Winegrapes

If you are not a researcher or your research background is not in winegrape ecology, knowing some basic wine grape terminology can be a good place to start. This set of wine-specific vocabulary will give you a head start in understanding the research we do, and it may make the content of our Publications tab a bit more interesting.

One of the most important things we pay attention to is the phenology of winegrapes. You can observe the most important phenological stages of winegrapes below. 

    • Phenology — recurring life-history events, or–to put it more simply–biological seasonal events that repeat (e.g. date of maturity, bud-burst, flowering and veraison).
      • Budburst — during cold winter months, grapevines enter dormancy and develop brown scales to protect their buds from harsh weather. When temperatures rise again, the buds will swell, become fuzzy, and new leaf tissue will emerge. 
      • Flowering — the process of flowering begins with small compact flower clusters appearing on the tips of young shoots. A few weeks after the initial clusters appear, the flowers start to grow in size with individual flowers becoming observable. It is during this stage of flowering that the pollination and fertilization of the grapevine takes place with the resulting product being a grape berry.
      • Veraison — from the French word for ‘to turn’ this is the turning of the grape berries that signals the beginning of the ripening process (more specifically it’s when sugar in the grape starts to rapidly accumulate). For red grapes, the berries change color, for lighter grapes they become more translucent and for all grapes they begin to soften. 
      • Maturity — it’s complicated! It’s actually something we work on in the lab. Maturity is when the sugar, acid, phenolics, aromas and more are ‘just right’ in grape berries and thus ready to be harvested. Right now we work on ‘sugar maturity’ which varies depending on wine style (for example, for sparkling you need lower sugar levels), variety and preference.

Other vocabulary as applied to winegrapes:

    • Vitis vinifera subsp. vinifera — is the winegrape! It was domesticated from Vitis sylvestris (the only grape species in Europe)  in Europe 9,000 or more years ago. 
    • Variety (synonym with cultivar) — a variety is a particular winegrape which has been created through selective breeding (for winegrapes this is generally via plant crosses and most of the varieties we drink today were created centuries or millennia ago) for a suite of characteristics (heat tolerance, berry size, flavor, phenology). Examples are Pinot noir or Cabernet-Sauvignon. 
    • Clone — within each variety there are generally multiple clones. Clones have small differences (much smaller than the differences between varieties) that have generally appeared spontaneously in the DNA.  This variation adds another level of crop diversity and is studied in-depth by Eric Duchene’s lab . Note that winegrapes are a clonal crop—they are grafted and thus effectively identical around the world. 
    • Ampelography — is the study of winegrape diversity with an emphasis on being able to identify different winegrape varieties based on their characteristics (in North America this is leaf shape, cluster and berry traits, in Europe it also includes the flavor of the wine). Our work relies heavily on help from ampelographers — Thierry Lacombe (France) and Andy Walker (USA). 
    • Root stock — the bottom portion of a winegrape plant, it is generally a North American Vitis species or a cross of Vitis species (e.g. riparia).
    • Scion — the top part of a winegrape plant, it is often 100% Vitis vinifera subsp. vinifera 
    • Hybrid — A cross between Vitis vinifera subsp. vinifera and another Vitis species (usually North American) that brings beneficial traits such as disease resistance or cold tolerance.

Some particulars …

    • “Winegrape” is one word (though sometimes journals and the press get confused on this).
    • Varietal is what’s in the bottle, variety is the plant. 
    • Variety names should be capitalized, even if the Associated Press style book doesn’t respect that, please respect the cultures that named the varieties and follow their conventions if you can.

Want to learn more? Here are some of our favorite websites: