The temperature within the beamhouse process liquor, especially liming, affects the cleanliness, smoothness of the grain and the degree of swelling and the uniformity of removal of fat. TFL recommends that great attention is paid to providing uniformity of process conditions, especially process temperatures throughout the year.
The temperature of liming needs to be high enough to ensure optimised chemical reaction but not so high as to cause damage to the fibre structure at the high alkalinity used for liming. This temperature is generally accepted as being 26-28°C for the hair removal stages with cooler water added for the liming stage to reduce the temperature to approx. 24 - 26°C and provide an excess of liquor. In any case the temperature must not exceed 30°C to avoid damage to the fibre structure.
Conversely very cold water will also have adverse affects on the liming process. Float temperatures below 20°C will cause problems from excessive swelling and low mobility of fat producing dirty drawn limed pelts.
In countries where temperatures may vary from hot in summer to cold in winter the input water temperatures should take into account the ambient temperature e.g. in winter an additional wash or even two washes extra may be required to bring the cold hides or skins plus the vessel up to correct temperature.