We saw this at John Lewis. For the price, it’s going to be a lot cheaper to DIY.
Lightly crush coffee beans in a mortar and pestle and drop them into your infusing vessel at a ratio of 1/4 cup beans per 2 cups (500ml) vodka. You can optionally add 1 tbsp brown sugar. Pour vodka over top and seal tightly. Let the coffee beans infuse for 2-4 days.
Place strainer over a bowl. Pour the coffee vodka over the strainer to remove the solid pieces and stop the infusing process. Pour the vodka back into your infusing vessel and seal to store.