View Full Version : Filtration

10-31-2003, 09:27 AM
I'm currently using a small horizontal leaf D.E. filter. I use standard grade DE, Hyflo, and Fibracell which is a cellulose product. My procedure is to precoat with a small amount of fibracell which has the smallest pore size then standard and then dose with mainly hyflo and a little standard mixed in. It seems everyone has a different procedure when filtering and most just say "Thats how I was taught" Does anyone have a firm grasp of the mechanics of filtration and why you should use particular Grades of DE for each stage. My reasoning has always been coat from the smallest pore size to the largest to maximize flow. Also does anyone have experience with Perlite or PVPP products.
Any ideas suggestions welcome.

10-31-2003, 02:14 PM
After using DE & celulose for ten years I switched to Perlite. I was using Celatom FW-12 and now swear by Perlite 27M (sometimes called grade 7). Perlite is lighter than DE so you use the same volume as DE not the same weight. The perlite seems to stay in suspension in the dosing tank better than DE. I do a normal precoat (no celulose!) and then filter on. Personally I've had better luck in using one grade of DE. I've tried different blends in a wide range of beers with mixed results. My policy is KISS. Try filtering with straight Hyflo (after a fibracel/de precoat). Are your beers being packaged or draft only?

David R. Pierce
BBC Brewing Co., LLC

dick murton
11-02-2003, 02:06 PM
I have got a load of info I can send you on filter operations if you wish - drop me your email adress and I will send some stuff on use of perlite, ordinary KG, PVPP and silica gels.

Crudely, precoat with perlite at normal filter flow rate to form a filter bed about 1.5 mm thich, then use body feed grade KG to form a secon precoat. Then use the same feed for the bodyfeed. The finer the body feed, the faster the pressure differential rise, and shorter the filter run length, but the clearer the beer should be, and the coarser the body feed, the slower the differential pressure rise but potentially with slightly higher hazes. The key is actually getting the beer cold, minus 1 or 2 deg C for 24 hours plus prior to filtration and maintaining it at that temperature throughout filtration. The haze materials are then filtered out instead of redissolving.

You will never produce a sterile beer with KG filtration - you need a second membrane or absolute pore size depth filter post KG filter for that.


Larry Horwitz
11-25-2003, 05:59 AM
Here is name and number of my guy at World Minerals
He knows more about DE than anyone i've ever met

He'll give you a great talk about how to optimize your filter

Niels Mastrup

Good Luck!

12-06-2003, 10:58 AM
I have to agree with beertje46 as the KISS method pays off. I've struggled, and I do mean struggled, through the filtration process using a DE filter and have found that using a straight grade for all phases is the best for me. I usually filter 30 barrels in about 1 hour in conjunction with a plate filter on the outlet of the DE running at about .3 microns. This is a drastic change from spending a complete day on filtering. I currently use Hyflo only, but do mix in about 20% Cellulose on the pre-cake. seems to help in the clean up phase. Also, looks like there is a lot of good information posted from the others to check out and I will be doing so myself. Thanks all.

12-12-2003, 12:26 PM
Another vote for KISS.........
I have a small horiz. "DE" filter. In the past I have
just used Hi-Flow DE. Approx. 14 lb's DE for 7BBL's filtration or 21 lbs for 14 BBL's.

I recently converted to Perlite. I am using the same volume of filtration material (about half the weight of DE) for each filtration.
So far all filtration has been un eventful...a very good thing.

Currently I am using 50% 3 micron and 50% 7 micron. I will be going to 100% 3 micron when the 7 is gone. I also agree with Dick on getting the beer as cold as you can 24 hrs before filtration. I shoot for 35-36 degrees F.

Any other Perlite converts out there????

Larry Horwitz
01-14-2005, 07:15 AM
Perlite has no secondary or terciary pore structure, so you can filter more beer with de. I.E. you can get more beer through your 2m filter faster with less media if you use DE. BTW I'd keep using a dust mask with my perlite if I were you...inhaling perlite is just as bad as inhaling de

01-14-2005, 10:37 AM
This is an interesting thread and I can't resist chiming in. D.E. filtering of beer can be very challenging at times. Unless you select a grade of D.E. that is "low iron", it can be a significant contributor of beer soluable iron which can have a very great impact on the shelf life and ultimate clarity of your product. Keeping it simple is definately the way to go, however don't fall into a trap of overdosing D.E. in order to get good throughput. Using a cellulose pre-coat on a leaf-type filter can speed up the process, stabilize the filter bed and reduce the total amount of D.E. required. Rates of 2 pounds per barrel (as were mentioned) are rather excessive and can lead to flavor issues and stripping hop character from the beer. Once you find a dosing rate that is successful all of the time, I would suggest doing some work to trim back the dosing rate to an optimal (minimal) level.

Anything that can be done in the cellar to reduce the yeast load going to the filter would pay off in the form of reduced D.E. usage. Also, good brewhouse practices and malt selection can reduce excess protein and tannins that foil smooth filtration.

I would be interested in hearing anyone else's comments along these lines.



Larry Horwitz
01-14-2005, 10:50 AM
We've been using celite's 512z. It's 0.5 darcy perm. and has a reduced mineral and iron content. no issues with "inky" flavors associated with regular de.

Larry Horwitz
01-14-2005, 10:52 AM
by the way....don't mix grades of DE. manufacturers say that they have taken time to grade it out, and if you mix you are actually messing with the "torturous path" and building a less stable cake...it won't bridge right and may fall on itself.

01-22-2005, 08:08 PM
Larry is right about not mixing grades of DE. If you mix a fine DE with a coarse DE then one just filters the other out. But it is normal to re-circ. 1/3 coarse COMPLETELY onto the screens and then follow up with 2/3 fine. So I guess a better way to put it is different grades of DE should never be present simultaneously in the slurry. The dosing DE should be matched to the particle you're trying to remove; i.e., use fine for protein and coarse for yeast and something in between for both--you're rep can help you select the right grade.

As far as iron goes many precoat in DA water and reject after the cake is formed. Then try and get away with as little DE as possible for the bodyfeed, allowing those bars to rise a little for short runs, etc.
I seem to remember the iron content has something to do with the degree of calcination. Maybe someone out there can jog my memory on this one.....

In search of the perfect pint,

01-24-2005, 12:35 AM
Having filtered for many years using both DE and Perlite I know that if I was in a situation where I was having to chose between the two products I would opt for Perlite hands down. The brewery I worked in for the last five years used Perlite, on occaision we would run a test filter using DE, (Celite Product), these beers had a notable "earthy character", picked out by all tasters and Perlite filtered product was prefered.

I also have experience with PVPP usage what were your specific questions.