I think these maybe Bullace which come in yellow and purple varieties. They are slightly larger than a cherry but smaller than a cherry plum. The yellow ones have a slight pink tinge on one side but never turn red. They have a single stone which does not come out easily. The purple type are smaller and very like sloes but the bush is not prickly. They all make excellent james and jellies but are lovely in gin or vodka after about three months infusing.
