Changes

in progressLambic is brewed only in the fall and winter (generally from roughly October through March). Specific producers have differing feeling feelings on when production can begin (some look for nights of 8C or cooler, others look for the first frost). The reason generally given for brewing lambic only in the fall and winter is for the proper ambient balance of microbes, though it also has to do with appropriate cooling overnight since ambient exposure is the only cooling form used in a traditional lambic. Additionally, inappropriate cooling overnight may favor the metabolism of undesirable thermophilic microorganisms, which could act in combination with the ambient microbe balance to result in the necessary fall and winter time window for lambic production.

Lambics are spontaneously fermented, meaning that they do not receive any pitched cultures. Hot lambic wort is pumped from the boil kettle to a [[coolship]], a shallow vessel with a large surface area to volume ratio, where it cools overnight open to the air. During this time the beer is inoculated with microorganisms from the environment and resident in the brewery. Lambic is only brewed the late fall, winter , and early spring when nighttime temperatures are sufficiently low to cool the wort appropriately overnight. The morning after cooling the lambic wort is transfered transferred to barrels or foeders where fermentation occurs slowly over the course of months to years. Lambic fermentation is characterized by distinct phases when different microbes are active.

Lambic is traditionally blended (with other lambic and/or with lambic aged on fruit) before being sold, and it is uncommon to find straight (unblended) lambic for sale.In the lambic producing world, there are both blenders and brewers. Brewers produce lambic wort and all of the current brewers also blend their lambic. Blenders do not have a brewing facility and buy wort from other producers. This wort has been inoculated in the brewers coolship and is delivered to the blenders on the morning after brewing, where it is aged in the blender's barrels. There are currently 4 main lambic brewers supplying their wort to a blender and all but one of the current lambic blenders buy their wort from more than one producer.