Crystallizing is one of the best ways to capture essence and conserve the freshly cut flavours in all type of edible flowers and herbs. Commonly used to preserve rose petals and violets, however it is a technique that can be applied to aromatic herbs like Rosemary, Thyme or Tarragon.
The proteins in the egg white bind to the ester molecules in the herb, now esters are organic molecules responsible for scent and overall identity of the herb or fruit, the sugar coating the protein captures all the essential oils that manage to make it through the protein film. Dehydrating the whole lot removes all the water and we all know that water only dilutes flavours, therefore in crystallization you would be not only conserving the flavour but unlike Jam making for example it would also be intensifying the scents and the overall character of the herb.
All ingredients used have to be extremely fresh, preferably not more than a couple of hours after the plant is cut off its mother stem.
It is no use preserving fruits, flowers or herbs that are old, or of low quality with a questionable past, to preserve an ingredient is to transform it into something that would have never existed without the cooks intervention, it is given the possibility to be transcended in time , eaten when not in season in the most natural of ways.
A couple of weeks ago I was quite fortunate to find a bush of Rosemary growing in the wild just off the coast, and it was in bloom with beautiful powder blue flowers. Foraged a few stems just before returning home, and about three hours later I crystallised the lot, I can use this fragrant herb for desserts for the coming months without losing any of the scent that the plant had whilst still uncut.
I am sharing the technique with you today, it does not have to be Rosemary, try it out on whatever ingredient you like the scent of and want to keep and safeguard for later use in your kitchen.
200ml pasteurized egg whites
400g white castor sugar.
Switch on the oven at 190 degrees about half an hour before you start the recipe.
Wash the stems and dry them patiently with a clean cotton towel.
With a painting brush, paint a thin film of egg white on the leaves, Rosemary is a bit tricky because of the leaves are pine like, be patient or else opt for another herb like Thyme which is less time consuming.
Dip the egg washed stem in sugar, tipping off ant access sugar, you want a thin coat of sugar not more.
Now switch off the oven, a leave the oven door open for about four minutes, this will lower the temperature from 190 degrees to about 150 degrees, you can use a thermometer to do so, I currently have to admit that I do not own one.
Place the stems on a baking sheet lined with baking paper and place in the warm oven, close the door, go to sleep and the next morning you will be rewarded with fragrant crystallized Rosemary.