Green tints ?

I was recently asked why some white wines exhibit a greenish hue, but didn't have true answer, only some theories. My guess is that the wine is made with a number of unripe grapes that still have green pigmentation in the skins and pulp. I've seen grape bunches that are golden on one side and greenish on the other. I would guess the green pigmentation is chlorophyll, which I don't think is very stable relative to the pigments in black grapes. This green pigmentation adds hints of color to the wine, but it is not very stable and will break down over time, leaving the wine with a typical yellow or golden hue. The presence of unripened grapes also implies a high acid wine. Studies of red wines show the hue of pigmentation is related to the pH of the wine. So, perhaps the greenish hue is also a function of acidity. I've had a greenish hue in some white wines I've made over the years, but only early in the process, before cold stabilization, doses of SO2, filtration and bottling. I believe these treatments tend to reduce the green pigments. Does anyone else have better knowledge than my theories regarding this subject?

Howie, Hi....

Most popular theory has little to do with skin contact but more to do with the relationship between glycerine and acidity, the tints ranging from green to orange. Of equal interest is the issue of reflections cast by the wine when held in different relationship to light - those from pale pink, green and orange and occasionally even violet, those reflections indeed often related to skin contact.

For details beyond this a two year course at UCDavis is advised and my guess is that will not give a full answer at any rate.

Best
Rogov

I have been wondering about this for a long time? I too considered unripe grapes but am not a wine-maker so willing to be educated. Daniel`s light theory should be considered too I guess. I have never come across a green tinted wine from S France (so far).

Some great Rieslings have a greenish glint, I'm not sure it's a sign of immature grapes.

I don't think the details of how wines look in the glass is discussed enough. Some wines just seem to reflect more light, for example; is this dry extract? I don't know.

i remember reading that this green tint is particularly evident in young chablis - and i have in fact noticed that. it was supposed to be related to high acid/low ph - which would explain there being none from southern france, but some from chablis and germany.

If it is related to acidity, wouldn't it be easy to test by adding acid or something that would remove acidity to white wine and observing the effect? Drops of red wine falling on paper often turn blue due to the alkalinity of the paper.

Oliver wrote......."I don't think the details of how wines look in the glass is discussed enough. Some wines just seem to reflect more light, for example; is this dry extract? I don't know."

That is a very interesting point sir! A white-walled/tiled room with sufficient lighting might be the answer!! Seriously though, lighting can play a part in our color remarks. I normally go from straw thro`to yellow and onto gold. It`s the in-betweens that stump me sometimes.

Just crushed a little under a ton of grapes today, the pulp of the grapes themselves is generally a pale green to yellow color.

Salute

Oliver wrote......."I don't think the details of how wines look in the glass is discussed enough. Some wines just seem to reflect more light, for example; is this dry extract? I don't know."

That is a very interesting point sir! A white-walled/tiled room with sufficient lighting might be the answer!! Seriously though, lighting can play a part in our color remarks. I normally go from straw thro`to yellow and onto gold. It`s the in-betweens that stump me sometimes.

Bob,

You're quite right, we don't taste very often under ideal visual conditions. But some wines just seem more brilliant than others, and I've never known why. I imagine it's measurable...

Oliver wrote......."I don't think the details of how wines look in the glass is discussed enough. Some wines just seem to reflect more light, for example; is this dry extract? I don't know."

That is a very interesting point sir! A white-walled/tiled room with sufficient lighting might be the answer!! Seriously though, lighting can play a part in our color remarks. I normally go from straw thro`to yellow and onto gold. It`s the in-betweens that stump me sometimes.

Embalming room.

At a first-timers wine tasting this past Saturday evening, we had two chards. One, from Calif., was un-oaked, unfiltered and had not undergone MLF - it was a clear, sparkling straw color. The other from Australia was well oaked, and had undergone MLF and it had a light green hue. There are too many variables to know what might have caused to greenish color but we spent some talking about it. I'll share this post with the group next time we meet.

Yellow and blue makes green.

Salute