Q: Anthony, any thoughts on using a single piece of craft ice in place of cubed ice for shaking? I've heard that shaking with craft ice provides a better (finer/silkier) texture for sours as it creates fewer ice shards that break up the egg proteins in the drink.
A: I haven't done any controlled research on shaking with craft ice, though my experience tells me it would defeat the point of choosing shaking over other chilling methods (e.g., stirring). The three main reasons to choose shaking are:
2. Creation of ice chips; and
3. Faster chilling.
All three of the above outcomes are improved with cubed ice versus one large piece of craft ice. Aeration is dependent on the number of solid bodies breaking the liquid surface tension to introduce air, so clearly many smaller cubes would be more effective than a single large cube (smaller bodies are also more effective at aeration than larger bodies, so this would be a corollary advantage for cubed ice). Creation of ice chips increases with increased surface area exposed to impact so here again cubed ice would come out ahead, and chilling speed (both convective and conductive, the two methods that are active during shaking) is also tied to surface area -- the greater surface area of many smaller cubes chills faster than the smaller surface area of one larger cube.
This being the case, it seems that a single large piece of craft ice would be a poor choice to use for shaking: the advantages of craft ice (smaller surface area, decreased melting/dilution) are directly in opposition to the goals that shaking is trying to achieve. Using craft ice may make more sense for stirring, in which the bartender is trying to minimize aeration and ice chips, but chilling would be slowed. Regarding drink texture, aeration is what creates the silky texture we all love in drinks that include egg or other proteins -- the bartender is essentially beating the eggs. The best way to eliminate ice shards is to double-strain the drink not decrease the efficiency of aeration, which would just require that the bartender shake the drink longer to achieve the same consistency.
It's probably best to remember the original intention of large pieces of craft ice, namely, to hold pre-chilled liquids at temperature. Once a drink has been cooled to service temperature, a single large piece of ice is quite capable of keeping it at that temperature with a minimum of additional dilution. However, craft ice is usually an ineffective tool for initially bringing a drink to service temperature.