[Kate and her Ducks]

What is the reason for having a primary and secondary fermentation vessel? Is there really a reason to put it all in a bin and then transfer into a demijohn? Seems like a faff but will keep doing it if there is a good reason.

[BrianK]

Good question.  I always thought it was to loose the solids from whetever you are brewing. And the dodo that usually settles on the bottom in the first couple of days. But I would be interested to learn of a more scientific reason lol.   Oh  one of the other things is that primary fermentors can be any old toosh, like a saucepan or bucket wheras the secondary should have the filter on I think for sterile fermenting.

[poultrygeist]

All I know is that primary fermentation is aerobic (with lid/cloth to keep out flies) and may be done with the pulp still in so I guess it's easier to do in the bin.

Once you get to secondary it needs to be anearobic and sealed.

I would imagine you could use a demijohn for primary but if you leave the sediment in, it can taint the wine over the several weeks it takes to go through secondary.

Just guessing from what I've read but I think that's some of the reasoning.

Rob

[littlepete]

i use them big water bottles as my primary vessle and demijons as my secondary i think the reason is as you say is to seperate the liquid from the pulp i made the mistake once of leaving it in the primary for too long only for the wine to taste of mold that was a batch down the drain.

[SG6]

I think that the primary fermentation is to get the flavours, tannins, acids and whatever out of the fruit. After that the remains are no use and can go off so it is best to dispose of as much as possible. The primary also tends to be more active then the secondary.

As some of the fruit will have really broken down in to something fine it will get into the secondary but will (hopefully) percipitate out and form the residue at the bottom. Also the dead yeast cells will drop out as well.

If you make mead I believe there is no primary fermentation in a bucket or similar as there is no mass of solids to remove.

[Jay Dubya]

Hi, PG is spot on you need a bucket first because the aerobic needs air and the large surface area provides this also you can ferment on the pulp before the anaerobic, which dosn't need air and is safer in demijohns or closed fermentors, also you will find the ferment will start quicker with that large surface area.

[Kate and her Ducks]

Thanks all, always prefer to know why I am doing something.