A.k.a. a “measurant”
This is not about how the metric system is a superior system of units (although it is). It is about exactly one thing: the inadequacy of jigger when scaling recipes and converting between units.
First about the scaling. I like smaller drinks. I will always take 2 smaller drinkers over 1 bigger drink, so I can taste more things! But I also make a lot of drinks for others, and I want them to be able to track their alcohol intake. This means it’s about the total amount of alcohol per drink, and the percentage ABV is irrelevant. If I make a “low ABV” cocktail, but the volume is large, then the total amount of alcohol could still count as a single drink. Now if this person is, for example, by car and they know they want to drink let’s say 1 drink, they need to know that it’s not secretly 2 drinks worth!
I find it useful to keep some numbers in mind, so let’s introduce a table of various alcoholic drinks with their volume and ABV and then index them to a “normal drink”. You can look at the wikipedia page for “standard drink” to see how different countries define their standard “unit of alcohol”. 10 grams (or 12.7 ml) of pure alcohol is the most common, while the UK uses 8 gr (10 ml), and in the US everything is bigger so it’s 14 gr (17.7 ml).
Something quite unhelpful in this is that when people (or the government) say that the body can break down about 1 unit or 1 drink per hour, or that you can still drink and drive with a max of 2 drinks, this refers specifically to the UK unit (according to wikipedia), which is the smallest unit.
Rather than use the UK unit as the standard drink, and start to tell people that “actually, did you know that a standard drink is smaller than you think, so you should multiple that number of drinks in your head by 1.75”, I will index to the amount that people typically call 1 drink in normal everyday usage. For me the most standard drink is a decent beer like a blonde or IPA that comes in a 330 ml bottle and has a 6% ABV. This is almost 20 ml of pure alcohol, which is also what is in a 50 ml shot of 40% ABV spirits. So this will be my main reference point for the drinks I make.
| Drink | Volume (ml) | ABV | ml pure alcohol | UK units | Standard units | US units | Colloquial units |
| Small beer | 250 | 5 | 12.5 | 1.25 | 0.98 | 0.71 | 0.625 |
| US standard beer | 360 | 5 | 18.0 | 1.80 | 1.42 | 1.02 | 0.9 |
| Craft beer (blonde/IPA) | 330 | 6 | 19.8 | 1.98 | 1.56 | 1.12 | 0.99 |
| Belgian beer | 330 | 8.5 | 28.1 | 2.81 | 2.21 | 1.58 | 1.40 |
| White wine | 150 | 12 | 18.0 | 1.80 | 1.42 | 1.02 | 0.9 |
| Red wine | 150 | 15 | 22.5 | 2.25 | 1.77 | 1.27 | 1.13 |
| Shot liquor | 50 | 40 | 20.0 | 2.00 | 1.57 | 1.13 | 1 |
| US Manhattan | 60+30 | 40, 20 | 30.0 | 3.00 | 2.36 | 1.69 | 1.5 |
| My Manhattan | 40+20 | 40, 20 | 20.0 | 2.00 | 1.57 | 1.13 | 1 |
So when I make a Manhattan, I don’t use the imperial measurements of 2 oz / 1 oz, or 60 ml of bourbon to 30 ml of vermouth. I use 40 ml as my base, so it’s that much of bourbon to 20 ml of vermouth for me. That actually is the same as a 50ml shot of spirits, instead of 1.5 shots.
Now I’m not going to calculate the exact alcohol content of every recipe. And I’m definitely not going to scale the recipes to a couple of millilitres! But if I see a recipe where the base spirit(s) amount to 60 ml, then I’m scaling everything down by ⅔ if I can
Yes, “my” 20 ml is more than any of the other “standard” units. But now my guests only have to count the number of drinks, and know that they’re all about the same amount of alcohol as a single shot or a single nice beer or single glass of wine.
Alright, now the next point is to get to that exercise of scaling and how all jiggers are inadequate!
