For each 1 imperial pint (570 ml) of sloes, 4 ounces (110 g) of sugar is used, then the jar is filled with gin, adding a few cloves and a small stick of cinnamon, as well as the almond essence. The jar is sealed and turned several times to mix, then stored in a cool, dark place. It is turned every day for the first two weeks, then each week, until at least three months have passed.
The gin will now be a deep ruby red. The liqueur is poured off and the berries and spices discarded. Alternatively, the leftover berries can be infused in cider, made into jam, used as a basis for a chutney, or a filling for liqueur chocolates. The liqueur can be filtered, but it is best decanted back into clean containers and left to stand for another week. Careful decanting can then ensure that almost all sediment is eliminated, leaving a clear liqueur.
Made in this way, the alcohol extracts an almond-like essence from the sloes, this comes from the sloe stones; this avoids the need to add almond essence. Homemade sloe gin is a much more complex and subtle drink than that produced commercially, and recipes will vary depending on the maker's taste. The sweetness can be adjusted to taste at the end, but sufficient sugar is required at the start of the process to ensure full extraction of flavour from the sloes.
In Germany and other German speaking countries, a very similar liqueur is called Schlehenfeuer (literally, "sloe fire"), but in the English speaking world, Schlehenfeuer is generally considered German sloe gin. Schlehenfeuer has an alcohol content of about 38% by volume, and this higher alcohol content is also the most important difference between Schlehenfeuer and other sloe gins. However, Schlehenfeuer and other types of Schlehenlikör (the generic German term for any kind of sloe liqueur) are sometimes made with vodka or rum. The most popular commercial brand of Schlehenfeuer, based on white rum, is made by Mast-Jägermeister AG, better known for its product Jägermeister.
In Spain, pacharan is made by soaking sloe berries in an anise-flavoured spirit, resulting in a light reddish-brown sweet liquid, around 25-30% alcohol by volume. In Italy, Bargnolino is made by soaking sloe berries with sugar and spices in spirit (recipe varies locally), resulting a reddish sweet liquor, around 40-45% alcohol by volume often chilled before serving.
Sloe gin is also known as Sloe or Schlehen Wine and in old colonial communities, simply as SOS wine.
Slider is a Devonshire tradition and uses the used sloe berries from the sloe gin to steep in still cider, making sloe-flavoured cider.Sloe Whisky and Sloe Brandy are variants on the tradition and are often mixed with ginger beer or ginger ale.
To make sloe gin, the sloe berries must be ripe. In the Northern Hemisphere they were traditionally picked in late October or early November after the first frost of winter. A wide-necked jar that can be sealed is needed. Each berry is pricked, and the wide necked jar is filled half way with the pricked berries. Folklore has it that when making sloe gin, one should not prick the berries with a metal fork, unless it is made of silver. The established traditional method is to prick the berries with a thorn taken from the blackthorn bush on which they grow.