Trying to find out the age of the wheat used in some local mills has become a minefield! not one adequate answer. Since you use local wheat & since this year's harvest is supposedly the best for some time, can i assume that in your wholemeal bread flour its' english wheat content is from this year's harvest? Apologies for such a direct question, but am having unespected gut problems & hoping to in part understand what's causing them?
The age of wheat has nothing to do with it. Our wheat is all from the 2014 harvest. There was little carryover this year from the previous year. The levels of gluten in the wheat is much lower this year.
You say unexpected gut problems, is this with bread? Most people find that eating lower gluten products like French, spelt or soda type breads can help.
Remember that everyone puts spin on what they are writing and you can find research that will substantiate any theory. Wheat needs to be stored below 15% moisture otherwise it can overheat and go off, resulting in unpleasant odours. It also can destroy the gluten and cause the starch to convert to sugar making fermentation in bread impossible. Every harvest is different according to the weather. Damp growing conditions can cause problems especially around flowering. Fusarium Micotxoins form and some are carcinogenic. The industry tests for them every harvest. This year was low but 2008 25% wheat crop was carcinogenic and could not be used for food. The year before last some wheat had a Fusarium at high levels that affected the dough rheology.