How Much Head Space

[Thrupney_Bit]

With the primary fermentation in my Devon cider over and the malolcatic bugs added to my demijons I'm now planning to move my cider to the coolness of my shed for maturing. I think I'm going to leave this one for around nine months to mature if I can resist the temptation!

My usual method is to prime and bottle into old Bulmer cider bottles and stash this away for carbonation and bottle conditioning. However, this year I'd like to do things differently and to leave the racked cider in the DJ with one of those DJ safety stoppers on (although I could probably get away with rubber bung I'm not taking chances - belt and braces!) on it to mature in bulk. The reason for this is that at the end of the maturation I'd like to taste test it to adjust any sweetness/acidity before then priming and bottling.

My question is this then, how much is safe to headroom before the bottom of the bung? I have tested the acidity and am happy that this is within the right range to prevent spoilage. However, there will be no further fermentation other than the gentle bubbling of malolacatic fermentation and it is because of this that I'm a wee bit concerned of spoilage. Are my worries unecessary? If anyone has some general advice that'd be grand!

Cheers

 

[oldbloke]

You want GraysAlchemy for this really, I don't know how much gas the malolactic process produces. Personally I'd be tempted to leave an airlock on just in case.

 

[graysalchemy]

You need to keep it under airlock as it will produce gas, also the MLF bacteria will produces quite an interesting layer of scum which you can harvest from the bottom along with any yeast and use on your next brew.

Well done with going for the MLF you will not be disappointed. :thumb:

 

[alanywiseman.]

You will need an air lock I left my cider in oil veg oil drums for about 7-8 months and it tastes great so dont worry about spoliage :thumb:

 

[Thrupney_Bit]

Nice one, thanks chaps. Top tip GA re harvesting the crud, I hadn't even thought of that!

Roughly how often does an airlock need topping up? I take it not often and depends on ambient temp, but roughly how often should I check it?