By Rob Mccaig, Chief Brewer of Europe – SAB Miller
In China, a brewer was complaining about poor quality malt coming from Canada. The issue was with premature flocculation of yeast resulting in poor attenuation. This only occurred during the spring in the brewery, malt was fine the rest of the year, but the brewer believed it was the malt’s fault. Upon evaluation of the brewery process, it was shown that the brewery did not treat their water, using water for the brewery from a local spring. In the spring period, the higher flow rates from the spring resulted in a change in the water mineral content – the calcium levels were far lower affecting the final wort calcium and hence yeast flocculation.