Sir, Thank you for the article on walnut trees (Country Matters, April 7). It reminds me of the time when living deeper in the countryside than now. There were several omissions from the uses of the walnut. It has several culinary uses including walnut sauce and candied walnut, well known to Mrs Beeton; and most important, pickled walnuts a great delicacy. My father used to do these every year using the soft walnuts in early July from a neighbour's tree. Most important that they are not woody.

Each walnut had to be pricked all over with a fork and then soaked in strong brine for five to seven days. Sometimes another soak in fresh brine makes a better pickle. Handling the pricked walnuts stains the hands brown. Two large, nearly flat dishes were then set out and the walnuts placed on these and then they were put out in the sun, turning occasionally until they became perfectly black. When ready, vinegar was boiled for ten minutes usually malt but sometimes cider vinegar with spices and the hot, not boiling, vinegar poured over the black walnuts in jars. Ready after six weeks, they usually last for two to three years. They are delicious with cold meats and salads. I hope this may help to extend the use of this most useful fruit.

Dr Peter Ferrer, Woodstock