I've used a number of cartridge filters on various beers. The pro is that you can get clear beer. Here's some cons:
- You need to keep track of all the parts. Missing one small thing like a gasket will cause the whole thing to fail.
- Cartridges don't all fit correctly and can cause leaks.
- If you have a lot of suspended particles (like cocoa powder) you will need to filter the beer with multiple grades of filters or it will get clogged.
- You will lose some beer every time you filter. If you filter multiple passes...well, you know...
- Reusable cartridges sounds nicer than they are. They are not easy to backflush and store. I can go more into that but it can get long and drawn out...
- You are not guaranteed to filter everything. The biggest thing that was not removable was pectin haze. I went down to 0.5 micron on various things like cider and fruit beer and there are some things that just will not clear. Your "normal beers" will probably clear just fine, but most of those clear just fine with the alternatives. The key thing to take away is you can still have cloudy beer after using clarity agents, cold crashing, and filtering.
- It really is a pain to use these systems. The hoses flop around, the cartridge holder really needs to be in a bucket in case it leaks. If a hose moves there's a possibility that it will rotate just enough to cause the cartridge holder to leak. You can't over tighten because the cartridge holder is made of plastic. If you under tighten it leaks. Even when pushing with CO2 it's best to elevate the primary keg and there can be a lot of back pressure preventing flow through the filter.
- Troubleshooting is a PAIN! If something doesn't work you have to check all your tubing, make sure you put them in the right in/out holes on the cartridge holder. It could be a crimped or blocked hose, it could be a clogged cartridge, maybe the cartridge was slightly off centered when you installed it and tightened down the lid and now it's either not filtering or it's leaking. Maybe your CO2 pressure is too low, or it could be that your primary or secondary ball lock connects are blocked. So...this might not sound bad...if you're not a total idiot and hook everything up correctly nothing can go wrong...right? Well the problem is that when you do have a hiccup, you have a filtering system full of beer. Troubleshooting it means you will have to dump all that beer...where? Back in the keg? Down the drain? In a glass to drink flat? The alternative is that you do a wet run with some water. What this means is that there's more work because now you have to push water through a keg before beer...then when you're done you'll want to drain out that water and push with some beer...most likely losing some of that beer in the process (I don't want water mixed in with beer so the first couple of seconds get dumped out).
- Filters aren't cheap, and neither is losing beer (some of it is left behind in the filter holder).
- The process is slow if you want it to be effective. Push too fast and it won't filter as well. But it takes forever to filter through the smaller micron and sub-micron filters.
- You will lose some flavor. I suppose it depends on the recipe and your palate, but I noticed a loss in flavor. This is especially the case when you add things like spice, fruit, or chocolate to the beer. You added it, now you're taking most of it back out. I haven't filtered a dry-hop beer so I can't speak on how it effects hop flavor or aroma.
- It's more stuff to store and replace, because now you have extra hoses and stuff. If you have to replace hoses on your wort chiller, auto-siphon, kegging system, etc...this is just one more thing to add to the tally. And you had better remember to unscrew everything to let it air dry.