Dry-hopped beer and clarity

[dmbrew]

Does anyone know if there's a correlation between dry-hopped products and clarity problems in the package? I use a centrifuge for primary filtration into the BT, then a Handtmann MultiMicro system for a polish on the way to the bottle. After a couple months I notice some particulates percipitating in the bottle, but only on those products which were dry-hopped. Any suggestions? Much thanks!

[BrewerTL]

Are you dry hopping with whole hops or pellets?

[Rob Creighton]

Assuming (because of the time delay) that you have a calcium carbonate fallout (white flaky chunks), is it possible that the dry hopping is not the problem? Do you acidify the mash water or treat your brewing water?
I have very little experience with packaged dry-hopped product but I would be more inclined to look at water chemistry and brewing profiles before hopping regimen unless you were somehow transfering particulate to your final product (which would be obvious immediately).

[dmbrew]

Thank you all.
More info might help huh? Here ya' go. I am dry-hopping with pelletized hops. I have tried in the past to acidulate the mash water, but saw no change in the packaged result. I'm using a 1 micron nominal pad set for the Handtmann filter just prior to the filler, and all recommended proceedures are followed. Anyone who can offer any advice on this matter would be greatly appreciated. Thanks again!

[MikeJordan]

I believe there is a correlation between dry-hopped beers and clarity issues. I used to brew a dry-hopped IPA where I used pelletized hops. My filtration practice at the time was a rough DE filtration with an .8 micron polish filtration. I used some stabalization products on the rough filtration. I found that I had to dose up the xerogel and the PVPP an extra 10-15ppm for this beer to be haze-free three months out. I always contributed the problem to the polyphenols in the hops and their reaction with proteins to form protein-polyphenol complexes. I believe ISP still sells this stabilization combination as one product with varying ratios of 60/40, 70/30, etc. I personally liked having the products seperate as it gave me more freedom for a diverse beer lineup. Best of luck!

P.S.--Ever considered using hop oils instead?

[dick murton]

I tend to agree with Mike's scenario - it certainly makes sense re protein / polyphenol haze complexes. I think this is more likely than inorganic precipitates - certainly not likely to be calcium carbonate, calcium oxalate (derived from phoshates in the malt and calcium salts in teh mashing water) if anything, though I suspect this is not the case if you get decent shelf life without dry hopping.

Personally I prefer whole hops as I consider they add a more rounded aroma & flavour that hop oil. You could try dry hopping in cold tank prior to filtration, but you will probably need a much higher hop rate than post filtration hopping.

Cheers

[Rob Creighton]

As usual, Dick outlines the issue more clearly than I but, the long distance, lack of product in front of me issue has not stopped me from thinking that the way you described the problem initially does not sound like a protein haze description. If the precipitate is inorganic it should be relatively easy to check and the timing of the fallout sounded similar to an issue I experienced before. Why it would effect only dry hopped beer I cannot say but I'm just going on your original description of the problem. If it was a protein haze settling out over time, I would think you would get hints of it much sooner in the bottle.
And Dick is right, it is calcium oxylate, not carbonate (gotta stop sampling and typing). Cheers!

[dick murton]

Just another thought on using hop oil and centrifuges.

If you add hop oil before filtration, the filter powder tends to absorb (or is it adsorb ?) some of the oil. Whatever the strict technical action, it means that you are unlikely to be able to filter another beer which does not have a similar level of hop oil addition immediately benind the hop oil treated beer. You will need to wash off the filter and start again. This probably isn't a problem in a small brewery anyway, as I expect you are only doing one or two tanks at a time.

Re centrifuges. Many centrifuges break up the fine protein material which would normally be removed by a filter, and the fines pass straight through. This is particularly likely where the beer picks up more than couple of degrees C across the 'fuge. Perhaps this is where some of the material reacting with the hop vegetation is coming from.

Cheers

[dmbrew]

Thank you!

