Sterile Filtration Info

If you are interested in sterile filtration, here is a very informative site:
http://www.cfsfiltration.com/www.cfsfiltration.coms/info.php?p=7

To remove yeast, you want a 0.5 micron filter.

Note rule #1:
"For Sub Micronic FIltration always use a plug in or plug on style."

That means do not use a standard DOE (double-open end) filter to remove yeast. I wish I knew this 6 months ago. I bought a Pentek housing and a Flowmax filter... and experienced leaks and poor seals.

Note that all of the commercially-offered homebrew filter setups use DOE filters and housings.

Now I have a 222 O-ring filter and a nice polypropylene housing; no leaks. Both are from McMaster Carr for $90 total. My next upgrade will be to a Polyethersuphone membrane filter.

Also, many beer filter websites would have you believe that you must filter in stages. Not true. You can filter a keg of brew in one pass, through a 0.5 micron filter with no problems. Takes about 15 minutes, with 15 PSI on the supply side and a pressure relief set at 10 PSI on the receiving keg (5 PSI differential) - these values are arbitrary.

Interesting read. Please post the McMaster part numbers you're using.

44095K32
Polypro Filter Cartridge w/222 O-Ring End Cap Closed End, 10" H Cartridge, 0.45 Micron Rating
In stock at $33.33 Each
[This was a temporary fix - highly recommended that one uses a $90 Polyethersuphone filter]

44195K12
Polypropylene Water Filter Housing for 10" Height 222 O-Ring Cartridge
In stock at $45.54 Each
[made by Keystone Filters - their page is http://www.keystonefilter.com/html/house1_b.htm ]

That filter cartridge is quite pricy. How many brews do you anticipate filtering with a single cartridge?

The one I have now is pleated... I think the manufacturer does not recommend backwashing, but I'm backwashing it after use with fresh water for 20 mins, then a final backwash with star san. I'm really not sure when I'll retire it, but I'm guessing 5-10 kegs ??? I'll probably go by smell and sight - if it smells clean and looks clean, I'll still use it.

The $90 ones, especially if you go for the stainless reinforcements, can be repeatedly cleaned and re-used, according to literature.

But keep in mind that 'pricey' is a relative term; if you're comparing a $34 or $90 cartridge that actually works to a $5 or $10 cartridge that doesn't actually work, then you're comparing apples to oranges.