The Colour of Wine
How wine gets its wide array of colours.
For the most part, everyone seems to have a favourite colour when it comes to wine, if not also a favourite grape and style. I’m a textural white or orange wine person myself, although I dip my toe in the red and rose camp pretty regularly as well. However, I’ve been finding that the origin of colour in wine is a matter of confusion for some people. They might know what do or don’t like in terms of colour but not how it came to be that way. Here’s a quick overview of how wine gets its colour so that you can wrap your head around it a little better.
White wine is usually made from white grapes, although they’re actually more yellow in colour than white. The colour of white grape skins ranges from greenish-yellow to a more golden, sometimes almost orange, colour. The flesh is white or translucent. Because the juice of white wine is pressed off from its skin fairly quickly – usually within a day or two of being picked – the juice doesn’t pick up a lot of the flavour or colour compounds from the skin. As such, the juice stays quite pale and clear in colour.
White wines don’t necessarily have to be made from white grapes though. They can also be made from red grapes that are pressed directly after picking, so the colour compounds in the skins of the grapes don’t have a chance to steep into the juice. Take Champagne as an example. While there are some (delicious) rose Champagne’s out there, most Champagne is made from what we would consider a white wine as a base. Yet many of the Champagne’s most commonly drunk contain some portion of Pinot Noir and/or Pinot Meunier, both red grapes. The three grapes are traditionally blended for the flavour characters that they lend to each other. The actual amount of each in the blend is determined by the winemaker according to the style that he or she wishes to make - dry and bracing or fruity and supple are both possible in sparkling, plus everything in between. Yet you would never suspect, looking at it in the glass, that your white Champagne is made from red grapes as well as white.
Orange or Amber wine
This is white wine made with the skins left in contact with the juice (called maceration) for an extended period of time. For example, I make most of my white wines with a bit of skin contact, generally two weeks or longer. The Georgian tradition is to make them with six months of maceration. During that time, they draw out a lot of flavour compounds in the wine, called phenols. Some phenols are antioxidants, meaning that they react with oxygen. When they do this, they change colour, becoming more orange, similarly to how iron oxidizes to a rust colour in the presence of both oxygen and water. Even if a wine isn’t oxidised per se, small amounts of oxygen will have this effect and create a more orange hue in white wines rich in phenols. In essence, this is white wine made in the same way as red wine.
Rose sits somewhere in between a white wine and a red/orange wine, as far as how it’s made. Rose can be made from any red grape that’s had a short amount of skin contact, anything from a couple of hours through to a couple of days. The juice of most red grapes is clear if pressed straight after picking but if left with the skins, the juice will extract phenols and colour compounds found in the skins. If left for a couple of hours or longer the wine will have a bit of a blush. The longer the maceration, the greater the extraction of colour and flavour compounds, and the deeper the colour. Once the maceration goes over a couple of days though, the colour will intensify to the point where we would start to consider it a red wine.
There are a couple of exceptions to this though. Some grapes that are traditionally known as “white” grapes are actually a grey-ish pink colour, so extended maceration on skins produces a pink colour. While these wines would fit in more with our understanding of how orange wine is made, at first glance they look like a rose. One example of this is Pinot Gris, also known as Pinot Grigio.
Red wine is made from red grapes with extended skin maceration. The skins are left with the juice for long enough for the colour to deepen to red. In this case, there are enough phenols extracted from the skins that they also play a predominant role in the wine’s flavour profile, creating wines that are more savoury and structure than rose or white. The hue and depth of colour varies according to the grape but this is the basic principle by which red wine is made. There are also a few rare grapes that have red flesh, known as teinturier grapes, which can produce a red wine with barely any skin contact at all. Last year I made a wine from Saperavi, a Georgian grape with red skin and flesh, with only four hours of skin contact. This would barely be long enough to bring a blush of pink to many other wines, but four hours of skin contact saw my Saperavi end up a colour reminiscent of a Gamay or Pinot Noir.
So there you have it – the basics of wine colour. There’s plenty more nuance to it – the depth and tone of colour can be manipulated in each every wine through growing, picking, winemaking, and ageing decisions - but these basic principles should give you enough insight to look into your glass and understand how the colour came to be in there.