The issue with skinning
Spring malting barley has not had the easiest of years, a wet harvest has meant that grain quality has been tested and the issue of skinning has reared it’s ugly head again.
Skinning happens when the outer layer of the grain or husk doesn’t adhere or glue to the main body of the grain (caryopsis). It often occurs after a period of wet followed by dry weather multiple times during harvest. The grain husk becomes loosened and skinning or split husks can occur. This can cause issues during the malting process, as grains germinate at different rates, or sometime in the case of fully skinned grains, don’t germinate at all.
Bigger, bolder grained varieties can show elevated levels in some years, and there is some evidence that more modern varieties may have less adhesive properties, but the major factor is weather, and if skinning occurs, it often affects most modern varieties. For breeders, it is not straightforward to get the balance between bold grain with low screenings and reduced skinning. However initial results from Syngenta 2020 trials over 3 sites in Scotland, shows our new variety SY Tungsten may be getting closer to the mark, with lower levels of skinning than both Laureate and LG Diablo.
It is encouraging to see varietal improvements, but there are other ways to mitigate high levels of skinning: combine set up can ensure as little as possible physical damage happens to the grain during harvest. An AHDB project into skinning published in March 2018 found that increased drum speed and increase concave tightness correlated with an increase in skinning. Good storage and drying also help to reduce levels as well as maintaining other quality parameters required for malting barley.