Conical and secondary

Hi everyone, my question has to do with secondary fermentation and all the articles that I have been reading the past 2 weeks. I have 2 conical fermenters and as I have been reading they are excellent for secondary, because you can remove the sediment without the need of transferring to a separate fermenter, thus not having to worry about oxidation and contamination.

Here is my question, when you open the bottom valve to remove the sediment you have to remove the airlock from the top or the tube (if you're using a hose barb) because you don't want the sanitized solution to enter the fermenter by reverse suctioning. In that case though, by opening the valve and lowering the volume of the liquid (without the above mentioned airlock) don't you also allow oxygen to enter the fermenter?

Thanks in advance!

JohnB said:

by opening the valve and lowering the volume of the liquid (without the above mentioned airlock) don't you also allow oxygen to enter the fermenter?

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In a very general way, yes. But that is far from the whole story. If you feel the need to stop the possibility, you can just run some low pressure CO2 through the same opening to maintain positive pressure.

When you're removing yeast from a conical, you're only concerned with the spent yeast. This is the thickest portion of the the yeast cake, which is the very bottom of the cone. You'll stop when you see a slight color change to creamy, fresh looking yeast. You don't just open the valve and let it just flow, you try to maintain a slow flow to prevent making a hole in the yeast cake. The center of the yeast cake will fall faster than the sides, in the same way that you see when milling grain.

So, the amount of yeast that's dropped will be pretty small compared to the whole. You do this a little at a time over 4 or 5 days and you'll start to see very thin runnings, which means most of the yeast is gone.

I like the setups where a piece of 1.5" stainless pipe is attached to the come valve and allows the yeast to settle into it. A couple of days past primary, just close up the valve, remove the piping and a large portion of the yeast is removed. Repeat and you have both a clear beer and a nearly aseptic method for repitching. [Pro Tip: one foot of 1.5" holds almost 12 ounces]

Well understood! Thank you Brewfun!

One more question please: in Beersmith I see a recipe that says, primary time fermentation 4 days at 19C, secondary 14 days at 19, aging 30 days at 15C.
Since I have built a glycol cooling system (for the fermenters) do you think I would be able to use the conical for aging as well? In the event that forced carbonation is used to keg I suppose it is possible, but if I am looking to use table sugar (the recipe says 190 gr. for the whole batch) would I be able to pour in the sugar (after secondary) in the fermenter and leave it for 30 days and then bottle it? I am worried about the making of the Co2 in the fermenter and then loosing it during bottling.

P.S. Thank you for the pro tip and the idea of 1.5" attached stainless pipe!

JohnB said:

Since I have built a glycol cooling system (for the fermenters) do you think I would be able to use the conical for aging as well?

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Yes. The point of conicals is to have just one vessel do multiple jobs. This is whay they're called "Unitanks."

Would I be able to pour in the sugar (after secondary) in the fermenter and leave it for 30 days and then bottle it? I am worried about the making of the Co2 in the fermenter and then loosing it during bottling.

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It depends on if the fermenter is made for pressure. Most aren't, so the CO2 just leaks out or comes out the airlock.

P.S. Thank you for the pro tip and the idea of 1.5" attached stainless pipe!

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You're welcome!  8)

The company that makes the conical says it is a max pressure of 5 psi (shouldn't though go above 2-3 psi) and it is suitable for pressurized transfers (not that this is our topic here) so I will talk to them to get more info. But let's suppose it is fine for aging with table sugar, any ideas how I bottle after the aging is finished? Meaning that I would have to allow air coming from the top in order to bottle. Wouldn't that mean that the present Co2 will escape after I begin the transfer or would it be too little and would be replenished in the bottles and/or kegs after the transfer (since sugar would be present).

You'll want a counter pressure transfer to bottle. But, you have a larger issue and that is that the conical is not designed for carbonated beer. You'll need 10 to 18 psi to achieve carbonation and maintain it.

OK, so when BeerSmith says to age e.g. at 6C for 30 days does that mean that I have to add the sugar to start the aging process or I can add it during bottling? In other words, can aging (after a two stage fermentation) take place without adding any sugar?

In BeerSmith, "ageing" is the process of carbonation and conditioning the beer. It doesn't have to be that long, but it is defined by being in the keg. It's really done when you say it is, once it's carbonated, which is what the late sugar is for.

Seems to me that the advantage of a conical is that you skip the secondary step, but you still have to deal with the hassle of bottling.  The vessel is made for fermentation pressure, not carbonation pressure.