Well, faced with the question of how to capture the smell of chicken stock, which normally escapes into the air, we devised this contraption. Its basically a very rudimentary distiller. Because we already had an old fashioned pressure cooker which was easily adapted, it cost the price of a piece of tubing bought from a home-brew shop. and it works. By attaching the tubing to the air outlet of the pressure cooker we curled the tube up in a tub, and filled the tub with iced water. Vapor coming off the stock condenses once it hits the cooled tubing and liquid drips out the end. The liquid is transparent, it looks like water, but the smell... to say it smells of chicken is an understatement, a couple of drops of the good-stuff will make anything become like essence of chicken.
By switching the collection bottle throughout the length of the process, we were able to seperate different levels of distillate. This is a really simple way of collecting this surprisingly strong, essence of chicken.
For those without the means to access a Rotary, or (supercool) Rocket Evaporator, this is a great way to get into flavour collection in the kitchen. The same setup can also be used to steam distill, the best way of extracting aromatic compounds from plant material. By putting a steam basket into the pressure cooker, hot water underneath and choopped herbs, flowers, or anything else for that matter on top, the vapour which leaves will have the smell of whatever you put into the pot. By doing this you will collect both tiny quantities of essential oil and lots more the aqueous part, known as a hydrosol (for example rosewater) which can be used to explore the fantastic world of aroma.
Once the best smells have come off from the stock, the stock can be reduced, and as it cools, and the gelatin begins to set, some of this essence can be added back into it. The gelatin helps capture the aroma, but make sure you don't do it when the stock is too hot, because these molecules are extremely volatile and so evaporate very easily. and make sure you keep a lid on it, otherwise your rich aroma will disappear into thin air.