''Main article: [[Brewing Lambic]]''
Though there are industrial-scale lambic breweries with very large production runs, the main ingredients always consist of pale two-row malt (approximately 2/3 of the bill), unmlated unmalted wheat (approximately 1/3 of the bill), aged hops, wheat, water, and microbial flora. When the wort is ready, it is transferred into the [[koelschip]] to cool and become inoculated for a twenty-four hour period and then transferred to the oak barrels where it will continue to develop until it is either blended into [[Gueuze/Geuze|gueuze]] or used in a variety of other [[Main_Page#Styles|lambic styles]]. There have been significant changes in the brewing process since the 19th century, according to Guinard <ref name="Guinard">Jean-Xavier Guinard, [[Books#Classic Beer Styles: Lambic|Classic Beer Styles: Lambic]], 1990</ref> including the ratio of malt to wheat, mash temperatures, and controls on the exposure of the wort before being transferred to barrels. Today, the traditional process has been mostly standardized among the traditional brewers.
<ref name="HopDuvelMenu">Lambic Digest, June 8, 1994, http://192.185.42.233/lambic-listserv/1994/366.txt</ref>