PALM flat beer
Flat beers from the past, now trendier than ever
Before 1900, the Belgian beer landscape was characterised by (top, mixed and spontaneous fermentation) “flat” beers, which ferment at room temperature with subsequent maturation in oak vats or “foeders” at ambient pressure. The carbon dioxide content (CO2 – a by-product of alcoholic fermentation) in solution is thus in balance with ambient temperature and pressure, such that the beer does not effervesce in the glass. It therefore looks “flat”, comparable to water.
Bottom-fermentation beers (Pilsner lagers) have been in the ascendant since the beginning of the 20th century, using refrigerating machinery that enabled fermentation to take place at low temperature (5 to 10°C) and lagering at 0°C. Using these low temperatures and pressurised lagering tanks increased the amount of carbon dioxide dissolved in the beer, providing strong effervescence in the glass when the beer was exposed to ambient pressure. Compare this with a bottle of sparkling water, which does not effervesce in a closed bottle but does so as soon as it is poured into a glass.
The consumption of carbonated drinks is dropping globally:
- Flat water sells better than sparkling water
- Lemonades are being replaced by fruit juices
This why the “Old Masters” are trendier than ever!
Pouring flat beers
Appearances are important too!
Flat beers are very digestible and moreover they spare you that bloated feeling in your stomach. However, a nice head looks good, which is why OLD MASTERS are served through a nozzle spraying fine jets of beer that absorb nitrogen from the air.
The emulsion of fine bubbles of nitrogen gives the beer a milky appearance (1) in the glass that rises gradually (2) to reveal the true look of the beer as it forms a very stable and creamy head (3) (keg dispensing pressure with a 30% CO2/70% nitrogen/gas mix, 0.35 bar on gauge).