Carbonation help wanted!

[Horsepoorx2]

I just switched over to 5.7 unitanks (from my 1/2 barrel nano fermenters). I had previously crashed, carbonated and bottled from the smaller tanks, and had my product precisely where I wanted it. It had a nice, thick head and good retention. When I switched over to the unitanks, I placed about 4.2 barrels of product into the new tank (all that I had on hand), crashed it, and carbonated it to (what should have been) the same 3.0 + volumes of CO2, based on the temperature and pressure. For the small vessels, I was filling them, crashing them, then putting on the gas and rocking them. The new vessels have a carbonation stone, located just above the point where the cylindrical and conical portions of the tank meet. I had the tank chilled to 34 degrees, and had 15 psi on the stone. (It was there for a couple of weeks, because I still had other things to get in place before I was ready to bottle.) While bottling, everything looked "normal." The product appeared to have plenty of gas. However, when I open one, I get about half of the head that I had with the batches I carbonated in my smaller tanks. It is not thick, lacy and creamy like the previous batches, and disappears quickly. Is this because my tank had too much head space? Thankfully, I only bottled about 1.3 barrels. I want to salvage what I have left. I am thinking of transferring it to smaller tanks and repeating what I had done before. I'm a little bummed right now.

[Hazell]

How is the perceived carbonation on your palate?

As I'm sure you are aware, foam has a lot of different factors. Carbonation is just one of them. Has anything else changed in your process?

Having large headspace should not make a significant difference but it's possible you have lost some foam potential on the tank walls. When you pressurise with a carbonation stone, it will form foam within the tank that can stick to the walls. Have a look inside the tank when you have emptied it.

Do you or any other brewers you know have a device to check in-pack CO2 with? We use a simple pressure testing unit and a digital thermometer. You could compare an old bottle with a new one and see how much the carbonation has droppped by.

Carbonation stones are good for passing CO2 through beer but once the tank is up to pressure, it will be a slow process for the CO2 to dissolve from the headspace. Only small amounts of CO2 will be entering the system at that stage. Agitating the tank speeds it up as you did with the smaller tanks. You could also slowly pass CO2 through the carb stone with your top pressure venting at the right pressure for the CO2 you want at X temperature. This can strip hop aroma so should be a last resort.

I hope some of my ramblings are helpful

Cheers,

[GlacierBrewing]

I just switched over to 5.7 unitanks (from my 1/2 barrel nano fermenters). I had previously crashed, carbonated and bottled from the smaller tanks, and had my product precisely where I wanted it. It had a nice, thick head and good retention. When I switched over to the unitanks, I placed about 4.2 barrels of product into the new tank (all that I had on hand), crashed it, and carbonated it to (what should have been) the same 3.0 + volumes of CO2, based on the temperature and pressure. For the small vessels, I was filling them, crashing them, then putting on the gas and rocking them. The new vessels have a carbonation stone, located just above the point where the cylindrical and conical portions of the tank meet. I had the tank chilled to 34 degrees, and had 15 psi on the stone. (It was there for a couple of weeks, because I still had other things to get in place before I was ready to bottle.) While bottling, everything looked "normal." The product appeared to have plenty of gas. However, when I open one, I get about half of the head that I had with the batches I carbonated in my smaller tanks. It is not thick, lacy and creamy like the previous batches, and disappears quickly. Is this because my tank had too much head space? Thankfully, I only bottled about 1.3 barrels. I want to salvage what I have left. I am thinking of transferring it to smaller tanks and repeating what I had done before. I'm a little bummed right now.

Hi James,
I would have some concerns with my carb stone in that location. Having the stone that high up in the low volume of beer might not give all of your beer the carb treatment you want. I would get additional fittings (if you don't already have them) to allow you to connect your stone to the lowest port on the tank. I'm thinking of a "T" with a valve on the side and the stone in the end. Hopefully you have the means of taking your beer off of the yeast before you do this. It has been my experience that 35 might be a touch warm for carbonation (although I have done it many times!). Ideally, get the beer down to around 29-31F. You should be able to get the carbonation levels where you want it in a few hours. The warmer the beer the longer it takes to carbonate. Lastly, get yourself a Zahm & Nagel CO2 tester. Worth it's weight in gold! Your palate just might not be the same every day. But the Zahm's readings are!
My two cents.
Prost!
Dave

[Horsepoorx2]

