Carboy Size With No Secondary

[chrisvaf]

Hey everyone. After 4 consecutive brews that blew off significantly, I'm re-thinking my fermentation vessel. A quick recap of my setup:

1. I ferment in a temperature controlled chest freezer. I insulate the probe to the wall of the carboy and set the temperature to 66 for the first few days, then gradually bump up to 71 or 72 after active fermentation has stopped. I have only used dry yeast, the last using one pack of S-04 for a 1.069 OG beer.

2. I use 6-gallon PET carboys. I don't do secondaries - I let it sit in the fermenter for 3-4 weeks before racking to keg.

3. I connect a stainless steel blow-off tube to the stopper, then down to a water jug filled with sanitized water, high enough so that the blow off tube is submersed.

With this setup, there has been so much blow-off that it has overflowed from the jug, causing a mess in the chest freezer. I now put everything in a plastic bin so that cleanup is easier but still, not fun. In my current brew (a Rogue Chocolate Stout Clone) I changed my jug to a taller one which seemed to hold the blow off quite well, however the pressure in the carboy caused the stopper to pop, causing an additional mess all over the carboy.

So, all that to say that I'm now thinking of getting a bigger carboy for fermenting. I'm looking at the 7.5G FerMonster - http://www.thevintageshop.ca/products/fermonster.html

The question I have which I've had a hard time finding an answer to searching the forums is whether or not the large headspace will be ok for the 3-4 weeks that the beer will sit here for. I don't want to switch back to a secondary and figure any secondary time needed will be spent at room temps in the keg.

Cheers!

 

[GHBWNY]

You didn't mention what size batch you are putting into a 6-gal vessel. To avoid a super-blow-off, a 5-gal batch should use a minimum of a 6.5 gal. fermenter. A 5.5 gal batch, obviously an even bigger vessel. By its shape, a carboy tends to funnel blow-off out the airlock/tube more than a plastic bucket or a BMB, which have a greater lateral headspace to accommodate the rising kraussen.

 

[chrisvaf]

You didn't mention what size batch you are putting into a 6-gal vessel. To avoid a super-blow-off, a 5-gal batch should use a minimum of a 6.5 gal. fermenter. A 5.5 gal batch, obviously an even bigger vessel. By its shape, a carboy tends to funnel blow-off out the airlock/tube more than a plastic bucket or a BMB, which have a greater lateral headspace to accommodate the rising kraussen.

My bad - sorry. I add 5.25 G of wort into the vessel. The 7.5G FerMonster will definitely help here but my original concern of leaving it in there for 3-4 weeks has me worried.

 

[GHBWNY]

Although a smaller vessel would be ideal, no big worries with the 7.5. The beer post-ferm will have a "blanket" of CO2 on the surface, plus your beer will have reached peak ABV by then. So if conditions remain sanitary and there is no vigorous introduction of O2, you should be OK.

 

[kh54s10]

I put about 5.25 gallons in my 6 gallon better bottles. Some blow off and others don't. I really don't worry about whether it does or doesn't.

Why do you need it in primary for 3-4 weeks? Try 2-3 weeks. But you shouldn't have any problems with the 3-4 weeks. I left a beer in a 6 gallon better bottle for 5 months and it was still pretty good.

 

[PKnotlost]

Definitely go bigger don’t worry about the dead space it will all be co2

 

[beermanpete]

A larger fermetner will help. What is the diameter of your blow-off tube? If the cork is coming out the blow-off tube may be too small and blocking with the krausen and yeast.

 

[stlbeer]

Use Fermcap-S to help control your krausen. It is a process aid that does not make it's way into the final product. https://www.midwestsupplies.com/fermcap-s-foam-inhibitor-1-oz
2 drops per gallon. It's cheaper than new carboys.