Lambic
Lambics are spontaneously fermented beers native to the Senne Vally and Pajottenland regions of Belgium. Lambics are made from barley malt and unmalted wheat (30-40%) and aged hops. They form the base of a number of lambic products including unblended lambic, gueuze,fruit lambics including kriek and framboise, and faro. Lambic (and the lambic products Gueuze and Kriek) labeled 'Oude' or 'Vielle' are protected in the EU and are required by law to meet certain conditions including average age, minimum OG, max pH, max bitterness, max isoamyl acetate level [1]. In practice the presence or absence of this term can help the consumer determine which products will likely be back-sweetened and which will be traditional, though some notable producers do not follow this nomenclature.
See the spontaneous fermentation page for more info on lambic and other spontaneously fermented beers.
Production Methods
in progress Lambic is brewed only in the fall and winter (generally from roughly October through March). Specific producers have differing feeling 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 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.
Mashing and Boiling
Lambic grist is composed of a barley malt such as pilsner malt and a large percentage of unmalted wheat (30-40%). This grist is carried through a multi-step, labor intensive multi-step mashing process known as a turbid mash. During turbid mashing, a portion of unconverted starchy wort is removed from the mash and heated to denature the enzymes. This starchy wort is carried to the boil without full conversion and it supplies wild yeasts and bacteria with carbohydrates that Saccharomyces cannot ferment.
This starchy wort then goes through a long boil (on the order of 4 hours) where it is heavily hopped with aged hops (on the order of 2.5-3g/l [2](~49 minutes in)).
Cooling and Fermentation
Lambics are spontaneously fermented, meaning that they do not receive any pitched cultures. Hot lambic wort is pumped from the biol 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 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.
Blending
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 blender and all but one of the current lambic blenders buy their wort from more than one producer.
Packaged unblended lambic is available from some producers. Notably Cantillon (Grand Cru Brucsella, noteworthy in that it is a 3 year old lambic), Girardin (lambic bag in a box) and Oud Beersel (lambic bag in a box ~1-2 years old), and De Cam Oud Lambiek (3 years old). Lambic from other producers is available by the glass in select cafes in Belgium.
Types
Unblended
A spontaneously fermented unblended beer that is indigenous to the Senne Valley and Pajottenland of Belgium. The flavor is dominated with a unique tartness and brettanomyces character from the wild yeast and bacteria that inoculate the brew. Unblended lambics are not carbonated, though some bottled products may develop carbonation over time. At very young age (months), lambics may have significant undesirable characteristics and may even be undrinkable. This generally passes with time as intermediates are re-processed and/or converted into more desirable characters. Younger lambics have less acidity than older lambics. Old lambics may display more prominent barrel character.
Average alcohol by volume (abv) range: 5.0-7.0%
Gueuze
Gueuze (also written geuze) is a blend of lambics, traditionally 1 year old, 2 year old and 3 year old which undergoes bottle conditioning to become a highly carbonated product. Some producers release blends labeled gueuze that involve blends of lambics of different ages than 1, 2 and 3 years. Not all producers follow the oude/vielle protected name designation and some traditional gueuze can be found without the label Oude or Vielle. Gueuze is generally highly carbonated from either the presence of unfermented material in one of the blend components, the addition of priming sugar, or both.
Fruit
In the case of Fruit Lambics, whole fruits are traditionally added after the visibly active stage of spontaneous fermentation has finished. Some producers choose to add fruit to an older lambic (1-2 years old) while others choose a younger lambic (< 1 year). Kriek (cherries) and Frambroise (raspberries) are the most common fruit lambics, although other fruit lambics can be found including plum (e.g. Tilquin Quetsche), Apricot (e.g. Cantillon Fou Foune), wine grape (e.g Cantillon St. Lamvinus and Vigneronne) strawberry (e.g Hanssens Oudbeitje) among others. Once the fruit is added, the beer is subjected to additional maturation before (generally) blending in unfruited lambic and bottling. Alcohol content tends to be around 6%, although certain fruits such as grapes may raise the abv. Bottled fruit lambics are typically carbonated, though some uncarbonated fruit lambics can be found. Some fruit lambic is also available as bag ina box (Girardin Kriek).
A number of non-traditional sweetened fruit lambics can be found. These may sometimes be identified by especially low abv (<3%). Breweries producing sweetened lambics frequently use fruit / sugar syrups rather than whole fruits.
Average alcohol by volume (abv) range: 4.0-7.0%
Lambic outside of Belgium?
In the EU, lambic must be a spontaneously fermented product. That means that any beer receiving any pitched microbes (from lab cultures or bottle dregs) cannot be called lambic. While lambic has no legal protection outside of the EU and EU laws do not give lambic a regional designation (unlike other alcoholic products such as Champagne and Kölsch), many brewers outside of Belgium chose not to call their spontaneous beers lambic out of respect for the Belgian lambic tradition. Some brewers choose names alluding to lambic such as Sonambic or label their spontaneously fermented beers with the term Coolship to convey to consumers that their lambic-inspired beers are spontaneously fermented and follow parts of the lambic tradition without actually using the terms lambic or gueuze [3] (~6 min in). See also Dan's youtube video discussing using the term lambic.
See Also
Additional Articles on MTF Wiki
External Resources
- "Flemish Red Brown Beers", Presentation by Rudi Ghequire at CBC 2012. (Contains differences with Lambic)
- lambic.info