I appreciate the great info and support from both of you. The perception of carbonation on my palate with this new batch matches it's appearance. It's pretty flat. The whole character of the brew is different. Other than using the larger (jacketed) tanks, carb stone, a glycol chiller, and having that head space, I cannot think of anything else that changed. Here is what I did when I began carbonating. I had a pressure relief valve (spring and steel ball type) at the top of the tank. I had it set (I thought) such that it would vent if the pressure got to over 15 psi. I charged the head space with 15 psi before I began carbonating with the stone because I thought I read somewhere that I might get too much foam if I just hooked up the stone and let it bring the pressure up. Three bad things happened over the next couple of days. First, it turns out that the (bargain) pressure relief valve that I got from McMaster-Carr was incapable of holding back ANY pressure, even with it cranked all the way down. Over the first night, I lost all of the CO2 from the 20 pound tank I was using, and the pressure in the unitank bled down to 7 psi. I took out the valve and replaced it with a ball valve, and relied on the regulator to control the pressure. This next time, it turns out I had a small leak in the lid. There went gas tank number 2 and again I lost pressure in the vessel. I fixed the leak and reconnected the gas, and this time it all held just fine. I am thinking I probably got tons of foam each time I lost pressure in the tank. I took samples through a pigtail and they were so foamy I was concerned I had too much carbonation, so my actual results surprised me. Wrt comparing in-pack pressure, I no longer have any of the old bottles. I sold what I had on hand. Is the pressure testing device you mention the type that taps through the cap? If so, I am using 750 ml swing top bottles and would need to come up with something different.

Thanks for the tip on the carb stone location. I can totally do that - if not this time around, certainly next time. I could put a tee on either my racking arm (located 1/3 of the way up the cone) or on the bottom drain. I dumped the spent yeast, so I think I should be OK. I am using carb stones I bought from GW Kent, catalog #85-50. But I seem to recall I could use their pico carbonator - which I also have - for my size vessel. It would fit in a tee easily. I will try to get the brew colder. That brings up another issue - with which I am dealing today. The jacket of the tank does not cover the cone. Now that the remaining product is is mostly in the cone area, the coldest I can get it is 38 degrees, and I am wondering if temperature stratification is also a factor. I have some copper tubing that I am going to wrap around the cone and see if I can get it down to the 29-30 degree range you speak of. Thanks again for all of your help! Sorry for the "Tolstoy" response!

Cheers,

James

[GlacierBrewing]

I took out the valve and replaced it with a ball valve, and relied on the regulator to control the pressure.

Remove that ball valve and get a quality pressure relief valve! Basically you have just made a pressure bomb out of your unitank.

Is the pressure testing device you mention the type that taps through the cap?

I'm talking about this device: http://www.zahmnagel.com/Products/SE...0/Default.aspx

Bummer about no jackets on the cone. Make sure to insulate the livin' bejessus out of the copper coils after they are on the cone.
Good Luck!
Prost!
Dave

[Brewer Dan]

We had a very similar occurance with our first batch of beer on our scaleup. We had gone from a 1/2 barrel system to our 20bbl system.
We did the carbonation the way we had always done it... head pressure, at 34F over a week at pressure, when we bottled, it turned out pretty flat. (all of us here at the brewery actually liked it better that way to be honest, but everywhere we took it we were told it was too flat.) We ended up buying a meheen tank management system (not cheap, but well worth it). http://www.meheen-mfg.com/carbonation.html. The only downside i can say about the system, if you leave it in maintenance mode too long, you do lose some aroma, and it burns plenty of CO2. But since having that system, we haven't had a problem with our carbonation. Hope that helps a bit.

[Hazell]

Good to hear you've found the cause mate.

That Zahm unit looks handy. We use digital gehaltemeters and they cost a fortune!

[Matt Dog]

Dont go hooking up a carb stone to a racking arm. A racking port will work, but if you have a racking arm that extends into the tank you'll just create a bunch of big bubbles glugging through your beer. The stone needs to be in the beer. Every stone has a cracking pressure and if you have a check valve then that adds to the cracking pressure as well. Also the height of the beer adds to the pressure needed to get the stone to start bubbling. You cant simply go by a carb chart that is designed for equilibrium pressure and temp. The best thing to do would be to listen to the tank (press your ear against it!) gradually turn up the CO2 till you hear it going into the tank. As the pressure in the tank rises you will have to gradually bump the pressure up on the regulator. You dont want it rushing in stripping out all your aroma and creating foam but you want a good steady flow. You can also listen to the regulator. At some point if you want to carb in a short time you will have to SLOWLY bleed some pressure off the top. Also most of the pigtails wont give you a good pour. If you dont have a Zham (you should) get a 120$ perlick pigtail (the one with the tiny ID tubing and all the turns not the larger ID with fewer turns). You can pour a perfecy glass of overcabonated beer with one of those. That will at least give you a good mouthfeel test. You can also add about 5 or 6' of 3/16" beer tubing to your current pigtail and put a home brew picnic tap on the end for a good pour. Carbing is tricky business and every situation is slightly different. Do yourself a favor and get a Zham so you can know what your doing is working or not and have the ability to adjust it.

