On fruit juice.
You’re not going to get far in cocktailworld without fruit juices and the mantra here is fresh is best. Mostly. The good news is that fresh fruit juice really isn’t very difficult. First of all 80+% of juice based cocktails use either lime juice or lemon juice. If you’re serious about cocktails you should always have at least a few lemons and limes in your fridge and there is simply no substitute for fresh lemon or lime juice. Ever. If you see a recipe that calls for sour mix (aka sweet and sour) or lime cordial then that is a bad recipe – probably left over from The Dark Ages.
Limes come in two kinds, Key and Persian. For pies you want Key, for cocktails you want Persian. If it’s tiny it’s a Key (aka Mexican) otherwise it almost certainly a Persian. Furthermore, Persian limes (I’m just gonna call them “limes” now if that’s OK with you) come in quite a variety of colours, sizes and textures. If you’re after juice, the best limes are fairly round, smoother skinned and can be a little on the yellow side of green. Expect about 1 ounce/30ml of juice per lime. People expect their limes to be a dark green but limes are actually only ripe when they start to yellow. If you’re paying per lime then get the biggest ones you can but if you’re paying by weight (which is usually in warmer climes where they are cheaper anyway) size doesn’t really matter. The heavier the lime the more juice in it. For garnishing you can use the dark green knobbly skinned limes but don’t expect to get very much juice out of them. Limes can be expensive little buggers so I buy them by the bag at the market as they keep pretty well and don’t take up much fridge space. If you keep your limes in the fridge they’ll stay fresh for weeks and as an added bonus you get a little bit more juice out of a cold lime. Lime juice can be squeezed in advance of a shift/party but loses flavour after a few days. Keep the juice in a marked glass or chef’s plastic sauce bottle and clean well between uses. Small bottles (200-350ml) are better as you tend to pour lime juice in small quantities.
The best way to juice your limes is a Mexican elbow hand juicer. This looks like an oversized garlic press and are easily available from any decent kitchenware shop. They generally come in green, yellow or orange corresponding to the kind of fruit they squeeze best. So which colour do you want for limes? No, you want the yellow one. No, really, you do. The yellow one works best for both lemons and limes. You can also use a rotary juicer but you won’t get as much of the yummy oils from the skin in your juice and that would be a pity. To use a Mexican elbow cut your fruit in half along the “equator” and place cut side down in the juicer. Squeeze firmly and the fruit will be turned inside out. It’s a bit counter intuitive the first time but with practice you can juice a lime in a few seconds. Don’t try to squeeze every last drop out of the fruit as you’ll just be squeezing the bitterness out of the pith. There’s no need to strain lime juice as limes have no pips and very little pulp. Be careful to wash your hands well after squeezing limes as strong sunlight on lime-splashed skin can cause a nasty burn that takes weeks to go away. I found that one out the hard way.
I know you’re thinking “here we go again!” but don’t worry; lemons are pretty much just lemons. Everything I said about limes applies to lemons too except that you’ll get a bit more juice per lemon (about 1.5oz/45ml). Squeeze them the same way as limes in your yellow lime squeezer but sieve out the seeds and pulp before use or bottling.
With other juices such as orange, grapefruit or pineapple you have a choice. Fresh is always best but these juices cope much better with pasteurisation than lemon or lime. Bottled juices from your health food store are usually a lot fresher tasting than carton juice from the supermarket and well worth stocking. Apple juice is occasionally called for in cocktails and this should always be the cloudy kind and preferably bottled. Many Tiki drinks call for grapefruit juice and if not stated assume this means white grapefruit juice. These seem to be becoming increasingly difficult to find in favour of sweeter red and pink ones which will totally ruin your Navy Grog. Fortunately I’ve found the best bottled white grapefruit juice fairly acceptable.