Port Fining and stabilizing

[Paul_B]

Ok folks,

can someone describe the deal here with egg whites, gelatin, milk etc... what is the most common agent used for Port?
I'm proud of my port knowledge limited as it is, but i have to admit that this topic as it applies specifically to Port still escapes me. So if anyone here can shed some light it would be great.

Thanks
Paul

[Frederick Blais]

I don't think I have the knowledge to generalize on this, so I'll just write about the producers I have visited and their techniques.

For the tawnies and white port, they mostly do cold stabilisation. Which means they lower the temperature of the liquid to precipitate most of the components that could prind cloudy, dregs or deposit in a bottle of port on the shelves.

For rubies style, they are mostly avoiding the deposit in the bottom of the tanks/pipes/barrels and using a selective membrane for what they want to keep or not.

For most ports, a racking occurs, which is topping barrles with other barrels. During that process, they try to not put deposit into other barrels, so some gets eliminated there.

For VP, not much filtration occurs, if none.

[Roy Hersh]

It is my understanding that there is NO filtration of VP prior to bottling.

[Andy Velebil]

I don't think you can generalize this as there are many ways in which to do it. Cold stabilization, a commercial fining agent, etc. But other than a basic medium fine metal, VP isn't fined or cold stabalized.

[Carlos Rodriguez]

Paul,

As far as I know, they use it "to clarify" the wine. That is to clean the particles in suspension that wine have after fermentation. It consist of adding to the wine a clarifying product capable of coagulating with the solid elements that turbit it and of producing grumes that, for sedimentation, drag to the bottom of the deposit. Generally, they use clarifying multifaceted (protein), like egg whites, gelatin, etc.