There are also thickets of juniper, boxwood, sloes, holly and cistus. Hazel nuts, apples, pears, sloes and acorns were collected. Sloe gin is a British red liqueur made with gin and sloes. This effect can be reproduced by freezing harvested sloes. Sloes, mulberries and blackberries were also available. Vodka can also be infused with sloes. Each year the winner is crowned the "Grand Master of the Sloes". In Poland, is an infusion () of sloes in vodka or rectified spirit. A modern variation is to pick the sloes earlier and freeze them. In 2017, Serbia was the 5th largest producer of plums and sloes in the world. The traditional way of making sloe gin is to soak the sloes in gin. Sloes preserved in vinegar are similar in taste to Japanese "umeboshi". In Navarre, Spain, a popular liqueur called "" is made with sloes. Sloes can also be made into jam, chutney, and used in fruit pies. Sloes are thin-fleshed, with a very strongly astringent flavour when fresh.