Technical Wine Terms G to L

  • Gravity flow: refers to a style of winemaking where gravity is used to move fruit, juice and wine around the winery. It is essentially a modern revival of an ancient practice, and moves the grapes more delicately, and with less chance of oxidization. Gravity flow (or gravity fed) wineries have multiple levels, and are often located on hillsides. In single-level wineries, conveyor belts, forklifts and other equipment can help achieve gravity flow transfers.

  • Greywacke: a variety of hard, often dark- colored sedimentary sandstone made up of a mix of mineral and rocky fragments, including quartz, feldspar and compact clay. A subsoil rich in greywacke is thought to impart mineral characters to a wine.

  • Grosslage: a German geographical classification denoting a cluster of einzellagen (individual vineyard sites). Not to be confused with Grosse Lage (see below)

  • Grosse Lage: Germany's top-rung classification for an individual vineyard site, equivalent to France's Grand Cru. Not to be confused with grosslage. See German Wine Label Information.

  • Growing season: the period in a year after grapevines emerge from their winter dormancy and go through a growth cycle, from the first buds of spring continuing through to summer and autumn when the grapes are ready to be harvested. In the northern hemisphere, the normal growing season is between March and October, while in the south it runs from September till April.

  • Hang time: the time between flowering and harvest when grapes are left on the vine to achieve physiological ripeness.

  • Ice wine: derived from the German word 'Eiswein', it refers to the sweet wines produced from grapes which have been frozen while still on the vine. These frozen grapes are then pressed, resulting in the heavier, sugary liquid separating from the lighter frozen water which floats on top. This liquid is so concentrated that a high level of residual sugar is left after the alcoholic fermentation is over, producing a lusciously sweet wine. Germany, Austria and Canada are the world's leading producers of icewine.

  • INAO: Institut National de l'Origine et de la Qualité, formerly Institut National des Appellations d'Origine, the French government body responsible for the creation, maintenance and enforcement of French appellation laws since its inception in 1935. It controls nearly 500 wine appellations and many thousands of variant forms, as well as an increasing number pertaining to food, such as cheese, poultry, fruit, olive oil and mustard.

  • Lake Effect: refers to the temperature-moderating effect of large bodies of water, most famously the Great Lakes of North America (see Michigan). Water's high thermal storage capacity means that it heats up and cools down more slowly than land and air. On summer afternoons, warm air rises off the land, sucking cool lake air into its place and creating cooling onshore breezes. In fall, the reverse happens; the summer-warmed lake creates a warming effect on the surrounding land, delaying the first winter frosts and extending the growing season.

    The term is also widely associated with 'Lake Effect snow'; heavy, sudden winter snowfalls caused by the reaction of cold air with warm, moist air above the lake. Lake Effect snow acts as a natural insulating layer over vines, allowing them to survive even when air temperatures drop well below freezing.

  • Late harvest: wines produced from grapes that are left on the vine for longer than usual, in order to achieve a higher sugar level. Most late-harvest wines fall into the dessert/sweet wine categories. Late-harvested grapes are also likely to be affected by noble rot in moist conditions (such as Sauternes and Tokaji). In northerly latitudes they are also susceptible to freezing - ideal for the production of icewines.

  • Latitude: a location's distance north or south of the equator. This has a profound effect on a region's overall climate, and therefore its suitability for growing grapes. Broadly speaking, the most suitable latitudes for viticulture (the 'wine latitudes') are between 30°N and 51°N in the northern hemisphere and 28°S and 46°S degrees in the southern hemisphere.

  • Lees: a generic term for the solid particles settled at the bottom of a tank/barrel after alcoholic fermentation. It consists of dead yeast cells, pulp, seeds, skin fragments and any other insoluble particles. Lees is an important factor in determining the quality and style of many wines, such as the famous Muscadet sur Lie from the Loire Valley in France and New World Chardonnays which are matured with lees contact. Apart from adding to the flavor, lees contact also imparts added mouthfeel to the wine.

  • Lieu-dit: a French term, literally meaning 'place-called'; in wine making, a named vineyard. Traditionally, lieux-dits lie within a larger appellation but do not have their own legal designations. It is common to find these vineyard sites mentioned on wine labels from Burgundy and Alsace where they have consistently produced high quality wines - mostly attributed to a superior terroir. Although technically these sites cannot claim an official status, many of them have gained a reputation equal to the more well-known appellations, if not higher.

  • Lightly oaked: an imprecise term usually employed in descriptors of the finished product, rather than as description of the winemaking. Perhaps most often applied in marketing to Chardonnay wines, which some consumers expect to always be heavily oaked. A producer might only use oak in fermenting or ageing a portion of the wine, using stainless steel or cement tanks for the rest. The wine might be part-fermented and/or aged in oak for a short time before transfer to tank. The use of neutral old barrels may produce an even subtler effect for which the term is a less suitable fit. For more detail see The Ultimate Guide to Oak in Winemaking.

  • Loess: a type of sedimentary soil formed by the continuous deposition of sand and clay, often loosely held together by limestone. The majority of this soil is quartz (up to 80%), along with small amounts of feldspar, mica and other minerals. The word is of German origin, meaning 'loose', which defines the nature of this soil: porous and well-drained. Soils rich in loess are a good source of minerals, and generally very fertile.