The science of color

[g-man]

Question for my fellow port drinkers.

It got me thinking, why some vintages retain their color much better then others.

The F-85 is dark as night, the F80 not so much.

Neither is the fantastic f-77 actually, but the older F-70 almost rivals the F-85 in color.

While I understand some vintages are stronger then others, I would imagine that translate to the taste balance and not necessarily the color.

So, what would be the characteristics that define how long a port will retain its colors before bricking? Wine making technique? Storage environment? Mother nature? Bottle shape? Bottle color (green vs, black)?

[DRT]

I don't pretend to understand the chemistry but I associate good colour retention with wines that are slow to mature. Port needs good levels of acidity and tannin in order to age gracefully over many decades and it seems that the retention of colour is a bi-product of that process in that the dark solid matter that forms the crust does not precipitate out as quickly as it would in a lesser wine.

I'm sure one of our budding chemists will now chime in and tell me I'm talking nonsense