Ah yes, Mr Red, I'd forgotten about gluten. Do you remember those strange crispy rolls called Energen? I wonder if they still sell them. I believe they were gluten-free.
In 'Domestic Science' at school, we were told to take a handful of flour and rinse it under the tap while squeezing it. The water washed away all the starch, and what was left (a delightful squishy mess) was apparently gluten. I tried this at home and got a clip round the ear from Ma, for wasting good flour!