A cocktail may be excellent and the proportions of one ingredient to another perfect, but the recipe may suck. What measures are chosen in a recipe to express the proportions used will impact not only how easily and faithfully that recipe can be followed, but also the potential success of that cocktail.

This is complicated by some using the metric system, some fluid ounces and others 'parts'. And further confused by different-sized standard spirit measures around the world. A request for a "shot" of whiskey in a bar in the UK, USA and Germany will produce three different measures of liquid.



A UK bartender used to working with 25ml as the standard legal measure is likely to work in fractions of that measure. E.g. half a measure = 12.5ml. Meanwhile, the American used to working in ounces is likely to consider half a measure as 1/2oz / 15ml.

At least when ounces are converted to ml they are easy to comprehend but the aforementioned standard 25ml UK spirit measure is five-sixths of an ounce and half that measure is an unfathomable two-fifths of an ounce - so from an American perspective, neither 12.5ml or 25ml are particularly user-friendly measures.



Even during America's unfortunate experiment with Prohibition, the "American bar" had a dominant effect on cocktail culture to the degree that even bartenders in countries that use the metric system often prefer to use ounces in their cocktail recipes. And even many metric bartenders default to millimetre measures that equate to ounces or parts of an ounce. E.g. 30ml = 1oz, 22.5ml = ¾oz, 15ml = ½oz and 7.5ml = ¼oz.

To produce a cocktail recipe that has the best chance being faithfully replicated in bars all around the world, the measures expressed in that recipe should be universal. Obviously, equal parts are perfect for all - that's one reason why the Negroni has done so well.

However, when fine-tuning the optimum proportion of one ingredient to another while also achieving the perfect fill level in the appropriate glass (wash-line), working in quarter or third-of-an-ounce units is sometimes too restrictive.

The continued influence of American ounces has helped bring some standardisation to the units of volume which cocktails comprise, at least the most popular recipes but there is a trend in Europe for recipes to be expressed to the nearest 5ml, something that would seem to offer the necessary degree of accuracy whilst also presenting a recipe that's easy to follow (at least in millilitres). The 'sweet spot measures' are those 5ml increments which neatly convert from millilitres to ounces, as either whole ounces or commonly used fractions of an ounce. i.e. 10ml = 1/3oz, 15ml = ½oz, 20ml = 2/3oz, 30ml = 1oz.



I'm sent recipes in ml and ounces with measured volumes (other than dashes) often as small as 1.25ml (1/24 oz or quarter a teaspoon). Over the years of following and writing recipes I dreamt of having an accurate jigger with graduations in millilitres and ounces that started from 1.25ml / 1/24oz and ran all the way through the popular volumes to 60ml and 2oz. After a eureka moment with a plastic funnel, I told my friends at Bonzer about my idea and they produced what we call the Easy Jigger.

Follows a conversion table with those measures I consider 'sweet spot measures' marked in green. Those in amber are also easy to follow in either millilitres or ounces, while those in red are more problematic, unless of course, you have an Easy Jigger.



I should add that a 1 US fluid ounce is actually equal to 29.5735296ml but for simplicity, we round up to 1oz = 30ml.

When replicating cocktail recipes on Difford's Guide we try to cater for all measures with conversions from oz to ml to cl and "shots" - simply click on your preferred scale below each recipe.