The stages of brewing our lambic beers
STAGE 1Brewing
A room called the grist mill houses the mills that grind the malt
and wheat before they are brought to the brewhouse.
Next to this building is the old brewhouse that was built in
1856. The facade dates back to 1869 but, curiously, it was
the 9681 vintage that was sealed in there... Had the workers
who made the façade had too much lambic to drink? The oldbrewhouse is home to a beautiful open red cast iron vat, thepredecessor of today’s mash tuns. This is where the «madams»
could be found: large perforated plates that, when they were inmotion, were reminiscent of how ladies’ posteriors would sway
as they walked.
The current brewhouse was built in 1992 and has a capacityof 18,000 litres of wort per brew. The pumps, valves and mixer
that produce the brew are on the ground floor. On the upper
level of the brewhouse are four spectacular copper vats: themash tun, the maisch vat, the filtration vat and the boiling vat.

The Maisch vat

The mash tun

The boiling vat

The sugars necessary for producing beer are extracted fromthe ground grains in the mash tun (70% malted barley and 30%
wheat). The brewing water and the grains form a paste that isbrought to a variety of temperature levels with the addition ofwater at each level. This allows the starch to be extracted fromthe grains, producing a milky solution. At 78 °C, the starch isconverted into fermentable sugars by the action of enzymes.
These are the sugars that will subsequently be converted (byfermentation) into alcohol flavour and aroma components.

Once the wort has passed into the boiling vat, the cooking
phase can begin. Hops that are more than one year old areadded during the cooking phase. This will ensure that thelambic can be kept for a longer period of time.
The exact cooking time (between three and four hours) depends
on the wind and density of the evaporating vapour. Before
being poured into the cooling tray, 10% of the brew (more than2,000 litres of total 22,000 litres!) disappears as a vapour. Thisevaporating vapour is poetically called ‘the angels’ share’...

The milky solution produced in the mash tun is transferred
via two pumps to the Maisch vat. In this vat, the temperature
will be increased to 90 °C, thereby stopping the enzyme
action and allowing some of the starch to not be converted
into fermentable sugars. This makes it easier to monitor thefermentation process later on.
The filtration vat
The filtration vat is where the insoluble components of thegrains (the hull) are separated from the sugar solution (thewort). The hull is deposited onto filtration plates and forms acake that filters the wort which then goes into a pot. Residue(slop) are sold as livestock feed to farmers in the region.

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The stages of brewing our lambic beers
STAGE 2STAGE 4

Fermentation

Blending

After cooking, the wort is brought to the huge cooling tray
nearby. This is the most mysterious aspect of lambic brewing. At
night, the wind and the local microflora inoculate wild yeast into
the wort which is cooling. Since this happens without humanintervention, it is called beer of spontaneous fermentation. The
cooling tray is essential to the production of lambic. The nextday, the wort is pumped to the fermentation vats.
Through a variety of successive fermentations, the wort slowlyturns into lambic. This occurs in large oak barrels (foudres)or stainless steel vats to which are added wood chips, likein the wine industry. During the first six to seven months,
fermentation converts the sugars into alcohol, taste and aroma
components.

In order to produce our old gueuze, we blend old and young
lambic that has matured in large oak barrels called foudres.
Young lambic still contains enough yeast and sugars tocontinue to ferment in the bottle.
Old kriek does not require any blending. After the cherries
ferment for six months in a lambic that is at least six months old,
old kriek is directly bottled for a second fermentation process.
In order to produce our other fruit beers, a fresh juice of
exceptional quality is blended with a young lambic that isat least one year old. This mixture will again ferment andmacerate for up to 3 days. In this case the same wild yeastthat are still left in the mix will continue to react with the sugar
contains in the blended beer.

STAGE 3STAGE 5After the fermentation process, it is time for the maturation
process, which lasts at least six additional months, but which
can also last for several years. It is during this stage that thecharacteristic taste of an old lambic develops.
Since lambic must undergo several months or even severalyears of fermentation and maturation, a lambic brewery musthave enough storage space. Lindemans Brewery always has
more than 6 million litres fermenting and maturing, which isthe equivalent of 24 million glasses of beer.

After the lambic has been meticulously blended or mixed, itgoes to the bottling workshops which have been operational
since 2003 and 2014. Every day, thousands of bottles are filledautomatically in the best conditions and in a spotlessly clean
environment.

Maturation

Bottling

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