Improving brewery yeast propagations.

A supply of good quality, healthy yeast is essential to the efficient running of any brewery. Although each fermentation will result in the generation of three to four times the biomass that it started with, and even though often reused, this does not tend to happen in perpetuity. On a regular basis, breweries will bring in small quantities of new yeast, which will then need to be propagated in multiple stages from a slope, up to the several hundred or thousand litres required for fermentation. A single use bioreactor system has been tested for its ability to replace some of these propagation steps, speeding up the propagation process and minimising the opportunity for contamination by other, undesirable, microorganisms.