The Influence of Elevated Steeping Temperatures on the Resulting Malt Homogeneity and Malt Quality
Achieving a homogenous malt quality within industrial scale malt batches of up to 300 tons is a major goal for the malt industry. Malt analyses represent only small samples and merely give a rough mean score over thousands of kernels. Cytolytically badly modified or even ungerminated kernels may occur consequently leading to lautering and filtration problems e.g. due to high remaining unhydrolysed â-glucan fractions. Published findings claim that relatively low temperatures during steeping and germination (12–17 °C) are required to produce high quality malts, however, these processes consequently take 5 to 7 days excluding the kilning. Most of these studies were carried out several decades ago and new barley varieties with improved malting properties are available now.
In this study, constant steeping temperatures between 15 and 35 °C were used to obtain the influence of the temperature on the germination and thus the resulting malt homogeneity and quality. The use of a steeping temperature of up to 30 °C resulted in faster germination rates, higher germination energies and improved malt qualities as well as increased malt homogeneities in comparison to the reference temperature of 15 °C. Furthermore, the lautering performance of the produced malts, evaluated by a laboratory lautering test, was improved or equal when using a steeping temperature of up to 30 °C. The optimal steeping temperature in the trials was proven to lie between 20 and 25 °C, resulting in a quicker start of the germination promoting an earlier onset of the cytolytic modification of the barley. The malting losses only increased slightly applying higher steeping temperatures and a time reduction of the germination process appears to be possible while similar or better malt qualities can be achieved. The outcome of these trials could help the malting industry to save energy and time.
BrewingScience - Monatsschrift für Brauwissenschaft, 66 (July/August 2013), pp. 114-122
