Hydrate the gelatin powder in the water. Cook the caster sugar, the smaller portion of invert sugar and the blackcurrant purée at 230°F (110°C). In the bowl of a stand mixer, combine the cooked syrup with the remaining invert sugar and the bergamot purée. Melt the gelatin in the microwave, then combine with the hot syrup mixture. Beat until a ribbon forms. Immediately pour the marshmallow at 95-105°F (35-40°C ) into a frame. Store in a dry place.
