In order to fully develop their aroma, the blackthorn fruits need the first night frosts. Only then can wonderfully tasting jams, jellies or liqueurs be prepared from the dark blue to black fruits. Why is that?
Why should sloes be harvested after the first frost?
The blackthorn fruit develops its aroma when the first night frosts make the cell walls more permeable and convert the starch into sugar. This makes the hard pulp softer and milder in taste. Blackthorn can be made into jam, wine or liqueur.
Harvesting sloes after the first frost
With its spherical, black-blue color and large stone, the approximately one centimeter large blackthorn fruit is reminiscent of its closest relative, the plum. As finds on Lake Constance show, the people of the Neolithic era valued the tasty fruits as a source of vitamins in the winter months. The Stone Age man Ötzi also carried dried sloes with him when he crossed the Alps.
The greenish flesh of ripe sloes initially tastes very sour and unpleasantly bitter. The first night frosts make the cell walls of the sloe fruit more permeable and the starch of the stone fruits is converted into sugar. This makes the hard pulp softer and the sloes taste significantly milder.
Process sloes correctly
You can harvest the fruits of the blackthorn after the first frost in late October or early November. If you would like to pick the drupe before the first frost, you should freeze the sloes for a few days. However, the taste of the fruit is not quite as intense.
Processing the sloes:
- Wash the fruits well and drain them
- cut in half with a sharp knife
- Remove the stone as it contains small amounts of hydrogen cyanide and should not be consumed
Jam and wine from sloes
Sloes develop their intense, tangy aroma through cooking. You can combine the sour fruits with mild fruits such as apples or pears and make aromatic jams.
From the prepared fruits you can make a traditional sloe wine, which was previously used to stretch and color low-quality red wines. Mix the stone fruit with plenty of sugar and grain and let this mixture steep for at least two months. This drink, known as sloe fire, warms you from the inside in the cold season.
The fruits of the blackthorn – a proven natural medicine
In naturopathy, blackthorn flowers and fruits are used to relieve a wide variety of ailments. Blackthorn contains a lot of tannins, strengthens a weak stomach and relieves inflammation of the gums. Their high vitamin C content makes them an immune-boosting agent for stubborn colds.
Tips & Tricks
The fruits of the blackthorn give off a lot of dye. Due to the tannic acid content, you can dye wool and linen bluish pink with the natural dye without prior staining.
