I’ve been using kid goat stock in loads of recipes to finish sauces or to add flavour to stews and soups. Basically, I’ve been using it like a stock cube and its worked really well. So when I went to college and suddenly had access to a £6000 freeze-dryer I set myself the challenge to make a kid goat stock cube.
The first step was to freeze the ingredients. I had my stock already made and frozen but to get the commercial cube look I finely diced some carrot and celery and froze that down as well. Once it was frozen I placed it on a tray and put it in the freeze-dryer for 72 hours.
Freeze-drying is also know as cryodesiccation, which probably sounds less appetising but I prefer it, and involves changing the water in the food from a solid to a gas without it passing through the liquid phase, this is called sublimation. This is achieved by reducing the pressure around it as it thaws, forcing the frozen water into a gas so the food remains dry and all the water is extracted. The result is a very light and powdery but solid and usually with a more intense flavour than the original, as it has lost 99% of the water it previously contained.
I was really excited to see what came out of the machine. The carrot and celery had changed flavour completely and had a strange chewy texture but they were recognisable once they reconstituted in the mouth. The stock had the look of frozen crystals but was powdery to the touch. I bound the components of the cube together with some vegetable fat and set it in the fridge. I didn’t have a cube mould unfortunately so its more of a stock cylinder but it stuck together well.
The next test was to see how it would reconstitute back into a liquid stock. It was made with meaty bones slowly simmered to release gelatin, which is what thickens the stock to a sticky reduction. I wanted to see if this was still possible after water was added as this would give it the edge over supermarket stock cubes, which when reconstituted and reduced, get overly salty and don’t thicken.
I treated the cube like a supermarket one and poured boiling water over and whisked. As you can see in the video it reconstituted straight back to its original brown colour. I then put it in a pan over a high heat and reduced it and was delighted it produce a perfect sticky sauce.