Oud Beersel is a Belgian gueuze blendery and historic lambic producer based in Beersel, approximately ten kilometers southwest of central Brussels. Its predecessor was founded by Henri Vandervelden in 1882 when he built a house, brewery, and supporting facilities on a site in Kasteelstraat. The business remained under the management of the Vandervelden family for four generations, while the name Oud Beersel was introduced in 1954. The producer specialized in lambic, gueuze, and kriek made through the traditional spontaneous fermentation associated with Pajottenland and the Senne Valley. The brewery and its adjoining public house closed at the end of 2002 because no successor was available and market conditions had become increasingly difficult. Gert Christiaens subsequently decided to revive the operation and spent several years learning lambic production and blending from Henri Vandervelden. The new Oud Beersel company was established in July 2005, and the site officially reopened in November of that year. Its current production model involves cooperation with partner breweries that provide wort made according to Oud Beersel’s specifications. The spontaneously fermented lambic is transported to Beersel, where it matures for up to three years in wooden barrels and large foeders. Lambics of different ages and characteristics are blended to produce Oude Geuze, while Oude Kriek is made by fermenting sour cherries in lambic followed by secondary fermentation in the bottle. The core range includes Oude Geuze Vieille, Oude Kriek Vieille, and various unblended, fruit-based, and infused lambics. The company also produces the Bersalis range, whose sales initially helped finance the revival of traditional lambic production.