The "Bordeaux blend" of Cabernet Sauvignon, Merlot and Cabernet franc, with potentially some Malbec, Petit Verdot or Carménère, is the classic example of blended Cabernet Sauvignon, emulated in the United States with wines produced under the "Meritage" designation. But Cabernet Sauvignon can be blended with a variety of grapes such as Shiraz, Tempranillo and Sangiovese. The decision to blend is then followed by the decision of when to do the blending—before, during or after fermentation. Due to the different fermentation styles of the grapes, many producers will ferment and age each grape variety separately and blend the wine shortly before bottling. The Cabernet Sauvignon grape itself is very small, with a thick skin, creating a high 1:12 ratio of seed (pip) to fruit (pulp). From these elements, the high proportions of phenols and tannins can have a stark influence on the structure and flavour of the wine—especially if the must is subjected to long periods of maceration (skin contact) before fermentation. In Bordeaux, the maceration period was traditionally three weeks, which gave the winemaking staff enough time to close down the estate after harvest to take a hunting holiday. These long maceration periods result in very tannic and flavorful wines that require years of ageing. Wine producers wishing to make a wine more approachable within a couple of years will drastically reduce the maceration time to as few days. Following maceration, the Cabernet must be fermented at high temperatures of up to 30 °C (86 °F). The fermentation temperature will play a role in the result, with deeper colours and more flavour components being extracted at higher temperatures while more fruit flavours are maintained at a lower temperature. In Australia, there has been experimentation with carbonic maceration to make softer, fruity Cabernet Sauvignon wines. The tannic nature of Cabernet Sauvignon is an important winemaking consideration. As the must is exposed to prolonged maceration periods, more tannins are extracted from the skin and will be present in the resulting wine. If winemakers choose not to shorten the period of maceration in favour of maximizing colour and flavour concentrations, there are some methods that they can use to soften tannin levels. A common method is oak ageing, which exposes the wine to gradual levels of oxidation that can mellow the harsh grape tannins as well as introduce softer "wood tannins". The choice of fining agents can also reduce tannins with gelatin and