Most of us have them always handy, but is a two finger pour always a good idea?

Anecdotal evidence from members of our testing community suggests that one can get surprisingly, um… wrecked, with only a two-finger pour. As a 1-dimensional measure, how does “two-fingers” translate to volume in different containers? We borrowed some fingers to find out.

Supplies

• various containers one might drink from; we used: 32 oz. Ball jar, pint Ball jar, pint glass, collins, tumbler, small square glass, small round glass
• measuring glass(es)
  • due to the large variability in vessel size, we ended up measuring with several calibrated containers, one of which had several units available. To minimize estimation errors, volumes were initially recorded in the unit that had an integer value closest to the poured volume.
• ruler
• guest hands
• fluid of choice: apparently “two fingers of whiskey” is pretty typical, although we had store-bought “moonshine” for the photo ops and after-science. As responsible science-doers we used water for all recorded measurements.

Lots of options with lots of volumes… from left to right: 1/2 gallon Ball jar, pint Ball jar, pint glass, collins, local university-branded double-old fashioned glass, small square glass, small Hennesy-branded round glass

Procedure

We measured the “height” of the stacked middle and index fingers of four people to determine the variability of that dimension. Measures ranged from 1.375 to 1.5 inches (sorry; while metric was preferred we were lacking a suitable measuring device).

Guest-hand S, who had suggested/inspired this post, was used (two-finger measure of 1.4 inches) for all pours. The two fingers were held level against the bottom of the vessel (or above the solid glass base if that was significant), and liquid was poured until it reached the top of those fingers. For comparison, our guest hand with the thickest two finger measure was used for a couple pours to see how human variability might impact the resulting poured volume (although, according to Ask a Bartender as noted below, this was actually a “standard” finger).

Note; depending on the instruments available to measure the volume, unit conversions may be necessary. All volumes reported below are provided in US-stupid and metric, but were initially recorded in ounces, teaspoons, or centiliters.

Results

Comments:

Obviously, this result should speak for itself on the suitability of relying on “two fingers” in all situations:

a.k.a. use a proper measuring glass!

Additionally, the natural variation in human fingers can make a significant difference, even in a small glass like a collins; in a ridiculous beverage container like the 32 oz Ball jar, that can equate to a difference of an extra shot.

There has been some effort to standardize the finger pour to 3/4 inch per finger, which in an old fashioned glass should be about 1 oz per finger (Kenyon, Ask a Bartender 2010). While not specified in that article, this would presumably be a “single” old fashioned glass (6-8 oz). Serious Eats notes that the traditionally small cocktail glasses are getting hard to find, which fits our observations at local stores. In our trials with our smaller-than-standard test fingers, the glass we identified as a double old fashioned (12-14 oz) yielded just over 2 oz per finger width.

While the fact that the volume of a two finger pour varies with container isn’t surprising, the shear volume of that pour in the larger containers is a bit startling, as was the difference between hands. A finger based pour would be fine if calibrated against a known set of glassware, but use with caution, especially if ball jars are involved!

Related Sources:

Dietsch, Michael. March 17, 2011. Serious Eats, Cocktail 101: Glassware Basics . Accessed Feb 7, 2015.

Kenyon, Sean. Nov 1, 2010. Westword, Ask the bartender: Giving all those old bar terms the finger. Accessed Feb 3, 2015.