NASA is indeed interested in the questions raised by brewing beer in a microgravity environment.
Scientists who study the physics of gas-liquid mixtures would like to understand, for example, what happens when there is no buoyancy to bring the bubbles to the surface of a fizzy liquid, and the characteristics of fermentation in microgravity.
Two separate space shuttle experiments tackled these questions.
The first investigated how well yeast performs in orbital free fall, not only to see if brewing space-beer might be possible, but also to provide valuable information to pharmaceutical companies with a keen interest in the biology of orbiting microbes.
The space-beer turned out essentially the same as that brewed on Earth.
Its specific gravity and the yeast’s performance when used to brew subsequent batches of beer was comparable to that of control samples on Earth.
However, the total yeast cell count and the percentage of live cells in the space sample were lower. Despite this, the fermentation was significantly more efficient.
This raises the question of whether we can modify the fermentation process, or the yeast itself, to reproduce this effect on Earth.
The second experiment, flown on the shuttle by the Coca-Cola Company, was to test its system for dispensing Coke in a weightless environment.
The challenge was to dispense a fizzy beverage yet keep the gas in solution until the cola is drunk. Because bubbles don’t rise in free-fall, changes in temperature, pressure, or even physical agitation tend to cause the whole thing to degenerate into a foamy mess.
A computer-controlled device adjusted the temperature of the drink during mixing and dispensing, and minimized agitation by dispensing the drink into a collapsible bag inside a pressurized bottle.
The pressure around the bag was slowly released as it filled with drink, keeping the drink under constant pressure and preventing the gas from coming out of solution too quickly.
The end result was a space version of the world-famous fizzy drink.
