Why does blackcurrant liqueur taste medicinal, bitter or too spicy?

Expanded Explanation

A medicinal or bitter flavour usually comes from over-extracted cloves, fennel seeds, pink peppercorns or crushed blackcurrant seeds. Five or more cloves, heavily crushed spices, or an infusion kept warm for too long can overpower the fruit. Crushing all the berries can also increase tannin and seed bitterness, especially when the mixture is shaken aggressively.

Remove the spices immediately and strain the infusion if the flavour is already too strong. Let the liquid rest for several days before correcting it, because sharp spice notes often soften after filtration. A small addition of sugar syrup, honey or fresh lemon juice can rebalance the liqueur, but avoid adding large amounts at once.

For a seriously over-spiced batch, blend it with a separately prepared plain blackcurrant-and-vodka infusion. This preserves the fruit character more effectively than excessive sweetening. In future batches, crush only about one-third of the fruit, use two cloves, lightly crack the pink peppercorns and begin tasting the botanicals during the first week.