Can filtration strip hop aroma?

[Woolsocks]

I was filtering our IPA with "3 micron" perlite on my pressure leaf (aka DE) filter and could have sworn I could smell hops more in the unfiltered product. Last I checked, hop aromatics were to small to be filtered away -- am I wrong?

P.S. I usually mix some PVPP into the precoat -- could that be a factor?

[South County]

I would say yes, particularly in the event that the aromatic hops were late late additions and/or dry hoped. These oils are more in suspension rather than isomerized/bonded in the beer. Why so small? (3 micron).

Exerpt from technical article:


Bright beers, such as pale ale, then go through a very slow, very coarse, plate frame containing diatomaceous filter of about 4 microns. This enhances the final clarity of the beer.
"By doing it very slowly, we get almost no oxygen pick up," Harrison says. "What the big breweries, and many of the beers that are non-pasteurized, do is they go through a sterile filtration at about half a micron. While you actually filter out bacteria, you also strip aroma, flavor and viscosity.

So maybe larger micron filter media and a slower filtration rate may give you the same results but leave the desired attributes you intended.

[Woolsocks]

Why so small? (3 micron).

Well, that's just the "nominal" pore size -- no absolutes with depth filtration anyway. Basically I've had good luck with that particular product. Still, I think I'll try some coarser stuff next time.

[wiredgourmet]

Your observation makes sense to me. At 3µm, hop aromatics won't get filtered per se, but the filter medium itself will absorb some. Also, hop oils and acids cling to yeast, so when you remove them, you are removing a carrier of some aroma and bitterness, if not pulling the aroma directly from the beer itself.

But how does the beer smell and taste? If it's good, I wouldn't worry. Otherwise, you probably only need minor adjustments to your hop regimen or filtering procedure, or both.

[Beersmith]

Woolsocks, IMO filtering (with anything) always changes the flavor/aroma profile of a beer to some degree. All you have to do is taste an unfiltered bright beer then filter the same beer and taste again. That being said you can plan ahead and introduce more hop flavor/aroma in your beer knowing that you will strip some out. Of course, you can always sell your filter and come over to the "not quite as bright side".

[Woolsocks]

Of course, you can always sell your filter and come over to the "not quite as bright side".

I'm actually thinking that way for this particular beer. A little isinglass in the bright beer tank, a little haze in the beer, and more vitamins for the customers. Not gonna sell it, though: hate to have a murky pilsner.

[william.heinric]

There are a couple of ways of adding aroma and flavor pack into the filtered product as well. Putting a hop-back between your filter and BBT would up the hop ante, or you could try directly injecting hop oils (not the alpha acid paste, but the non-alpha flavor oils) into your beer line with a cornie keg. I've done the later, and am moderately pleased with the results.

The oils work better when they have a chance to sit for a couple of days.

Bill

[wildcrafter]

I find this filtering issue interesting. I asked a couple of chemist buddies about this too.

Question1-- the aromas stuck to the yeast that gets filtered out.
What do they stick to? Proteins? Phospholipids? Adhesion of the aromas to the exterior of the cell wall or are they in the cell?

Question2-- DE itself.
Isn't it like a zeolite? If so, it might filter out small molecules. Interestingly, activated charcoal seems to filter out large molecules only---a zeolite opposite?

Any thoughts?

I'm seeing a relationship I can work with here.;)

[porter]

We used to filter all of our beers with a plate and frame and I have since started using Biofine from Brewers Supply Group.
It has made such a huge difference in the hop aroma retention for our Pale Ale and IPA. The beer ends up extremely bright and even my Golden Ale (Kolsch style) looks as though it's been filtered.
I use 1 liter in 14 bbl (about $10), force carb in the afternoon, and by the next evening it's all cleared up and ready to go.

[Woolsocks]

I've had tremendous luck using biofine in our casks, after having ordinary gelatin and isinglass barely affect them at all. I've been considering using it on a whole batch of beer but have been afraid of it not working and having to filter anyway.

Is there any good info (I've looked) about what the ingredients of biofine are besides isinglass? Kerry doesn't seem too forthcoming about the details of their products.

[BigMuddyBrewing]

We used to filter all of our beers with a plate and frame and I have since started using Biofine from Brewers Supply Group.
It has made such a huge difference in the hop aroma retention for our Pale Ale and IPA. The beer ends up extremely bright and even my Golden Ale (Kolsch style) looks as though it's been filtered.
I use 1 liter in 14 bbl (about $10), force carb in the afternoon, and by the next evening it's all cleared up and ready to go.

Which one are you using?

Biofine P19 or Biofine Clear A3?

Thanks,

Chuck:confused:

[porter]

I'm using BioFine A3 from Kerry Bio Science. I've attached (or attempted to) the spec sheet and msds from BSG. Not alot of info, but hope it helps. I haven't been using it that long, but I'm happy to share my experiences.
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