Are small starch granules ruining the benefits of high gravity brewing?

The mashing process has to maintain a complex balance between starch gelatinisation and thermal inactivation of starch-hydrolysing enzymes. This balance can be affected by the intrinsic starch granule properties, extrinsic factors such as the presence of sugars and other wort components and the process parameters such as mashing thickness and the temperature-time profile. Nowadays, breweries can use high gravity brewing, which improves brewhouse efficiency. However, large proportions of small starch granules in barley malt seem to endanger this benefit. While in the past, the impact of small starch granules on the mashing process was considered neglectable because their levels in barley malt were deemed low, recent findings showed small starch granule proportions of up to 27 V/V%. Therefore, their importance during mashing has to be reconsidered. In this work, the intrinsic starch gelatinisation behaviour of barley malt starch and the impact of mash thickness on the gelatinisation of small and...