Diatomaceous Earth Filtering

[Brettman]

Hi all,

I have been doing allgrain brewing for a year or so now, and am pretty happy with how things are going. I bought a keg and filtering system that uses a 1 micron absolute cartridge. The filtering in my opinion really improves the taste and obviously the clarity and appearance of the beer, but some haze remains even when using polyclar. I have read small snipets on here about using diatomaceous earth as an additive to the cartridge filter to further improve the clarity. The only place I have found diatomaceous earth in small quantities is the local pool supplier. The first person that I spoke to suggested that diatomaceous earth was toxic and should not be used in the process of filtering beer, (which I don't agree with by the way, as the comercial breweries use it). The second pool shop owner that I spoke to seemed to think it would be ok, but advised me to be careful in the handling of it, as if it is breathed into the lungs, it tends to accumulate, and over a period of time, can cause cancer. That does not worry me too much, I think it is just a matter of being careful in the handling process.

Does anyone else know of any health risks of DE or have any suggestions as to how to use it effectively?

Cheers,

Brett

 

[fraser_john]

I do believe that some forms of DE are considered a cancer causing material, requiring the use of respirators during use!

 

[DUANNE]

i dunno about using de , but i personally would be looking for a solution back in the brewing process first. how long do you cold condition before filtering?
what other finings are you using and how? even right back to mash ph and calcium content. this is more were id be looking first to narrow down the problem before using de in your filter, butthatcould be just me.

 

[Brettman]

i dunno about using de , but i personally would be looking for a solution back in the brewing process first. how long do you cold condition before filtering?
what other finings are you using and how? even right back to mash ph and calcium content. this is more were id be looking first to narrow down the problem before using de in your filter, butthatcould be just me.

Usually I add whirlflock about 10 minutes before flameout, and no chill. After the beer finishes fermenting, I turn the temp down to 1C and leave for a day. I then add polyclar and leave for another day, and filter. I didn't realize that cold conditioning had an effect on beer clarity after filtering, perhaps that is the problem I have. I haven't looked into PH and calcium content either.

I am wondering if also I have un-realistic expectations. Is it reasonable to expect to get a beer as bright and clear as a commercial beer?

Thanks for the feeback.

 

[smilinggilroy]

Hi Brett,
Many years ago when I used to keep tropical freshwater fish I used a DE filter when cleaning the tanks.
After about an hour a 6 foot tank was crystal clear. Never lost a fish, so with you being told its toxic I would say not.
Try an aquarium, aquarium supply place for the DE or DE set up.
I would advise to do some more thorough research with it being a consumable beverage (not fish water) but who knows
DE filter set up only might be an interesting prospect.
Cheers.

 

[smileymark]

When I worked in a winery the used DE for filtering the wine. I cannot imagine it being cancer causing..To my knowledge they still use it....

 

[ianh]

If you Google MSDS diatomaceous earth - the results will blind you with science.

Basically you need to avoid breathing in the dust (use a dust mask when handling).

As others have suggested I would look at other things in the brew cycle to try and improve the clarity of the beer.

 

[MHB]

DE is a hazardous dust and can cause silicosis; it's also a PITA to use properly.
Under no circumstances should you breathe the dust.

To use it you need a good strong support media (often paper on/or a ceramic, plastic or metal filter surface), onto this you build a layer of coarse DE powder by slurring the DE and then recirculating through the filter. Onto the support layer you build a second layer of fine DE by the same process, this is the filter.
As the beer is being filtered its quite common to "Body Feed" still more fine DE by mixing it into the flow of beer, this continuously refreshes the filter surface.
You also need a hell of a good pump (no not a march pump) that has enough pressure to force the beer through the layers of DE.
These days it's becoming reasonably common to include an admixture of PVPP and Silica Xerogel (i.e. Polyclar or Polyclar Plus 730) and even filter-aids like paper pulp.
DE is falling out of favour except in very large breweries, apart from the dust hazard in the workplace the other main contributor is the cost of waste disposal. Another reason for the decline of DE filtration is new high end filtration technology that can and is replacing filtration/pasteurisation as a way to get beer sterile for packaging.