[Horsepoorx2]

Hi everyone. Thanks for all of the great input! I did get coils around the cone yesterday and the tank temp dropped 4 degrees. I have another 4 to go. We'll see . . . If it does not work, I will have to depressurize this tank - slowly, I am assuming - let it go flat and start over in my smaller vessels. If I try to transfer it now, I am concerned I will get way too much foaming. Any experience or suggestions in case I have to go this route?

@ Dave: "Remove that ball valve and get a quality pressure relief valve! Basically you have just made a pressure bomb out of your unitank."

I understand the concern, and believe me, I am wary. Do you have a link to, or the name of a good device?

@ Matt: Will I have the "large bubble" issue if I insert the carb stone in a T upstream from the elbow I have at the bottom of the tank? That bottom port and racking arm are my only options other than where the stone is now. thanks for the tip on the pigtail. I currently have the $95 job from GW Kent. You're right. Doesn't work worth a darn. I will try the beer tubing fix in the short term.

I will look into the Meheen tank management system and the other components suggested here. Thanks to all of you! This is soooooo much more productive than a blind internet search for what I need. That's like turning over rocks in the dessert.

[GlacierBrewing]

@ Dave: "Remove that ball valve and get a quality pressure relief valve! Basically you have just made a pressure bomb out of your unitank."

I understand the concern, and believe me, I am wary. Do you have a link to, or the name of a good device?

Try GWKent, http://breweryparts.com/index.php/fi...ief-valve.html

Prost!
Dave

[biosonik]

The "T" idea may work better than the racking arm but not much. Tried this already. You are basically only affecting the beer inside the t and anything that re-enters the tube while the beer is displaced by CO2. Ideally you want to disperse millions of tiny bubbles any direction they may please. With the T you have a garden hose type situation when what you need is a sprinkler!
Also when you try to rack out of that valve on the side of the T the stone will cause foaming while the beer passes thru it... Put a stone where the racking arm is and blow yeast off the bottom? Or weld in a ferrule in the right spot. That shouldn't cost too much. Just find the right sanitary welder.

[Horsepoorx2]

The copper coil I installed is working well enough. It was a bear to get on with the tank upright, and no flanges against which I could wind it. I insulated it. After I empty this tank, I am going to remove it the coil, have flanges welded onto all three of the vessels like this that I own, and do a proper job of installing coils. Nevertheless, I got the temp down to 32 degrees. I plan to transfer the remaining 2 BBL+ into 1/2 BBL vessels and carbonate and bottle from there as I did before. At least I can salvage the rest of this batch. (My friends and I will drink the "rejects." ) Once I empty this fermenter, I am going to take it and the other two I have to the fabricator that made them for me and have a dedicated carb stone ferrule welded in a new location near the bottom of the cone, and cap the old port. Since these are unitanks, the stone will be in the tank while the brew is fermenting. Do I need to be concerned about yeast settling on the stone and clogging it up? I would assume I need to have the stone high enough up the side of the cone so as to remain above the lees. Is that correct? How high is best? 1/3 of the way up? At the level of my racking port? Thanks to all of you for the marvelous help. I love this forum!!!!

[Ericbiere]

How is the perceived carbonation on your palate?

As I'm sure you are aware, foam has a lot of different factors. Carbonation is just one of them. Has anything else changed in your process?

Having large headspace should not make a significant difference but it's possible you have lost some foam potential on the tank walls. When you pressurise with a carbonation stone, it will form foam within the tank that can stick to the walls. Have a look inside the tank when you have emptied it.

Do you or any other brewers you know have a device to check in-pack CO2 with? We use a simple pressure testing unit and a digital thermometer. You could compare an old bottle with a new one and see how much the carbonation has droppped by.

Carbonation stones are good for passing CO2 through beer but once the tank is up to pressure, it will be a slow process for the CO2 to dissolve from the headspace. Only small amounts of CO2 will be entering the system at that stage. Agitating the tank speeds it up as you did with the smaller tanks. You could also slowly pass CO2 through the carb stone with your top pressure venting at the right pressure for the CO2 you want at X temperature. This can strip hop aroma so should be a last resort.

I hope some of my ramblings are helpful

Cheers,

Hello Hazell,
I'm here in the south France where Co² management is quite an issue because our kegs are stored in the sun & the bars keep them at best 30°c. Just to mention part of our situation - (we do only kegs)
I'm surpised that you say the gaz liquifies more slowly at higher pressure. I think its the oppisite. I would have thought that at 1°c or less & at a higher pressure the gaz would not break out as much and not foam out the Co² by the time it gets to the top???????????????
I know that if it breaks out on the surface its lost.
You de-gaz by blasting & agitation or simply letting off the head pressure & it foams out.
Well?
Eric