No, but you should get the wine out of the demijohn, clean it and transfer it back. You can put it in food grade buckets while cleaning, then get it back in the demijohn. You are going to have to rack it a couple of times more. It is much easier to just rack it into a different carboy or demijohn than rack it out and back again. Reason for doing this is you want to get it off the gross lees so they do not impart off flavors into the wine. Arne.
I also am using one demijon for a larger batch im doing. I do not want to have a second one just for racking so what i do is : I Use the juice buckets (3) to rack into then put the covers on while i clean the demijohn, then rack back into the demijon.
Yeah....that's what I was essentially going to do...I don't really have another option. The air contamination should be pretty low. I have a question....are you going to degas your wine? I have only come across one person who degasses
Yes i usually degas after fermentation is complete and before i start the bulk aging. However, i bulk age for at least a year and from what i have read it will degas on own over that time period. I still like to degas. I use a wine whip on drill. As i write this im sampling some California Merlot that has been bulk aging for 13 months. Taste great and ready to be bottled. I also tried a cold stabilization a few week ago on this batch. VERY pleased with the way it turned out! Taste is mush better that before the cold stabilization!