davidc9057 wrote:What is the correct ratio of espresso to water for a true Americano?
The correct ratio, of course, is the one that you like the best for that particular coffee. Having uttered those weasel words, however, it is possible to offer a geek's guidance on how to accomplish this.
To make the ideal americano one first prepares a delicious espresso. In doing so, the extraction yield will generally be in the neighborhood of 19% (IOW, 19% of the original dry grounds end up dissolved in the demitasse). Second, one dilutes the espresso so that the final solubles concentration is about 1.35%. This figure varies according to taste, but 1.35% is a good starting point. See the table below for americanos prepared this way using typical doses:
Note that just as with brewed coffee, the final beverage weight will be about 14x the original dry coffee grounds. Also note that in an americano it's not the ratio of espresso to water that's critical, it's the ratio of dry coffee to final beverage weight.
Bottom line is:
(1) measure your dose in grams
(2) prepare your best espresso
(3) place americano cup on scale and tare to zero
(4) add espresso shot
(5) dilute with hot water until final americano weight is 14x the dose weight
(6) stir with silver spoon
(7) taste the beverage
(8) marvel at the deliciousness, or, if not,
(9) adjust shot/dilution parameters for next time
In a pinch, stainless steel works, too.