Equal Parts Cocktail Measurement?
Generally speaking, cocktails are measured by volume not weight.
Jiggers, cups, and other tools you use to measure out ingredients for a cocktail.
Your options here are simple and few, so this is not terribly complicated.
Jiggers are the basic hourglass-shaped stainless-steel measuring device you've seen in many a bar. These are cheap and easy to find in most housewares stores, or online. Typically, the larger cup measures out exactly one jigger, or 1 1/2 ounces. The smaller cup is normally one half jigger, or 3/4 ounces. Be careful, a number of other sizes exist, and you should know what units you're working in.
Many professional bartenders have built up strong proficiency with using these in settings where speed is of an essence. The way to use a jigger most efficiently is to hold it between thumb and forefinger, or between your first thumb and forefinger, or between your first and second fingers, like so:
Hold the jigger steady, and fill it brim-full with your liquid of choice; and then it's easy to quickly tip the contents into a shaker or mixing glass.
Another type of jigger is similar to the hourglass model, but it's mounted on a rod.
Really, though, it's rare that a home bartender needs to worry about speed. A professional bartender in a high-capacity bar needs to work lightning fast, obviously, but for the home schlub mixing a pre-dinner daiquiri, it's just not necessary.
At home, I almost never use a jigger, unless I just want to practice my jiggering. First of all, not all jiggers are equal: some that might appear to measure a true jigger actually measure 1 1/4 ounces instead of 1 1/2. (The model with the handle, in the picture at top, is one such miscreant.) If I want accuracy in my measuring (and I do), I don't want to have to second-guess the capacity of my tools. My measurer of choice is the Oxo mini angled measuring cup.
I love this darned thing and I use it daily. I even preferred it during my stint as a pro bartender. I only have one problem with it: there's no mark for 3/4 ounces. I usually eyeball it, or if I need more precision, I measure 1/2 and then 1/4 ounces.
I should note, too, that some bartenders don't like measuring amounts as small as 1/4 ounce in these cups. To explain why, I need to mention something called a meniscus. It's the curve in the upper surface of a liquid that's in a container. The reason some people see this as a problem is that the curve can make it difficult to accurately read how close you are to the 1/4-oz. mark.
I have to say I'm not convinced it's always a problem. At most we're looking at a couple of drops of liquid's difference between an accurate measure and an inaccurate measure. If you're measuring a strongly flavored ingredient, such as absinthe or Fernet Branca, a couple of extra drops could affect a cocktail. But for milder tasting ingredients such as lemon juice or simple syrup, it's not going to make a huge difference. - Cocktail 101: Measuring Utensils
Jiggers are used for accurate measurements and are the foundation of consistent cocktails.
A cocktail jigger is a shot or cocktail measuring cup for bartenders, ranging in sizes of 0.5-2.5 oz. For ease of use, many jiggers have fill lines on the inside or outside with oft-used cocktail or shot glass measurements.
The word jigger can also be used as a unit of measurement in cocktail recipes. If you happen to come across a recipe that calls for a jigger (or jigger shot) of any spirit, that refers to the standard jigger size of 1.5 oz. Shot glasses come in various sizes, but a standard shot glass is also 1.5 oz. So in some instances, a jigger and a shot can refer to the same thing. A smaller 1 oz shot, or the 1 oz side of the jigger, is referred to as a “pony shot.”
Common Jigger Sizes
Generally, these bar measures come in a variety of sizes, including: