How long should black Vietnamese coffee infuse in vodka before it turns bitter?

Expanded Explanation

For this recipe, 48 hours is a strong starting point because the coffee needs enough time to release deep roasted flavour without becoming harsh. Coarsely crushing the beans helps extraction move faster, so the coffee character comes through clearly even within a short infusion. This timing keeps the profile bold and aromatic rather than burnt or over-extracted.

If the beans stay in the alcohol too long, bitterness can quickly take over, especially when paired with toasted coconut and roasted almonds. The pleasant dark-roast notes can shift into dry, ashy, or overly sharp flavours that sugar cannot fully hide later. In most cases, it is safer to strain earlier and adjust sweetness afterward than to leave the coffee in too long.

Taste the infusion after about 36 hours and again near 48 hours if possible. Once the coffee tastes rich, full, and balanced, strain it immediately. If you want a slightly softer profile, use whole or lightly cracked beans rather than finely crushed coffee, because fine particles can over-extract and also make filtering much harder.