Filtration inline carbonation
I am wondering if anyone out there has carbonated beer while filtering through a plate and frame filter.
Usually we wait until the beer is filtered into the serving tank, then cooled to about 39F and then carbonate it through a stone apparatus by circulating it. The circulation process takes roughly 2 hours. The problem is waiting for the beer to cool back down to the 39F range so that I can carbonate it sufficiently. I am trying to speed up the process by carbonating inline if it is possible. There are severl concerns. 1) The beer temperature inside the filter. 2) Tank pressure ratings. 3) filter pressure ratings. The tanks can hold about 25LBS safely and the filter will run safely at about 2BAR or 30 LBS. What about keeping the temp low with sufficient throughput? Will the higher throughput mean that I have to increase my pressure? Will it also mean poor filtration?
If anyone can make any suggestions about doing something similar I would greatly appreciate your input.
No problem carbonating pre or post filtration, using any sort of filter. However thekey to effective solution of CO2 is the temperature. 39 deg F is really too warm, and you will start to get gas breakout, especially of high CO2 beers, at these temperatures. Look at the Meheen manufacturing website for a CO2 solubility vs temperature curve to confirm.
Ideally you should be filtering at less than zero C (32 F if you prefer). This gives a couple of advantages. Firstly, if the beer has been held at less then zero for a few days, the beer will be less prone to producing chill hazes in the pub, or permenant hazes in the bottle or keg over a longer period of time. Secondly, the CO2 will dissolve much better.
The problem with pre filter carbonation and / or warm filtration and / or low pressures in th efilter is getting gas breakout, which will create pin holes in the filter bed which will allow haze material, yeasts and bacteria to pass through, so reducing the shelf life of your beer, and perhaps allowing immediate haze to pass through, making it unfit for sale (customer opinion - not actually harmful of course)
If you get / keep the beer colder, you will not require such high pressures to achieve the same degree of carbonation (as well as the previously mentioned clarity improvement)
I am surprised at the low pressure tolerance of the filter. I don't know what sort of material it is made from, but I would have expecte polypropylene of stainless to be be able to cope with 5 bar (approx 65 psi) without any problem. Our admittedly rather larger filters cope with 6.5 bar before we are liable to suffer leaks or damage.
Pressure off the filter should need to be more than 15 psi, i.e. your tank pressure should be approx 15 psi. If your CO2 content is low, lets say 3 grammes / litre (1.5 v/v), you could operate BBTs at a lower top pressure. In fact you might need to, purely to prevent CO2 pickup
You need to chill your filter down with cold water, preferably in a recirculation system prior to introducing beer. " deg C is probably the best you could achieve safely.
Hope this helps
Yes Filtering in combination w/ carbonation works well.
However, (as Dick said) I am chilling beer to 33f 4-7 days prior to this and also chill the filter down w/ cold water after heat sanitizing. Canít you chill the beer down earlier? It sounds like you are filter beer at fermentation temp. If you have no jackets on you FV's how about running the beer though the wort chiller berfore filtration...do you have glycol at chilling on that?
I use a pinpoint carbonator, which is the same as installed after my wort chiller. I put it directly on the filter output and run the hose to the tank from there. This gets me very close to serving right after filtration is done. Only 1/2 to 1 hour of using the tank stone and its to the bar!
Also, Again as Dick said, your beer pressure should be greater than the co2 pressure applied. I run the fermenter tanks at 15 psi and the server & co2 in at 10. The filter can take more but my tanks cant. My fermenters are about 20 feet above the servers so 5psi achieves enough Pdiff. (keyboards need that weird delta sign!)
If your tanks can handle higher pressure you should be able to fully carbonate without the tank stone. Or you could krausen and skip this, but again you need to chill your beer.
I'm not sure I understand how I gave the impression beer pressure should be higher than CO2 pressure (or is it my interpretation ??), but never mind. During in line carbonation, or indeed tank carbonation, the CO2 pressure has to be slightly higher than the beer pressure, otherwise the beer will try to run back into the CO2 source. Use of a stone is better providing you can keep the wretched sytem clean and sterile between use, as the finer bubbles producedwith one dissolve faster than the coarse bubbles produced without. The tendancy is to produce more fob if a stone isn't used as bubbles remain at the top of the vessel, and collapsed foam = haze.
Never mind the weird delta sign, how about one that can sensibly correct my lousy typing ?