BEER STYLES
the kombucha process needs oxygen and produces a lot of acetic acid but that does not stop US brewers from having a go. If all the above fails you will have to buy a coolship, leave the windows open and get a lot of wooden casks! Just a nal caution, if you are making traditional beers and sour ones on the same premises – even in separate buildings – you must keep the processes entirely separate and that means people as well as equipment. I’ll leave the nal word to BrewDog’s Richard Kilcullen “People are ready for these products. We have to get people willing to try them and get them excited about sampling something new. This will not be hipsters following the latest fad but a genuine curiosity into enhanced acidity and exotic fruit combinations.
A handful of malt can be replaced by a lactic culture but it is best not to try and sour a mash of acidulated malt if you are expecting to produce a drink- able beer! A pH meter is obligatory to track the acidity to the required level. Souring in fermenter would classi- cally involve a cell count ratio of yeast to bacteria of between 4:1 and 6:1 but today it is closer to 1:1. Brewers usually add the yeast rst, allow it to attenuate by around two thirds before adding an actively fermenting acid addition. Otherwise the dormant bacteria can be added at pitch with their lag phase over by two thirds gravity. In the US you will see kombucha ‘beer’ where the fermenting agent is a SCOBY (symbi- otic colony of bacteria and yeast) but the substrate is tea rather than wort and most are souped-up with fruity additions. Brewers should beware that
Remember to keep your lactic acid bacteria well away from your less traditional brew plant!
“It is much easier today as folk are used to acidity in wine and the cider industry has introduced the public to fruity combos. The demand is there, people are ready for them.”
TIMMERMANS
Timmermans in Itterbeek, Belgium has kept the tradition of the true lambic alive for over 300 years. Its beers have been brewed in the oldest active lambic brewery since 1702. Wort, mashed with 30% wheat and aged hops, is cooled to around 23° in a coolship. The brewing of Lambic beer is a seasonal activity, which means they are brewed only between September and May. If the outside temperature is too high (>15°C) there are too many unwanted bac- teria in the air, which has a negative impact on fermentation.
The cellar at Timmermans: there are two types of barrels in the maturing room: The Foudres (currently 4,000 litres) were reconstructed by expert coopers in Portugal from the ‘old’ foudres (6,000 litres). The Pipes (600 to 650 litres) are barrels originating from Porto, are entirely made of oak and are mainly used for the old Lambic beers Oude Gueuze and Oude Kriek
The mash tun has a series of perforated copper discs called the ‘Madammen’ system. These revolve cutting the mash and allow a coarse ltration via the holes in the discs. A portion of the wort is then boiled prior to adding back to increase the temperature
The Timmermans coolship, alongside louvred windows to encourage exposure to the air followed by spontaneous fermentation. (Photos: Ian Hornsey)
The Timmermans malt mill
october 2019 I BREWER AND DISTILLER INTERNATIONAL ● 33
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