Backslopping is the lazy brewers way to keeping sterile with minimum effort.
If you have any number of demijohns of cider that need racking off into clean demijohns you only need one additional sterilised empty demijohn in order to complete the task.
For example, last week I had three demijohns (lets call them a,b and c) full of half brewed cider and needed to rack them off.
I simply sterilised one demijohn and racked the contents of demijohn ‘a’ into it.
Then i just rinsed out the lees (the dregs at the bottom) from ‘a’ andimmediately racked off from ‘b’ directly into ‘a’ and reinserted the bung.
Then I rinsed ‘b’ with tap water and immediately racked off from ‘c’ directly into ‘b’ and reinserted the bung.
This technique is a variant on backslopping and saves a fortune in time, effort and sterilising solution. It works because the inside of the ‘dirty’ demijohns are effectively still sterlile at the moment you rack the juice out of them since the yeast and alcohol have stopped any other bacteria from getting in there.
If you keep using the same demijohn continuously it is possible to do this several times over without the need for sterilisation between them. Combining these techniques with boiling water and rigorous scrubbing should be sufficient to stop your cider getting infected.
Backslopping is a great cleanliness technique for people who brew continuously. By adding the ‘lees’ (the sludge that collects at the bottom of a vessel during fermentation from the previous brew to the new juice you can be assured that the lees are sterile, due to all the alcohol and are so free from infection. They kick start the new fermentation process, eliminating the chance of infection that comes from leaving the bottles and other vessels hanging around.