The Lager: so laid back it’s horizontal.

The release of The Lager marks the final step in the development of our process to brew the best lager we possibly can. We began brewing lager towards the end of 2017, and from the outset we knew that we wanted to do things properly. This started with the recipe and choice of ingredients, followed by the all important focus on temperature and time. A lager is truly made during its long, cold maturation phase, during which the yeast cleans up the beer and pulls all the flavours together to create a perfect, harmonious beer.

“We knew that we were missing one crucial component; horizontal tanks.”

We were able to manage these aspects at our Bermondsey site using the equipment we had, and by the end of 2019 were brewing lagers that we were really quite happy with. However, we knew that we were missing one crucial component; horizontal tanks. Thanks to our crowdfunding campaign we were able to make the investment and purchase four 26HL horizontal lagering tanks, which are now installed and operational at our Croydon brewery. 

Carrying out the maturation phase of a lager in horizontal tanks is the way the masters do it, and have done so for generations. Needless to say, it has a number of important benefits. 

Firstly, moving the beer from an upright unitank to a horizontal lagering tank dramatically reduces the hydrostatic pressure exerted on the yeast. This pressure stresses the yeast, inhibiting its ability to carry out its functions in a clean, efficient way. Things happen slowly during this phase, as the yeast is coming to the end of its cycle within the beer. The more comfortable the environment for the yeast, the easier it will find it to carry out its work, and the finer the resulting beer will be. 

Secondly, the long, relatively flat bottom on the tanks provide a greater surface area of contact between the settled yeast and the maturing beer when compared to an upright unitank. This enables more yeast to work on the beer, cleaning it up and bringing all of the flavours together. 

Finally, by turning the beer on its side, there is less distance for yeast, proteins and other solids to travel to drop out of suspension, leaving the beer crystal clear. Our lager is unfined, unfiltered, yet completely clear. 

Horizontal tanks therefore play a crucial role in the final stages of a lager brew. Once the primary fermentation has finished and the beer is essentially made, the temperature is dropped and the beer is moved over. For the next 4-6 weeks the beer will sit at between 0 - 2 degrees centigrade as the yeast gradually cleans up any ‘green’ flavours and pulls the beer together into one, harmonious, delicious drink.

“Brauerei Heller in Bamberg lager their Schlenkerla beers in the caves of a 700 year old tunnel system - I’ve been down there, it’s freezing!”

From a historical context, there is also a very practical consideration that may well explain the use of horizontal tanks in lager brewing. Due to the need for lower temperatures, lager breweries would dig cellars underground or into the sides of hills to create cool, steady environments for the beer to mature in. Blocks of ice cut from rivers and lakes would be dragged into the cellars to further bring the temperature down. (For example, Brauerei Heller in Bamberg lager their Schlenkerla beers in the caves of a 700 year old tunnel system - I’ve been down there, it’s freezing!) Clearly a horizontal storage vessel would be desirable in this setting - firstly vertical tanks would require much higher ceilings to be cut/dug in order to accommodate them when compared with horizontals, and secondly, lower ceilings would result in less stratification of the air, thus helping to maintain a consistent, cool temperature. 

It may well be the case that the flavour/quality benefits of horizontal tanks came along as a happy accident, secondary to these practical considerations, or indeed that over the years the yeast used adapted to their environment and hence only perform at their best in a horizontal setting.

“A tank alone will not make a beer great, and our horizontals are just one part of our process”

Whatever the story behind horizontal tanks, one thing is for sure; they are integral to the production of the finest lager possible. A tank alone will not make a beer great. Our horizontals are just one part of our process, every step of which is designed to produce the best lager we can possibly make.  

P.s. Once the taproom is reopened we will be running pipework from the horizontals directly to the taps, enabling us to serve our lagers directly from the tank. Only, of course, when they are ready!