hops and protien

[whitemarshbrew]

Does significant dry hopping add to potential chill haze?

[beerking1]

I don't think it is protein haze, but large amounts of dry hopping definitely will produce a "hop haze."

[Moonlight]

In the beer or the drinker?

I'm thinking perhaps hop tannins coupling with beer protein, but could be wrong.

[whitemarshbrew]

I was told yesterday that the haze is from poly phenols. Anyone out there that can second that? If so what is the best method of removing these? I do not have DE filtration, and would prefer not filtering at all.

[Buckley]

Polyphenols, tannoids and proteins all cause a haze.

[TL Services]

As above, chill-haze or age-haze are formed by proteins and polyphenols joining to form a complex so, for a visible haze to form , it is necessary for both these to be present in quantity.

However not all proteins are haze-active. The longer chains are stable, so don't tend to cause haze issues and they also contribute to head retention. Specifically it is proline that is haze-active.

Proteins can be removed by selecting an effective copper finings or using an appropriate auxiliary finings further along the process. Polyphenol removal is usually carried out using PVPP, but this is expensive unless being done on a large scale where it becomes viable to regenerate it after use using caustic (NaOH).

Even so, the latter results in a loss of PVPP that needs to be replenished and good post-regen. rinsing, etc.

Incidentally, haze formation is accelerated/catalysed by high levels of dissolved oxygen.

[liammckenna]

If you pad filter, you can get sheets impregnated with PVPP (which are also regeneratable (is that a word?) to a limited degree.

I second the suggestion of kettle finings as well to help.

Pax.

Liam

[kai]

There begs another question; if you have a thorough kettle fining regime and add a lot of hops downstream from the kettle, can you expect your beer to be chill haze stable?

[TL Services]

Kai - I wouldn't expect to see any chill-haze issues, providing the copper finings are doing their job in removing haze-active proteins.

I would also suspect that dry hopping, ie. into beer, would be unlikely to result in as high a level of polyphenol extraction as adding to hot wort.

[liammckenna]

Could this phenomenon also be related to hop oils in the cold beer?

Also, I know that there is little solubility of hop acids in cold beer, but I guess theoretically at least, the addition of a really big dry hop charge may alter pH slightly downwards and thus cause certain reactions (ie protein/polyphenol interaction, or certain protein/polypetide fractions in the beer coming out of solution due to hitting their isoelectric point.)

Does anyone have any solid data of pH effects from large quantity dry hopping scenarios?

Some conjecture...

Pax.

Liam