Thanks guys,
I hadn't even thought of the polyphenol / protein reaction that could be taking place. And, as you all know, a centrifuge will let things through, to a degree. I have considered experimenting with aroma hop oils in place of pellets, but my concern with that is my Handtmann Micro filter in line to the filler. I'm using 1 micron pads, and commonly run several different products in a packaging day. Should that really be a concern? Will a standard flush / backflush regimen be effective on the trace hop oils? I do use a silica gel prior to the "fuge," but do not have the ideal dosing equipment. Will a blend of xerogel / pvpp help me when my dosing proceedure is not part of a DE filter system? Or, is it a waste of valuable brew-dollars? Thank you all for the suggestions so far, PROSIT!

[Aaron Taubman]

Same Problem here

We have the same problem with our Pilsner beer. After about 90 days we get a flakey sort of haze combined with a chill haze.

I have tried just about everything. Double filtering with silica hydrogel/pvp is about the most effective solution. It really eliminated the haze. But I really can't be doing that all the time as it is very time consuming, and we try to 'handle' the beer as little as possible here. I recently switched to using Polyclar Brewbrite in the kettle, and that seems to keep the chill haze in control on all of my beers but not the pilsner.

What sort of air rates do you get in your bottled product? I have been told that high air rates combined with dry hopping inevitably leads to a 'hop haze'. We have an old filler here and really can not get our airs below .8ml . So i'm sort of resigned to things the way they are until we get a new filler.

Cheers
Aaron

[dmbrew]

Bottled airs

My bottled airs come out between 0.04-0.05 ml, so I think we're getting good results on that end...thank you Krones! I'm using "Whirlfloc" in the kettle, but have considered other kettle additions. I guess trying aroma hop oils is my best chance right now. Thank you all!

[Ian.McL]

I know this is a couple years late, but I thought I could share some information in case someone stumbles upon this again, as this topic was a focus of my graduate research.

I do believe that this would be caused by protein/polyphenol interactions. Basically, the origin of this phenomenon is rooted in the types of proteins and polyphenols that are present in the beer.

When the wort is boiled much of the proteins (barley hordeins) are denatured and therefore in an open and extended stucture which makes them accessible to the to the polyphenols in solution (from malt and hops) and these associate to form flocs of trub, which get bigger and bigger, and eventually precipitate out and are left in the whirlpool. These associations are primarily between the proline residues of the barley hordeins and the aromatic rings of the polyphenols. This is not a chemical reaction, but it might be analagous to the attraction velcro has to its other half: it holds pretty well, but can come apart with a tug (only to re-attach later).

After the boil, most of the haze-active polyphenols have been removed in the trub, but there is still some protein left in solution. When dry-hopping you are adding more haze active polyphenols to the system, which in-turn allows for the eventual formation of more haze and trub-like sediment (sorta like Le Chatelier's principal). This can take a while to happen in the package because it is kind of dependent on the oxidation of the beer in the package. Once these anti-oxidant polyphenols begin to scavenge the oxygen in the package, they begin to re-polymerize into large molecular-weight structures, and due to their increased size they can more easily bridge the gaps between the protein molecules and cause haze. Once they get to a certain size, they fall out of solution.

Therefore, I would imagine the problem would appear sooner and be more severe if you have high headspace air levels. Also, it might be worse if you are using hop pellets rather than whole hops because the higher surface area of the hop material in the pellets might allow for a more complete extraction of the poylphenols into solution. I also found that the more acidic the solution, the more complete the extraction of polyphenols. $0.02

[Moonlight]

Thank you, Ian, for that concise explanation! I would like to agree that switching to whole hops may solve your problem. I use whole hops for dry hopping and see improved clarity over the same beer without any dry hopping. The flavor is more delicious IMHO.

[dmbrew]

Thanks

Thanks to both of you, Ian, excellent info! Our bottled airs are quite low, but maybe can be reduced further? I must research. As far as whole hops, I do not have the capability to use them in my process as tank space is not available. Bummer huh? But thanks again, I'll let you know if I figure something out.

[letsbrewit]

7 years after the last post but im having the same issues in my final product. I dont dry hop but we use a lot of flavor and aroma additions to our blonde ale and we get similar aromas to dry hopping, i was thinking the same that maybe its due to proteins and pholyphenols, we also do a 0.5 micron filtration before the isobaric carbonation, but at the end in the beer bottle and after some weeks we can see some floaties like a film but not in the surface they are floculating to the bottom. We have taste the beers and we dont se any change in the aroma and flavor. We plan to use hop oil post fermentation, any advice?