Dave Arnold, the food world’s very own mad scientist, has a book out – Liquid Intelligence – The Art and Science of the Perfect Cocktail. This isn’t a book for the faint-hearted – it’s not a simple book of recipes. Sure, there are recipes in there, but there’s much, much more to it than that. In the book, he describes all the equipment a bar person might need: everything from a simple spoon to a rotary evaporator. He describes all the techniques you need, from clarification to carbonation. And most importantly, he tells you exactly what is going on in your drinks – the science of making a cocktail.
If you ever want to see what a real-world mad scientist looks like in action, then you should watch him making a simple Gin and Juice.
But this book is not just about the science, there’s art there too. Each drink is carefully crafted so that not only do the flavours balance perfectly, but the drinks looks beautiful too. His Gin and Juice is a perfect example – whilst most bartenders simply strain their grapefruit juice to remove the bits, Dave Arnold clarifies his so that it is crystal clear. In his bar, he uses a centrifuge to do this, but his book includes instructions on how you can achieve the same result at home without any fancy equipment. I just had to try this.
I started with four grapefruits and juiced them. Even ignoring the bits of pulp that ended in there, this stuff was pretty opaque.
So, first step was to add some agar, and then I left it to set to a very soft gel. Once set, I froze the juice in the freezer until it was solid, and then took it out and left it to defrost slowly in the fridge. This bit takes forever. The next day, I checked in on my juice and it was still a solid block, no sign of any melting whatsoever. It wasn’t until the day after that that I started to see liquid come off, and the whole thing took about two and a half days in total. But it was well worth the wait, this stuff was beautifully clear.
And it tasted just like grapefruit juice. Clarifying hadn’t destroyed any of the flavour at all – if anything, it improved it slightly by removing a touch of that harsh bitterness that you sometimes get with grapefruit.
Next, mix with gin (Tanqueray, of course) and a little water, and add a pinch of salt. The final step is carbonation, so I poured the mixture into my iSi whipping syphon and then placed the whole thing into the freezer to chill for a couple of hours.
Later that evening, we were ready to try the drink. I took the whipper out of the freezer and gave it a good shake – it was full of cold icy slush now. I carbonated it with three cartridges, giving it a good shake and then fully venting between each one, leaving it to stand fully charged for a minute or so each time. Finally, I poured it into chilled glasses.
The carbonation was spot on – the bubbles raced up through the perfectly clear drink – it looked for all the world like a glass of champagne. And it tasted absolutely marvellous. The grapefruit flavour and gin go together so well, I think I’ve just found myself a new favourite drink.
This cocktail may have taken three days to make, but it was worth every second. I still have half the juice left, so I will be making another one very soon now, and I think it’s probably time to start juicing some more grapefruits.
If you’re at all interesting in making cocktails, I can’t recommend Liquid Intelligence enough. It’s very well written, highly informative, and beautifully presented. Add a copy to your Christmas wish list today.