New Demijohns!

[Battleaxe]

Earlier I was discussing smaller brew batches, I'm happy to brew in a 5 gallon bucket with 2 gallons I've been told that the headspace shouldn't be an issue but I had already asked my dad about his old demijohns he had offered me recently so now I have three clear and two brown glass 1 gallon demijohns!

I measured them with 500ml jug and managed just over 8 before it overflowed :-( this means it's probably around 3.8lt to the neck...

My question is if I wanted to use two and split my fermentation across both what would an acceptable batch be to leave enough room for krausen etc?

I'm thinking 3lts in each? That would leave me with a possible 10 -12 bottles per batch which I'm happy with!

 

[MyQul]

If you wanted you could fill them right to the top and then rig a blow off tube. Get yourself down wilko and get a pack (as they come in two's) of those quiet air locks (not the bubbler type) and a syphon (you just need the tubing).

The quiet airlocks are two peice. Take the 'lid' off you just need the bit that jams into the bung. Get the syphon tubing and jam it onto the bit that's in the middle of the airlock where the C02 would come through. Then put the airlock into the bung and the bung into the DJ.
The other end of the tubing your going to put into a 'vessel' (jug, jar wherever you've got) fillled with Star san if you've got it. If not some boiled and cooled water will have to do (you cold use spirit's like vodka, similarly to what some people put in there airlocks). Job done Any yeast will just go down the tube and into the 'vessel'

 

[Battleaxe]

Hadn't thought of a blow off as it happens I have already got one from a previous batch!

I'm going to brew a 6lt batch per Clibits guide so I will make use of two demijohns anyway but in future I will be using this!