To ensure smooth jelly, allow the gelatin to “bloom” in the hot water for 1 or 2 minutes before stirring it. Allowing the granules to absorb the water like this them may help them dissolve more readily.
The coffee must be very hot (near boiling) when you use it. If you use cold coffee, it could result in stringy or clumpy coffee jelly. If you do start with cooled coffee, you’ll need to combine the coffee, gelatin mixture, and sugar in a small saucepan. Heat the entire mixture on your stove over high heat until it reaches a boil. [2] X Research source
If you wish to cut the coffee jelly into cubes, you’ll need to pour it into a lightly greased 8-inch by 8-inch (20-cm by 20-cm) pan.
If you plan to eat it directly from its dish, the coffee jelly might be ready in as few as 3 to 4 hours. If you want to cut the coffee jelly into cubes, you should wait at least 6 to 7 hours for it to solidify even further.
Consider garnishing the dishes of jelly with a dollop of whipped cream. If you wish to make cubes of coffee jelly, cut the sheet of firm jelly into even cubes using a warm knife. Gently invert the pan into a large serving dish to collect the cubes. Cover and store remaining coffee jelly in your refrigerator for up to 3 or 4 days.
Bring the mixture to a boil before continuing to the next step. Note that agar agar powder (also called “kanten powder”) works best, but you could use three-quarters of an agar stick if necessary. Break the stick into pieces and soak them for 20 minutes in separate water. Drain the soaking water, then use the broken pieces of agar as you would use the powder. [4] X Research source Equal amounts of unflavored powdered gelatin could be used instead of the agar agar powder, but gelatin is not vegetarian-friendly.
Continue cooking the mixture at a gentle simmer for approximately 2 minutes, or until everything dissolves. Stir the mixture occasionally to help it along.
During this time, the liquid should begin to thicken. Make sure that it does not solidify, though. Agar sets quickly, and waiting too long can make it difficult to pour.
After pouring the mixture into each dish, use a spoon to scoop away any bubbles that form on the surface.
Jelly made with agar will technically set even at room temperature, but the process will take more time. Moreover, the jelly will taste better cold.
Consider serving each portion with whipped cream or 1 to 2 Tbsp (15 to 30 ml) of half-and-half. Leftover coffee jelly should last for up to 2 days when stored in the refrigerator.
As the gelatin sits, the individual granules should begin to absorb the water. This process, known as “hydrating” or “blooming,” makes it easier to dissolve the gelatin once you add hot liquid.
Note that the coffee must be very hot when you add it; otherwise, the gelatin may not set properly. The coffee should also be quite strong to balance the sweetness of the condensed milk and mimic the taste of Vietnamese coffee.
You must use condensed milk. Do not used evaporated milk since it lacks the sweetness and thickness of condensed milk.
To make thinner cubes of coffee jelly, you could use a 7-inch by 11-inch (18-cm by 28-cm) glass dish or a 9-inch by 13-inch (23-cm by 33-cm) glass dish.
Thinner cubes will solidify quicker than thicker cubes. Wait until the jelly feels firm enough to hold between your fingers. To be on the safe side, you may wish to wait 8 hours or overnight.
Store extra coffee jelly in an airtight container kept in the refrigerator for up 3 or 4 days.
Ideally, you should use 4-inch (10-cm) molds or 1/2-cup (125-ml) molds. Brioche molds work well and give the finished jelly an appealing appearance, but any similarly sized mold would also work. If you do not wish to remove the jelly from its dish before serving it, you could use six to eight 1/2-cup (125-ml) custard dishes, instead. Do not coat the dishes with cooking spray if you choose this option.
As it stands, the gelatin should soften or “bloom. " The individual grain will absorb the moisture and will dissolve more readily once you add them to the hot coffee.
The coffee must be hot when you add it to the gelatin. Using cool coffee can result in stringy jelly. Continue stirring until the entire mixture seems like a smooth liquid. This should take approximately 2 minutes.
After filling the molds, loosely cover them with a single layer of plastic wrap.
Chilling them for 8 hours or overnight should result in very firm jellies, which will be ideal if you plan to remove them from their molds. If you wish to eat the coffee jelly directly from its dish, however, it might be firm enough to enjoy after 4 hours. Waiting longer will still produce a firmer texture, though.
If the coffee jelly sticks to the mold, quickly dip the bottom of the mold into hot water. The heat should loosen the jelly and make it easier to remove.
If desired, garnish each serving with whipped cream and chocolate shavings. This coffee jelly is best when enjoyed immediately, but you can cover and store the leftovers in your refrigerator for up to 4 days.