Most small breweries use "Paper" filters in a "Plate and Frame" filter press, the papers are impregnated with DE, these work well until they block up, then they are replaced. Brewers will try to get the beer as clear as possible before filtering, it's very important to get rid of as much yeast and proteinaceou matter as possible before filtering (mainly protein and polyphenols that precipitate during lagering) or you will be spending a small fortune on filter plates.

This really is a process outside the technical ability of most home brewers; probably why I call what is discussed as filtering around here "Sieving". If enough yeast is getting through that you can bottle condition on the other side the beer hasn't been filtered bright, you have just taken out the chunky bits.

MHB

 

[Hargie]

...this is me filtering our lager at work...it is quite a complicated and challenging job as this is a very good place to wreck a beer and really rather dumb to try at home...if you can't (or won't) cover up like this don't use it...

cheers
Scott

 

[Bribie G]

I think your post about cold crashing for one day speaks volumes. After racking into a cube with gelatine, I cold crash ales for a week at 2 and lagers for about 10 days, adding Polyclar two days before packaging. I don't filter.

Left: Gelatine plus polyclar.
Right: Gelatine Only

 

[white.grant]

View attachment 43069

...this is me filtering our lager at work...it is quite a complicated and challenging job as this is a very good place to wreck a beer and really rather dumb to try at home...if you can't (or won't) cover up like this don't use it...

cheers
Scott

OT

Yikes! As a lad we had a big sack of DE in the shed, used to dump it into the pool filter by the hand -- really helped clarify the water. It was so amazingly soft and fine, I used to love just running my fingers through it :blink: .

I wonder what it has done to my lungs, but then between that, growing up in Newcastle, using fibro sheet for chalk and smoking for 25 years, it probably isn't going to make all that much difference...


grant

 

[Thirsty Boy]

A 1 micron absolute plus something to deal with chill haze (eg polyclar) should get your beer pretty damn bright, but it wont be as bright as a commercial beer, nearly, but not quite.

However, there should not be noticable "haze" of any description, if there is, there is some chance you are getting either a little bypass of your filter, it has a small hole in it perhaps - or more likely, you just aren't using enough polyclar (or not giving the amount you use enough contact time) and you still have a little chill haze forming in your filtered beer.

If you want absolutely sparkly bright, just like commercial beer, the easiest way to get it will be to simply bang a tighter filter into the process - go through the 1.0 micron and into a 0.3 or 0.2 micron. That's about the same order of filtration you would get out of a DE filter anyway. But be warned, at that level of filtration, there is a high probability of you stripping out noticable amounts of colour, flavour, bitterness and aroma - especially hop flavour/aroma.

And it still wont help if the problem is that you aren't using enough PVPP. So first thig to do is see if the beer clears up when it warms up and make sure its not a chill haze issue - then check your filter surface for damage, give the seals etc a bit of a check for damage, and smear a good amount of food grade lube on the gasket faces when you seal up the filter next time. Also, if you filter from keg to keg - there is a possibility that your pressure differential between the two kegs is too high and you are "forcing" some cells/particles through the filter - and if its ever been really high, you may have done physical damage to the filter itself and caused it to be less effective. So, try dropping the differential pressure or even just filtering by gravity.

As for DE filtration - you could make it work without doubt, but not just by adding some DE into your normal filtration routine. You would ned to set yourself up with a proper DE filtration rig, and then it would be possible - but it also wouldn,t really be all that much more effective than you can achieve with just plain old cartridge filters.

TB

 

[wynnum1]

Zelbrite has any one used it

 

[Brettman]

A 1 micron absolute plus something to deal with chill haze (eg polyclar) should get your beer pretty damn bright, but it wont be as bright as a commercial beer, nearly, but not quite.

However, there should not be noticable "haze" of any description, if there is, there is some chance you are getting either a little bypass of your filter, it has a small hole in it perhaps - or more likely, you just aren't using enough polyclar (or not giving the amount you use enough contact time) and you still have a little chill haze forming in your filtered beer.

