Tanks should always be washed out thoroughly after
any racking so they are always clean and dry; a little water left in a tank
can allow bacteria to develop.
It is not necessary to sterilise
tanks before fermentation. The fermentation process itself
is about the strongest sterilising method there is.
SO2 solution has a slight sterilising effect but
doesn't kill everything, you can use it before racking a wine from one tank to another.
If you do happen to acquire a secondhand tank in a dirty condition then ideally steam it out (steam should flow
from the outlets for at least 30 minutes) using a powerful steam generator,
then pressure wash and scrub until it is clean. Steam is the most thorough
and safe method of sterilising, that's why it is used to sterilise the bottling line before filling.
The alternative is to use chemicals such as peracetic acid and/or proprietory cleaner/sterilisers.
New tanks have a protective plastic adhesive-film
covering the outer surface and the rim inside. This should be peeled off
carefully. The inside of the tank should then be scrubbed out with a scrubbing brush and cold water.
Winegrowers Supplies
- Cleaning stainless steel tanks