picture by peter macrobert from a recent bbq; can you spot the ice-cube? barely? good!
Use good ice. The best way to get good ice for a G&T at home is:
1) buy a brita filter and use it to fill a rinsed-out kettle
2) boil the water before bed and let it cool overnight
3) repeat, next morning, if you can be arsed
4) pour water into tupperware container to a depth of ~40mm, cover with lid and freeze hard into a single paving-slab-like brick
5) put the ice onto a padded cloth; using a blunt, straight object (eg: the back of a heavy carving knife or cleaver), shear a rectangular block of ice about 40x40xWhatever and clean that up into one single, nice 40mm-cubed ice cube.
Use this for the G&T.
Why? The Brita removes chorine and the boiling removes other dissolved gases, the resulting ice is bright and clearer as a result.
The single big cube has a large ice volume but a relatively smaller surface area than several cubes, so melts (dilutes the drink) more slowly.
If you boil the water in a saucepan you can get clearer ice / even fewer bubbles, which makes for an even clearer, slower-melting cube; it takes longer but yields better results.
The problem with bubbles is that they expose large amounts of surface area without much ice-mass behind it, so again melt quickly.
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This has me thinking outlandish thoughts, mostly involving speculation on how Heston Blumenthal might prefer to make ice.
Simple method: distil the water.
Theatrical method: Burn Hydrogen in pure Oxygen, collect the condensate.
The question then begged, is how to do the freezing bit. Freezing the water at different pressures a la P W Bridgman wouldn’t help – you want to yank the latent heat into your ice at zero degrees C, not more – but I wonder whether the rate of freezing would have an effect?
I believe the rate-of-freezing issue is mostly relevant to trapped gases; if there are no gasses dissolved in the water then no problem.
Unless seriously treated, water from a borehole will likely contain a lot of dissolved solids. Depending on the geology of the area, it might be choc-full of calcium carbonate (hard water).
This will make for a more flawed ice crystal which will have a lower enthalpy of fusion and will take less energy to break water molecules from the crystal lattice.
In theory, slower cooling will result in bigger ice crystals and more heat will be required to break it back into a liquid. However, crystal formation is heavily influenced by impurities – more impurities will provide greater numbers of crystal seeds and more crystals. Hard water should freeze quicker.
Very pure (and still) water doesn’t freeze very well – it needs a seed to form around, even if that is just converging pressure waves; see youtube for supercooled water (e.g., http://www.youtube.com/watch?v=DpiUZI_3o8s).
Does this mean that I have better ice because all my water comes, untreated, from a well about 110 feet down?
I missed the obvious; I reckon Heston would use dry ice :-). I’ve made some cocktails chilled with dry ice, back in Uni days (Chemistry labs sometimes have technicians who appreciate a lark) and they worked (sometimes too) well. Probably insufficiently civilised for a G&T, though.
Also, while not pertinent to a G&T, I remember PJ O’Rourke writing that “it’s the salt in the olive that gives a Martini its snap”. Some drinks *might* work with ice that’s slightly saline, so you get your drink super-chilled without having to put the bottle back in. the freezer regularly…
Certainly with a martini the aim would be to get just the right amount of the saltiness in there while mixing the drink. For that purpose I’m thinking normal sized ice cubes made from the brine left in the bottom of a jar of olives might work.
As for the production of large ice cubes, is there any reason not to make them in silicone cake moulds? Easier than hacking a large lump of ice into pieces.
I like making one big block chiefly because it obviates finding several large moulds.
My fridge makes BIG ice cubes using a filter. Not crystal clear, but large.
The real trick is actually making sure the ice is really cold. If the ice is slippery, it means that it is close to 0c, if it sticks to your fingers, it’s a few degrees below. Never use slippery ice in drinks, it’ll water them down amazingly quickly. I keep my freezer at -14 degrees. My ice stays ice for at least 30 minutes, while wet ice from an ice bucket typically only lasts about 5. Finally, it helps to keep the gin in the freezer and the tonic in the fridge, so there is less work for the ice to do.
Finally, I don’t disagree with the aesthetic benefits of clear ice, but I want to cool my drink as quickly as possible, I just don’t want my ice to melt. Gassy or clear ice will release the same amount of water, gassy will do it quicker. The BIG difference is the ice’s starting temperature.
(As a native Caribbean person who cannot drink a drink without ice in it, you can probably tell I have thought a lot about this over the years.
My friends say I have an ice fixation. I have been known to bring my own ice with me to parties, just in case the host has forgotten to stock up, or offers me those crappy little freezer bag based ones.)
More: http://www.ginjourney.co.uk/oddments/in-search-of-the-perfect-ice-cube/