Effect of Temperature in the Evaluation of Yeast Flocculation Ability by the Helm's Method

Production lager yeast strains settle to the bottom at the end of fermentation, but some of them cannot be classified as flocculent according to the Helm's test. This method is one of the most recognized laboratory procedures to evaluate the flocculation ability of yeasts. This assay involves a combination of standing times and ambient temperature (20°C) to permit yeast sedimentation. This article describes the use of several temperatures of analysis (5, 10, 15, and 20°C) during the assay of the Helm's test on some brewing yeast strains. The use of a temperature of 5°C during the analysis increased the volumes of settled yeast obtained in the laboratory, even with yeasts reported as non-flocculent by the regular Helm's conditions.