Hi Mike

Thanks for your helpful comments. At the end of each day's processing I have
been washing the machine with hot water to remove the solids and any oil film.
At the end of last season I used Down to Earth dishwashing detergent to
thoroughly remove any remaining oil film. The detergent foamed badly which
made it difficult to rinse all traces from the machine and it was perfumed
which made me nervous about tainting the oil the following season.

As a result I was looking for an alternative and a friend who was a master
brewer had suggested an alkali or silicate for degreasing and quarternary
ammonium salts to sterilise.

Again many thanks.

Cheers
Steve Clark