6.5 Gallon carboy - too big? (And other silly noob primary questions)

When I purchased my True Brew kit, I also purchased a 6.5 Gallon carboy, hoping to use that as a secondary. Now, after some reading it seems that 6.5 gallons is too big for a secondary, since it would allow 'too much oxygen/head space'? Although, the True Brew "ale pails" are 6.5 Gallons and obviously they work fine.

What gives?

I will probably be an extract only (kits probably) brewer for a year or so, so I don't want this thing sitting around waiting for me to do something with it. The way I planned it was to ferment in the 6.5 Gallon "ale pale" and then transfer big beers (well, big to me, like the NB Bourbon Porter, Guinness clones, etc) to the 6.5 Gallon carboy and get another brew going in the fermenter.

Also, I would love to stagger my "lighter" brews and do one in the Ale Pail and one in the 6.5 Carboy a week apart, so I can bottle more often....

Please advise - is 6.5 Gallons 'too big' for a primary or secondary fermenter, considering I will only be doing 5 Gallon brews?

THANKS!

6.5 gallon carboys are ideal for primary fermenters - there's more headspace for the krausen to build up before it starts leaving the fermenter through a blow off tube. You can lose a lot of volume through a blow off tube.

There's a lot of discussion about whether you really need to rack to a secondary fermenter. You don't HAVE to, even with big beers. You could just get a bottling bucket, and use both your fermenters as primaries. But let them ferment for at least 3 weeks is the general consensus.

Frodo, thanks for the quick response. To be clear, I don't plan on racking to a secondary often but I am planning a "Bourbon Barrel Porter" next and would need to rack atop some oak chips and whiskey... could I just pour this into the primary?

I am a noob, well read, but still a noob.

But from what I have read the "head space" from going from 5 to 6.5 is pretty minimmal. I have heard of people using a 15.5 gal fermenter with 5 gallons but that was as a primary NOT a secondary, I would be worried about this but what do I know?

I would think that you would have NO issues doing EXACTLY what you are doing as that is EXACTLY what I am doing. I cook my wort in 3 gallons, then add 2.5 for a total of 5.5 in the good old "Ale Pail" wait for the primary to finish 10-14 days-ish then siphon into a glass 6.5 gallon carboy where we have secondary for another 10-14 days-ish. Next bottle for 2 weeks and then comes the 1st taste.

days-ish = 2 hydrometer readings in 24 hours that are the same.
The reason I add water up to 5.5 gallons is I want 5 gallons of drinkable beer and you loose some from primary to secondary and then a bit more from secondary to bottling bucket. So, I will end up with a true drinkable 5 gallons.

Hope that helps.

As it was told to me: RDWHAHB and if this is your 1st batch RDW.

You want to minimize your beer's contact with O2, so if you can accomplish this you should be fine. In my experience, racking from the primary to the secondary kicks loose CO2 anyway, which forms a blanket over the liquid when it's transferred. The shape of the carboy is the key to it, not the size. You'll notice it becomes more narrow at the top and forms a neck. That means the closer it gets to that neck, the smaller the surface area is. A smaller surface area means less potential for oxidization, and less space that your CO2 blanket needs to cover.

So, if your beer produces a lot of airlock activity after transferring, you could be fine. If you're worried you can shoot some CO2 from a tank into the carboy (if you have one). If you really really need to get close to that neck, I've seen some crazy tricks. One is to keep a bunch (a whole bunch) of marbles around that you can sanitize and throw in there.

JustinBeer said:

Frodo, thanks for the quick response. To be clear, I don't plan on racking to a secondary often but I am planning a "Bourbon Barrel Porter" next and would need to rack atop some oak chips and whiskey... could I just pour this into the primary?

Click to expand...

Ok gotcha, so yeah I think your 6.5 gallon carboy would work fine as a secondary to rack onto the oak chips and whiskey.

I've read of brewers adding a little sugar to a secondary to force out all the oxygen. IMO for most beer it's unnecessary, particularly low gravity kits.