Well it seems I have got to the bottom of my problem with my spelt bread not being baked through to the middle despite considerable lengths of time in the oven. So I thought I'd pass this on to anyone else who might encounter similar difficulties in the future.
Just a bit of background. We've been baking spelt bread for the past 2 years and although it took a while to get the recipe right we eventually did and the results were very pleasing. Then suddenly five or six weeks ago I started getting complaints from customers that the loaves weren't cooked right through and indeed on investigation I found a large doughy sticky lump in the middle of several loaves despite using the tried and tested recipe and baking until all my (admittedly limited) experience was telling me that it was done. Looked done - sounded done - over 100C according to the probe thermometer. I couldn't understand it.
Then a conversation with our miller, Mervin Austin at Mount Pleasant Windmill, Kirton in Lindsay provided the answer. He is an experienced baker himself and on hearing the symptoms immediately recognised that they were caused by "Hagberg" - a condition in the flour created by grain starting to sprout prior to milling.
Basically, if there is a period of wet conditions the grain may start the germination process prior to harvest. This converts starches into sugars & you get a high level of alpha amylase. This can be tested for but this particular batch was not apparently. The high sugar levels make it more gluteous & sticky, resulting in a glutinous crumb. This Hagberg breaks down the protein. Hence our problem with baking it. Basically it is a seasonal thing that you cant do anything about unless the farmer tests in order to keep this out of the system (although the tests are not 100% reliable and the condition may only affect part of a crop).
So if you find you are getting inexplicable problems with uncooked bread - maybe this is the reason... Thanks to all our customers for their feedback and the general support you have given Cat Lane Bakery as it has established itself. Do please let us know of any problems you have with the bread - we're still learning and if we don't hear what's going wrong we can't do anything about it!