If you want absolutely sparkly bright, just like commercial beer, the easiest way to get it will be to simply bang a tighter filter into the process - go through the 1.0 micron and into a 0.3 or 0.2 micron. That's about the same order of filtration you would get out of a DE filter anyway. But be warned, at that level of filtration, there is a high probability of you stripping out noticable amounts of colour, flavour, bitterness and aroma - especially hop flavour/aroma.

And it still wont help if the problem is that you aren't using enough PVPP. So first thig to do is see if the beer clears up when it warms up and make sure its not a chill haze issue - then check your filter surface for damage, give the seals etc a bit of a check for damage, and smear a good amount of food grade lube on the gasket faces when you seal up the filter next time. Also, if you filter from keg to keg - there is a possibility that your pressure differential between the two kegs is too high and you are "forcing" some cells/particles through the filter - and if its ever been really high, you may have done physical damage to the filter itself and caused it to be less effective. So, try dropping the differential pressure or even just filtering by gravity.

As for DE filtration - you could make it work without doubt, but not just by adding some DE into your normal filtration routine. You would ned to set yourself up with a proper DE filtration rig, and then it would be possible - but it also wouldn,t really be all that much more effective than you can achieve with just plain old cartridge filters.

TB

A couple of interesting points there. My beer currently is no where near as bright as a commercial beer, so I need to get this sorted. I did actually try a finer filter a while ago. All I could find where 0.35 nominal, and 0.5 nominal, which apparently are probably no better than 1 micron absolute. I then found a 0.2 micron carbon filter. I tried that, but beer in one end, got water out the other! Very effective filtering! I am hoping to find somewhere something like a 0.5 micron absolute filter. That might be a happy medium.

As far as filter pressure goes, I have always gravity filtered anyway. When I first noticed the problem, I tried lowering the fermenter down to almost the same height as the keg that I am filtering into. This certainly lowered the pressure down.

From reading all the feedback I am getting, I am starting to think that I need to rack into a cube and let it sit for a week or so. I have always used polyclar by the directions.

Thanks for the help chaps.

 

[Thirsty Boy]

A couple of interesting points there. My beer currently is no where near as bright as a commercial beer, so I need to get this sorted. I did actually try a finer filter a while ago. All I could find where 0.35 nominal, and 0.5 nominal, which apparently are probably no better than 1 micron absolute. I then found a 0.2 micron carbon filter. I tried that, but beer in one end, got water out the other! Very effective filtering! I am hoping to find somewhere something like a 0.5 micron absolute filter. That might be a happy medium.

As far as filter pressure goes, I have always gravity filtered anyway. When I first noticed the problem, I tried lowering the fermenter down to almost the same height as the keg that I am filtering into. This certainly lowered the pressure down.

From reading all the feedback I am getting, I am starting to think that I need to rack into a cube and let it sit for a week or so. I have always used polyclar by the directions.

Thanks for the help chaps.

Try the heating up trick to see if its your polyclar dose and you are just suffering from particularly stubborn chill haze - the instructions for polyclar are only any good if they work. Maybe they aren't working for you. Apart from that - if your 1 micron abs filter isn't giving you results that are pretty close to commercial brightness, then there is something wrong with it. Its not that the filter isn't fine enough - it just isn't working properly.

There should just not be any haze after a 1 micron filtration. The difference between it and commercially filtered beer should be in subtle differences in how it picks up the light, how it sparkles. The difference you'd see between a gem made of cut glass and a real diamond. They are both "clear" but one is somehow "brighter".

 

[RdeVjun]

My beer currently is no where near as bright as a commercial beer, so I need to get this sorted.

Are you sure of that? How does your beer compare to commercial beer* for flavour though? If its better, then I wouldn't worry about filtering quite so much.

Just putting that out there... :icon_cheers:

* Disclaimer: That's a very wide spectrum I'll admit, I'm thinking along the lines of megaswill.