This is likely a silly question to a lot of you but I'm trying to weigh the pros and cons, no matter how minor, of a conical before I make the jump. I'm maybe too paranoid about oxidation, but one of the main selling points of conical manufacturers is less oxidation. I could actually argue the opposite: With the design of most conicals you're going to introduce oxygen, from the bottom, after you attach a second bulb and open the valve back up. RIGHT? What's everyone's thoughts on how much oxidation that can cause? Is there processes/valve designs that avoid this?

Currently I ferment in carboys and pressurize them to push back out the racking tube...mostly so that I can leave them in the bottom of my freezer w/o disturbing the trub. But also, depending on beer style and how long I'm going to age, I pre-prime the lines and keg and can probably guarantee very little contact with air...ever.

Now, I'm also leaving it in one vessel for primary, secondary, and sometimes even up to a week of lagering. So, the optimization I see by moving to conical is just getting it off that trub sooner w/o rerack. I hate reracking.

So what do you guys think? What's more important: avoiding that little bit of oxygen, or getting it off the trub ASAP? Can I get both?

FYI, conical(s) I'm looking at is the FastFerment. With a pretty tall collar, I'm thinking I can mount these inside a temp controlled freezer, and follow my same process, but get rid of yeast & trub sooner & more effectively.

2 Answers 2


First of all, once you remove the trub bulb, there is no need to add another one. If you don't add another trub bulb and open the valve, how are you getting your "glub"? The idea is, attach the bulb before you rack in your wort and pitch yeast, transfer the wort and open the valve (that way your hand is on the valve and you can verify that nothing is leaking), pitch yeast, walk away and don't mess with it until the gravity has stabilized. Once primary is complete, close the valve and remove the trub bulb. Add your secondary stuff and leave it alone. If you added fruit to secondary, you could reattach the bulb and open the valve a little until the bulb is full (I would leave the connection a little loose to allow air to escape), then tighten everything and open the valve to capture your fruit.

EDIT: I did some thinking about this over the weekend (you know how it is when something just doesn't sound right) and the conclusion that I came to is that yank the valve open won't hurt a thing. Here's why: when you allow the air from the collection bulb (it's about a pint) to come out in one big "glug", the only air that touches your beer is the beer on the outside edges of the spherical bubble(s). That's not a lot of air and only 21% of it is Oxygen. It's going to rise to the top of the beer pretty quickly and it's going to go to the top of the layer of CO2 that is on top of your fermented beer even faster.

TL;DR: Yank the valve open quickly... it won't hurt a thing. If it makes you uncomfortable to do that, drink a homebrew first.

  • Thanks for the tip on leaving the connection loose, sounds like you could minimize it fairly well doing that. As you stated in your own response though, there are reasons for attaching another, but I don't think it's limited to fruit or other additives in secondary. The whole point is to do all stages in one vessel, right? Simplify. You get more stuff falling out of suspension in secondary and lagering if you do that in conical... I plan on it. So, I want to capture and remove that before going to keg. I really don't think that's a rare desire. Commented Apr 5, 2015 at 2:27
  • After reading your suggestion, I thought of another way to eliminate the glug... Fill the bulb with sterilized water. I think both methods would have their merits, I'm sure many of us don't wanna "water down" or beers, but I think it'd be insignificant. Commented Apr 5, 2015 at 2:33
  • The fast ferment bulb space is about 1L actually. The problem I ran into recent was I had so much trub I had to dump about 3L total. That was my fault for not filtering out more of the hops/hot break. I think you are right though that the total oxygen relative to the remaining airspace (about 3G) is quite low and from a taste perspective I don't think it had a huge impact and this was a worst case scenario. Commented Apr 21, 2016 at 14:53

Main issue in my conical the amount of trub on the angle towards the trub jar. I waited 3 days to dump and jar was filled. After 2nd dump a thinner layer of the trub was still on the Angled sides. Trub jar now is roughly 1/3 full but I'm thinking I'll leave the yeast clean up after itself and wait a few more days. I'm seriously trying (against the norm) like open I g fermenter and slowly scraping the Angled sides with a plastic spatula. Hey, if it works, cool if not, well live and learn.

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