The secret to a shimmering, wobbling moulded jelly is knowing your gelatine, writes Lisa Featherby.
Spring is the perfect time for jelly desserts, and with the imminent arrival of UK jellymongers Bompas & Parr for the Melbourne Food & Wine Festival (check out their elaborate creations online) and the increasing appearance of jellies on restaurant menus, we've been inspired.
The technique of making a really great jelly is worth having in your canon of cooking tricks. Almost any fruit can be transformed into a jelly by cooking it with a sugar syrup, infusing, straining and sometimes puréeing it, then setting it with gelatine (like the raspberry jelly here). Alternatively, you can take a ready-made liquid - we used Champagne - and turn it into a jelly.
Once you have your liquid for setting, the ratio of gelatine to liquid is roughly one titanium-strength leaf to 250ml of liquid for a medium set. This applies if the liquid is of pouring consistency; liquids of different viscosity will give different results. Thicker mixtures require less gelatine, while mixtures containing a lot of acid or alcohol will require more gelatine.
The gelatine debate can seem a little bewildering. The gelatine most commonly found in supermarkets is powdered, but we don't recommend using it because its flavour is strong and more evident in the final product. AtGTwe prefer leaf gelatine, available from specialty food shops and delicatessens. It comes in several strengths (silver, gold and titanium) but we use titanium-strength in all our recipes for consistency.
You might think companies producing gelatine would make each grade of leaf or powder to the same weight or setting ability, but this is not the case - the bloom (setting ability) varies between manufacturers. Stephanie Alexander has tested the strengths of various leaves, and in the latest edition of her bookThe Cook's Companion, she says she found that while one titanium-strength leaf set one cup of liquid, it took three gold-strength leaves to do the same. The best advice is to use the strength of gelatine recommended in a recipe, but if you can only get your hands on a different strength, the packet should provide instructions on how much liquid each leaf or teaspoon of powdered gelatine will set.
The trick when using leaf gelatine is to first soak the leaf in cold water to hydrate it (if you use warm or hot water it will melt), so that when the leaf is added to your hot liquid, it will dissolve straight away. Be sure to squeeze the excess water out, so you're not diluting the jelly mixture.
The type of mould you use will make your jelly more or less decorative, but when using a fluted or patterned mould it's a good idea to up the gelatine quantity slightly so the jelly will be easier to turn out. You can also create layers of flavour by setting each layer separately - we've set the raspberries at the base of our Champagne jelly using this technique.
To release a jelly from its mould, quickly dip the mould into very hot or simmering water - just enough to release the sides. Gently pull the jelly away from the sides of the mould with your fingertips - this breaks the vacuum and makes it easier to turn out. Then place a plate over the top and invert the jelly onto the plate.
The final "wobble" is the sign of a good jelly, so if yours is a little on the firm side, let it stand at room temperature for a few minutes to soften.