Pour 200 ml of cold water into a small bowl. Evenly sprinkle the gelatin powder over the surface, stir gently, and allow it to bloom for 5–10 minutes until fully hydrated.

Meanwhile, bring the remaining 300 ml of water to a boil. Transfer the hot water to a heatproof measuring jug or bowl, then add the bloomed gelatin mixture. Stir thoroughly until the gelatin has completely dissolved and the liquid is smooth.

If using espresso shots instead of relying entirely on instant coffee, reduce the water by 30 ml for every espresso shot added. For example, four espresso shots (120 ml total) should be paired with 180 ml of hot water.

Stir in the sugar followed by the instant coffee powder. Begin with the smaller amount of coffee, taste the mixture, and gradually increase it if a stronger coffee flavor is preferred. Continue stirring until everything is fully dissolved.

Remove any foam floating on the surface with a spoon to achieve a cleaner, clearer finish.

Carefully pour the coffee mixture into a square or rectangular mold if you plan to cut it into cubes, or divide it among individual serving cups for single portions.

Let the mixture cool to room temperature before covering it and refrigerating for approximately 4 hours, or until completely firm.

Once set, slice into bite-sized cubes if using a mold, or simply serve directly from the cups. Finish with your preferred syrup and toppings before serving.

In a small bowl, thoroughly combine the sugar with either the kanten agar powder or agar agar powder. Mixing them together first helps distribute the setting agent evenly.

Pour the water into a saucepan while it is still cold. Sprinkle the sugar and agar mixture evenly over the surface, then whisk or stir until well combined.

If incorporating freshly brewed espresso, reduce the water by 30 ml for each espresso shot used. For example, four espresso shots (120 ml) require only 380 ml of water in the saucepan.

Place the saucepan over medium heat and slowly bring the mixture to a boil. Once boiling, reduce the heat slightly and allow it to simmer gently for 1–5 minutes, stirring occasionally. Since cooking times vary between brands, always refer to the package directions for the most accurate timing.

Remove the saucepan from the heat and let it cool for a few minutes. Stir in the instant coffee powder or prepared espresso until fully dissolved. Mix gently to avoid incorporating excess air, which can create unwanted bubbles.

Skim away any foam that forms on the surface using a spoon.

Slowly pour the liquid into molds or serving cups, taking care not to introduce air bubbles. Allow it to cool completely at room temperature before transferring it to the refrigerator. With agar-based desserts, refrigeration is mainly for chilling, as the mixture begins setting as it cools.

Once chilled, cut into cubes if prepared in a mold, or enjoy directly from serving cups. Add your preferred syrup and finish with toppings such as whipped cream, ice cream, or chopped nuts before serving.