Christmas Tipple: There's an ant in my gin!
That’s the food covered but what about ending this exhausting day with a little tipple? A lot of us certainly are doing this and Britons, in fact, have bought a record-breaking 47 million bottles of gin this year, and gin derives its flavour from juniper berries. Izzie Clarke enthusiastically volunteered to visit master distiller Will Lowe at the Cambridge Distillery to see how to make gin.
Will - This is a process whereby the flavouring is achieved by redistillation. So, instead of just filling up a vat, you fill up a still, which is a large pot if you will, fill that up with ethanol and water and then you put juniper into that pot and you boil it. On top of the pot you have this sort of swan’s neck-shaped tube where the vapour path will follow. Then forces it through a condenser which is very cold, brings that vapour back into a liquid. The liquid is predominantly juniper flavoured. All of the flavour has got into the liquid through distillation so you can call that a London Dry Gin.
Izzie - Now we’re standing here right in front of the lab at the Cambridge Distillery. It’s quite an exciting, almost mad scientist lab. We’ve got these lovely bulbous glasses. Ones filled with… those look like rose petals that are just spinning around so something tells me the usual process is not exactly what’s going on here.
Will - That’s right. We use a process called “vacuum distillation” and, very simply put, at lower atmospheric pressures you also lower the boiling points of liquids. Famously, if you were to scale Mount Everest, you’d be 8,848 metres above sea level and water there would boil at just 69 degrees celsius instead of just 100. That’s a long way to go to prove a point so we use very small vessels in which we can control the atmospheric pressure by using vacuum pumps and digital vacuum gauges.
So we can control the pressure and, therefore, boiling point, to within one thousandth of a bar of pressure. What that means is that we can find the ideal temperature and pressure for every individual botanical so, as you say we’ve got rose petals there. The normal boiling point for ethanol is 78 degrees, just a above 78.3, and if you take a rose petal and cook it at that temperature you just destroy the flavour. So, instead, what we do is bring the temperature right down by bringing the atmospheric pressure right down, giving us this beautiful fresh flavour that would be achievable using traditional methods.
Izzie - How many gins overall are you making here?
Will - 1,236 at the moment. And I know that sounds like a lot, but part of what makes us completely unique is that we are the world’s first gin tailor. So, if you wanted your own gin, this is the place you come to have that become a reality. Do you want to taste it right here?
Izzie - I mean, yes please! Now we didn’t quite have time to make a gin specifically devoted to the Naked Scientists, and I’m not quite sure I want to know what that would taste like. But Will did show me one of the most unusual gins at the distillery - anti gin...
Will - There are some species of ants that have a very definite citrusy flavour to them. Every gin has some kind of citrus quality within it. It’s what makes gin so refreshing. The idea was to try and create a gin where we don’t us any citrus whatsoever and replace the entire citrus ingredient with ants.The ant that we’re using here is Formica rufa, and it is that formica that gives its name to formic acid. Formic acid, when it was first isolated, was isolated through the distillation of ants. This is about 400 years ago so we’re not the first people to distil ants, but we’re the first people to do it with a view to making gin. What we start with is ants and ethanol, and this is what it looks like.
Izzie - Will has just brought over a really large bulbous vase with a nice tap at the bottom and lots of ants floating around inside it. These aren’t the sort of ants you’d find in your back garden, they’re a bit bigger aren’t they?
Will - This is the Redwood ant, and the way that these guys defend themselves and communicate is to spray formic acid. If you imagine the ants that you would find in your backyard and multiply it by about three or four, then that gives you an idea of the scale that we’re operating on, so what we want to do is to capture that. If you try and effectively scare these guys they’ll start biting, and not only is that painful for you and it is painful, but it also means they’re getting rid of the formic acid we want to keep.
Izzie - You sound like you’re speaking from experience with that pain?
Will - Yeah. From very itch, bitter experience, yeah. I call them happy ants. We take them in from the wild - they’re not farmed, and we collect them whilst they’re on their migratory path. Then we put them directly from forest floor straight into high strength ethanol which means an absolutely instant knockout for them. We isolate the ant and the formic acid in that way and then we bring that alcohol back up here to Cambridge for distillation.
Izzie - Right, okay. Are we going to try some now?
Will - I think that would be absolutely appropriate, yep.
Izzie - Gosh! That’s really nice and straight away I’ve got that kick on the front of my tongue. It is quite zesty and it’s really staying on the sides of my tongue?
Will - Mmm. It has this kind of tingly persistent quality.
Izzie - Yeah.
Will - I remember tasting with someone and he said it’s almost like he could feel the ants dancing on his tongue.
Izzie - Yeah, it is. It’s really ‘tingly’ is exactly the way to describe it.
Will - And the ant is really the headline here. The flavour is predominantly juniper - it’s got to be. But you can really get the structure and, on the finish, that ant quality really starts to be far more expressive.