Question about BBT design

[dfalken]

What is your opinion/experience on a BBT with a 70 degree cone bottom? Please explain any advantages/disadvantages vs a dished bottom BBT you know of. I am having a disagreement with someone about this topic and would like to hear others' experiences.

Thanks in advance.

[gitchegumee]

I must be missing something. Why would you ever have a conical bottom to a BBT? For What purpose? Dish bottom is the overwhelming majority of BBT or serving tank.

[dfalken]

I must be missing something. Why would you ever have a conical bottom to a BBT? For What purpose? Dish bottom is the overwhelming majority of BBT or serving tank.

I never said it was supposed to make sense and I know why it is not a good design but I am just looking for others' supporting experiences to prove my case.

[Buster]

We have often times used a conical fermentor as a BBT with out any issues and sometimes still do. We put a carb stone in place of the racking arm and pull directly off the bottom.

Matt

[dfalken]

We have often times used a conical fermentor as a BBT with out any issues and sometimes still do. We put a carb stone in place of the racking arm and pull directly off the bottom.

Matt

Thanks for your input Matt. My main concern is that the beer in the cone below the stone won't get carbonated directly and it will take time for it to get carbonated from head pressure. How long after carbonating in the conical did you package the beer? I would assume that if you wait a couple of days there would be no problem, but I think that it would take longer for all the beer in the tank to reach the desired CO2 volumes in a conical tank than in a dish bottom BBT.

[lhall]

I would think the disadvantages would be:

1. Cost - I would think it would be cheaper to spin out two dished tops and bottoms than to form a cone - maybe not
2. Hydrostatic pressure - a coned tank is taller than a dished bottom
3. Space -

[william.heinric]

The only advantage I see to dedicating a CCFV to BBT duties is that if you're going to leave your beer unfiltered, and you have the time to let it sit cold to floc the crap out. Otherwise, dish seems to be much more efficient.

Bill

[Buster]

We have done it many times and carbonated beer overnight. The main reason we did it was because we needed to have several different styles of beer ready to package and all of our brites were tied up. We were able to use a 90 bbl FV as a brite, fill it with brite beer one day, package it the next and fill it with wort the day after. The fermentor was only out of service for 48 hours and we fulfilled all the necessary orders. I am no expert on the subject but as far as your concern of CO2 absorption goes, that shouldn't affect the beer in the cone. I am pretty sure once you start injecting it into the tank and the co2 dissolves into solution, it spreads equally throughout the beer. Anyone care to comment/correct me on this?

We still actually use an old 30 bbl FV as a brite to this day. Bought it back in the mid 90's and didn't realize/know how crucial fermentor shape was. It is a really tall narrow fermentor with a short cone. The yeast performed poorly in it, so we ended up turning it into a brite tank and it works great. Because it is tall and narrow it actually carbonates rather quickly. We can bring it up in a matter of 6 or 7 hours to 2.58 - 2.62.

Matt

[dfalken]

Thanks for the details Matt. What I've heard is that you can get uneven carbonation in a fermenter because the beer above the cone that gets hit by the bubbles carbonates faster than the beer below it that has to carbonate basically by osmosis. That beer is carbonating no different than if you were carbonating just by head pressure instead of using a stone and we know that takes much longer. Since you were carbonating from the racking arm, there isn't that much beer below it so maybe that is why you didn't have a problem.

[gitchegumee]

Ah, so I guess I am missing something. You aren't designing a BBT, but rather using another tank as a temporary solution? In that case, you could use a CCFV as BBT if you do it right. Like using a low port for your carbonating stone. Remember that BBTs almost always have carbonating stones above some of the beer they carbonate. The whole of the bulk DOES get carbonated thanks to currents inside the tank. Either due to cooling from the jackets setting up convection currents or carbonation input doing much the same with buoyancy. Either way, beer does get carbonated. And usually quite fast--at the worst overnight. Maybe not the best vessel, and certainly more expensive, but it can be done. Kinda like using a dish-bottom vessel as a fermenter--yes it can be done. No it's not ideal. If you were designing a BBT, then stick with dish.

[dfalken]

Ah, so I guess I am missing something. You aren't designing a BBT, but rather using another tank as a temporary solution? In that case, you could use a CCFV as BBT if you do it right. Like using a low port for your carbonating stone. Remember that BBTs almost always have carbonating stones above some of the beer they carbonate. The whole of the bulk DOES get carbonated thanks to currents inside the tank. Either due to cooling from the jackets setting up convection currents or carbonation input doing much the same with buoyancy. Either way, beer does get carbonated. And usually quite fast--at the worst overnight. Maybe not the best vessel, and certainly more expensive, but it can be done. Kinda like using a dish-bottom vessel as a fermenter--yes it can be done. No it's not ideal. If you were designing a BBT, then stick with dish.

Thanks Philip, totally agree with you, it can work but it is best to avoid it. Yes there is some beer below the stone in a dish bottom BBT but the surface area compared to the height of that beer is much larger than inside of a cone especially if the stone is high up in the cone or above the cone and that is what adds extra time to carbonation. It also adds to the price of the tank, takes more room inside a container and in the brewery and for no good reason.