Koelschip

A Koelschip is a critical component to the lambic brewing process. Koelschips serve two purposes. The first is to spread the wort across a wide surface area and allow it to cool. The second is to enable spontaneous fermentation by introducing the desirable wild yeasts and microorganisms of the Le Senne Valley to the wort. Koelschips often reside in the brewery's highest most point and are positioned next to slatted windows or other openings to allow open access to the beer.

This process can only happen during the cooler months of the year as molds that can have a negative impact on the beer have a difficult time surviving the cold temperatures. It will take the wort a period of about 10 hours to cool to the desired temperature at which point it will be transferred to barrels. The barrels will help continue the innoculation process as microorganisms can live deep within the wood.

Some breweries such as Mort Subite and Belle Vue don't use a koelschip any more. Mort Subite instead uses the Lebeau method and Belle Vue uses the DKZ method.