and if you bake in any kind of loaf pan, you've got to take it out to rap it. Also there's no risk of messing up the top, if you tap the bottom.

[Justin Pinkney]

Thanks for all the replies, I guess it works for some. But even if you know the sound of done bread, surely this varies hugely between different types of loaf, e.g. ciabatta vs white sandwich loaf? Maybe someone should make a CD of example bread sounds.

Having to be the flat bottom makes sense though. But I think I'll stick to crust colour/temperature, I don't mind a discreet little hole from a temperature probe after all.

[Panaderia Canadiense]

If this makes any sense, it's more a timbre than a tone that you're looking for. In that respect, a ciabatta and a sandwich loaf are exactly the same.