With cakes and muffins, it is easy to stick a toothpick into the top to check for doneness, or to simply touch the top of the cake with a fingertip and see if it has set and springs back into place. With cookies, you can usually tell just by looking at them, and if you can’t, you can again touch an edge to see if it is slightly firm and set. Breads are much trickier. They have thick outer crusts that you can’t see through or feel through, and it is incredibly disappointing to let a loaf cool down for hours, finally slice into it and discover that it is underbaked.
Pro bakers (and many ammies) have baked enough bread to know when bread is done through feel and repetition. For the rest of us, the generic “tap the bottom of the loaf and if it sounds hollow, it’s done!” direction given in some cookbooks isn’t exactly enough. Nor is it enough to rely on the time range given without some kind of test, because ovens can vary widely in baking ability.
Fortunately, there is one reliable way and all you need is a meat thermometer. A fully baked loaf of bread will have an internal temperature of about 200F (or 94C), so just insert the thermometer into the center of the loaf and check the temp. If it’s not quite up to 200F, leave it in the oven for another few minutes. I always insert the thermometer through the bottom of the loaf, not the top. A chef once told me that this was simply the proper way to do it, so the steam inside of the bread doesn’t ruin the top crust. I don’t know how accurate this reason is, as I’ve never had any steam problems with my breads since I’ve been using a meat thermometer on them, but because I’m concerned with the aesthetic problems that putting a hole in the top of a loaf would cause, I’ll stick to going through the bottom of the loaf just in case.