HB wrote:I've often heard a cappuccino defined as a drink of thirds; searching the Internet, you'll have no trouble finding plenty of similar "1/3 espresso, 1/3 foam, 1/3 steamed milk" definitions. The SCAA competitions were recently held in our region and of course this question came up at the judges' certification workshop. You might expect that a competition would lay down rigid measures, but I was surprised that they simply defined a cappuccino as a harmonious balance of espresso, steamed milk, and frothed milk. That leaves plenty of wiggle room for regional differences.
Indeed! I wish I'd found this post
before yesterday's NWRBC judges cert' workshop!

I'd read the judge's & competitor's rules & regs multiple times before hand so was at the same quandary of having been led to believe a cappuccino was a beverage of 1/3 ratios espresso, steam milk and foam and couldn't figure out how that was supposed to work in 5 or 6oz cappuccino cups. One place I learned this 1/3 rule was the oft' referred
Milk Frothing Guide on CG which states
The cup itself should hold 5 to 7oz and no more. Sharing the space in the cup in one-third proportions is one shot of espresso, one-third steamed milk, topped by one-third foam. The only way that ratio would work would be a double shot but seems such is not the case in SCAA reality! One-third of a six ounce cap' cup is 2oz, that ain't no single shot!
So of course I brought question up in the workshop. And this caused me some problems in the practice taste calibrations finding the espresso in the cappuccinos very lacking. This morning did some more researching and now find at least one place
Schomer referring to a cappuccino as a ratio of about 5:1, which makes more sense as presented by the SCAA competitions.
Seems what I've been making at home using a double shot is halfway between a cappuccino and ~1:1 ratio machiatto.