This method describes how to determine development of the acrospire in malt kernels. The method provides an overview of the uniformity of germination.
Malt intended for use in beer brewing or elsewhere in the food industry.
Visual method
Barley intended for the production of malt is evaluated with regard to pre-germination.
Visible pre-germination is evident at the rootlet and is therefore grounds for rejecting a barley lot. However, after the barley is cleaned and the rootlets are removed, the so-called “hidden pre-germination” can be made visible using the staining methods described below.
Kernels suspected of having pre-germinated are boiled for ½−1 min in a 20 % solution of copper sulfate, allowed to remain for 30 min in the hot solution and are subsequently rinsed with water. The acrospire is stained green, making it clearly visible.
Barley intended for the production of malt is evaluated with regard to pre-germination.
Kernels suspected of having pre-germinated are boiled in water and then allowed to remain in cold water for some time. Thereby, the husks become transparent, making the embryo and the acrospire, if present, visible.