Description
Before winnowing, the beans are sterilized by steam. The hot cocoa beans are transferred from a continuous roaster or continuous dryer up-stream directly to the cocoa bean sterilizer.
In the sterilizer installed immediately after the dryer/roaster the hot beans are treated with approx. 2 bar of steam for approx. 40 seconds to obtain nearly bacteria free beans (500 –1.000 cfu (*) /gram).
At the same time the bean is being “popped” with this steam treatment. The volume of the bean is approx. 20% larger, caused by the intensive peeling of the shells. The treatment on hot beans after the dryer/roaster save a lot of energy against sterilizing of cold beans before a roaster.
Benefits
– High pressure and vessel temperatures possible
– Energy savings up to 25%
– Bacteria counts below 500 cfu(*) per gram after sterilization
– No risk of contamination of clean nibs
– Excellent release of the shell for optimum shell separation in downstream winnowing
– Short and low pressure steam treatment for moisture intake only on the shell
– Fast emptying and filling
(*) cfu = colony forming unit = rest count of bacteria after sterilising
