Bread dough at the right temperatureFor bread dough to rise well, it should be left in a warm place, protected from draughts. Bakers use a special room, for this called a "chambre de pousse" (growing room). Difficult to do this at home...
Instead I use my kitchen oven (off) where I put a small light bulb of 15-20 watts. This light bulb gives enough heat to reach 81°F (27°C) inside the oven.
Connect together lamp holder, flex, plug. Screw in light bulb.You can improve the sytem, by sticking (with epoxy glue) a magnet on the lamp holder, so it can be fixed anywhere inside the oven.
If you intend to buy:You can also use a more powerful light bulb (e.g. 25 watts) which will give you a higher temperature.