View Full Version : DE Filtration leaving taste

08-04-2005, 10:34 AM
Just wondering if any of you had any case of DE filtration leaving a taste in finished product. I've been using this system for quite a while now and I always find there's a weird taste (earthy taste) in the beer, compared to our wheat beers (no filtration) where everything's fine. Any ideas? I'm considering switching to a Perlite system, will it change something? I don't know a single thing about Perlite...

Thanks for your help!

08-04-2005, 10:49 AM
The easiest way to see if DE leaves a taste in your beer is to pour some in a glass and add distilled or RO water to it. Let it sit for 1/2 hour and then smell and taste the water on top. That will give you everything you need to know. If it tastes and smells like a nail, well that's iron. DE will pick up odors rapidly just by being stored next to something that smells-onions, moldy walls, chlorine cleaners, etc. Any taints will show up with this method also.

The most common flavor contribution from DE is Beer Soluable Iron (BSI). You can get the level of BSI from the manufacturer if you can find the lot number on the DE bag. Ideally it is below 10 ppm. You can request low BSI DE but only certain grades will fit that category. You can send your DE out for an analysis also.

Low iron DE mines are rapidly shrinking, and most of the large breweries have already contracted the supplies for as long as they can get it.

Good luck with Perlite filtration. It is possible to make clear beer with, but it is not as good as DE.

Larry Horwitz
08-05-2005, 04:17 AM
Celite z grades are partially de-mineralized (lower BSI) we currently use 512Z with great success. If you want a cool trick to getting down the 'earthy' flavor, try this: Precoat with water, and mix in a tiny bit of citric acid. The acid will lower the pH and leech out a lot of the mineral from your DE, est Beer Soluable Iron. Since the precoat is a big part of your total DE load you will see big changes in finised beer flavor. Don't use perlite....just don't do it. And if you do, remember it is just as big an inhalation hazard as DE. Also, it has lower mass than DE.....so don't just sub it in pound for pound.

all filtration alters beer in some way....

08-08-2005, 11:26 AM
Thanks for the tips, I'll investigate my DE source ... :cool:

08-12-2005, 08:17 AM
Why anti-Perlite?I switched from DE to Perlite a while ago, and after some initial hassle due to the Supplier sending me the wrong grade i have not had any problems. My filters are faster with less pressure rise and cleanup is easier. I dont use near as much by weight either. One thing I noticed was that when filtering a beer with signifigant proportions of wheat in the grist (25% or more) you will get haze. Other than that no problems. If you are a brewpub brewer serving on premise I would think Perlite is superior. Maybe a production brewery who needs or wants the tightest filter possible would use DE but I wont touch it again. I actually talked to a brewer who doesn't like Perlite because he misses that subtle "DE" flavor.

08-16-2005, 11:39 AM
So what are the big differences in-between using DE or Perlite? Did anybody switched from one to the other, and why you did this?

08-16-2005, 02:55 PM
DE provides a much tighter filtration than Perlite does. The answer is in their microscopic structure. DE is the silicon shell of a Diatom, and Perlite is a volcanic byproduct (expanded rock-"rice crispy-like"-puffed appearance). DE has more surface area to impound particulates in the filtration bed than Perlite does. Perlite can produce a clear liquid. It is safer to use. It is lighter than DE. It doesnt contain Iron.

I've done some experiments with Perlite as the precoat and DE as the body feed. Results: it worked, but slightly hazier than DE alone. Needs more work.

Perlite Under Microscope attached. Note the "flakes"
DE Under Microscope attached. Note the hollow spheroids with porous surfaces.

08-17-2005, 07:37 AM
While I admit DE is a tighter filter aid, Perlite can and will produce beer with no haze provided that your hot and cold side processes are up to par. I filter with only Grade 7 Perlite (no DE, no Cellulose etc.) 7 for pre-coat and 7 for dosing. Clear beers no haze. Like I mentioned previously If you have a beer with a signifigant portion of wheat then haze is an issue. It is pretty simple to order a bag of Perlite and try it for yourself. There are finer grades than 7 as well you just have to look around. Just try it, the worst that will happen is that you will have to re-filter a batch if you get haze. When I initially used Perlite my supplier sent me grade 3 which is not tight enough and I had immediate haze, I was able to add standard DE to the doser and clear the beer up. One thing you could also do is pre-coat with DE and dose with Perlite, I know Brewers who have good success with this method as you get the best of both worlds. Nothing beats firsthand experience. Every brewer has his own unique way of filtering and as it is the touchiest of all the processes they are reluctant to change, if it aint broke dont fixit. Cant argue with that.

08-30-2005, 07:41 PM
I have heard from several DE suppliers, BSI decreases with time. Supposedly AB buys DE and stores it in where houses until the BSI is below their acceptable limit.
I know Eagle Pitcher has a higher BSI than (brain fart cant think of the name), the company that produces Speed Flow and Speed Plus.
Therefore if you have the $$ buy a skid and eventually the older bags will have a very low BSI. What is the half life of BSI, I donít know. But it does oxidize (I believe is the word) over time.

08-30-2005, 08:06 PM
I tried mixing some of my DE with distilled water and tasted it... I think that just solved the problem... Thanks for the tips guys, for now I'm switching to Perlite. I'll go back to DE after I upgrade to a 20BBrl brewery... :D


Larry Horwitz
08-31-2005, 06:12 AM
Anheiser Busch buys and uses celite 512Z which is the partially demineralized 0.5 darcey perm diatomite. They wouldn't waste time storing it even if they wanted it aged...they'd have the supplier do it.