Certain barrels attain such a pinnacle that the decision is made to keep them as is, no blending, continue to age as is and to bottle. These are the rare Fûts Uniques, or Single Barrels, from a given year, often from a single varietal. A special label states the number of the barrel and the number of bottles produced, which is no more than 550 to 600 bottles since the barrel holds 420 litres.