Germination releases heat
which has to be controlled in order to keep the temperature around
60°F/16°C and avoid the barley killing itself from its own generated
heat. Traditionally the malting barley was drained and spread out in a
layer 30 cm or so thick over
a large floor then turned regularly by hand for about a week
with rakes or shovels. This was
repetitious and arduous work, leading sometimes to a repetitive-strain injury
called "monkey shoulder".
More recent maltings designs employed either mechanical rakes
or large revolving drums to achieve the same effect. A secondary effect of the
raking is to prevent the germinating roots from tangling with each other.