If you measure in ounces (and let’s set the ounces equal to 30 ml for convenience, instead of 28.4), then the proportions that are available to you in your jigger are typically: 4:3:2:1. In other words, your smallest subdivision is 7.5 ml and all ingredient amounts are typically integer amounts of that.
But when I take a recipe in ounces and I want to convert it down by the aforementioned ⅔, then my smallest subdivision is 5 ml. And as most of us know, 5 ml is not found in most jiggers. Jiggers in the ml scale have subdivisions of 10, and they go up to 40 or 50 ml. So even though in principle the same proportions are available to you (4:3:2:1), they are only available if you scale up instead of down.
So let’s just convert every gradation in ounces to ml and also scale it down by 2/3.
| Ounces in original recipe | Scaled down by ⅔ to ml |
| 2 oz | 40 ml |
| 1.5 oz | 30 ml |
| 1 oz | 20 ml |
| 0.75 oz | 15 ml |
| 0.5 oz | 10 ml |
| 0.25 oz | 5 ml |
You’ll see that the 5 and 15 ml levels are very relevant levels, but these are not available for jiggers that measure per 10 ml. I did find a jigger that has 2 ml gradations, but those are too close to easily tell apart, and that jigger is also ugly and not nice to work with. I have a super cute mini-pyrex with a tiny handle and a tiny pour spout that has 5 ml gradations, but you have to hold it up to eye level (because it’s on the outside of the glass), the markings are on the wrong side when I hold the jigger with with my left hand, and it always spills a little when I pour…
Let’s also look at some typical ratio’s and if they make reasonable drinks with one or the other drink. 2:1 drinks obviously are fine in both scales. However, a 3:2:1 drink in ounces would be 45+30+15 ml which is just about the right size, assuming the 45 is base spirit, and the 30 and 15 are something like vermouth or 20-ish % liqueurs. With only 10 ml increments, you’d either have to make 30+20+10, which is too small, or double it, which is way too much! On the reverse, a 4:2:1 drink works better in ml, because 40+20+10 is reasonable, but 30+15+7.5 is really small, 60+30+15 is too large, and 45+22.5+11.25 doesn’t exist!
So the current solution is that I have some nice jiggers that measure in quarter ounces, next to the ones that have 10 ml gradation. I actually prefer the ounce based one when making my own recipes most of the time. Then for each drink I’ll choose the appropriate scaling. Something in 7.5-ml-base, sometimes in 10-ml-base. But I’m not going to use 2 jiggers for 1 drink, that’s where I draw the line!
Also, some of you may argue that 5 ml is about a barspoon, but this is not the case for mine. I have 2 nice barspoons, and I did plenty of measuring for this exact purpose, and both of them are about 3.5 ml (rather close ⅛ of an ounce).
Thank the gods then that I recently found my favorite jigger yet. Not quite the jigger of my dreams, but pretty close! It’s from OXO, and I’m sure many of you have one – it’s also the most used one in youtube cocktail land I’ll bet – but here in Europe they added some extra lines. I was a little sceptical before buying it, a bit suspicious that is was just a relabeling of the US version that would play a bit fast and loose with the exact values, but it’s actually better than I had hoped for!
You see, the OXO has a narrow part that’s just part of the base model, which is 7.5 ml (¼ oz) on one side and 10 ml (⅓ oz) on the other, but they added an actual 5 ml mark line with laser etching! Halleluja!
Now one side has 5, 7.5, 15 and 30 ml (the 7.5 is not marked with a label though), and the other has 10, 20 and 50 ml. I measured the markings carefully and they’re all correct. I was assuming that the mark at 20 would secretly be 22.5 ml (¾ oz), but it really seems to be 20.
So I ordered 2.
This still is not my dream jigger. For that I’m still missing the proper 22.5 and a 40. If I could make my own, I would make it in quarter ounce increments up to 30 on one side, and in 5 ml increments up to 40 on the other. Does that not give me 15 and 30 on each side? Yes it does. Sweet sweet redundancy.