Now I've read that a 5 gallon carboy or bucket is ok for primary fermentation since the co2 production is so high, it pushes out all of the excess oxygen. What about using the 5 gallon carboy for secondary fermentation? Will it produce enough c02 to purge the headspace or do i need to invest in a smaller carboy?
Personally I would recommend leaving it in the primary for approx 3 weeks and then go straight to keg or bottles. Eliminates the need for secondary mostly.
Personally I don't have any experience with a small batch and secondary fermentation, but what you could do to ensure there is enough co2 in the carboy is fill the carboy with co2 from your kegerator(providing you have one) prior to racking. This will ensure no o2 is in the carboy.
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