Daly's Bartenders' Encyclopedia by Tim Daly (1903, p.114)
| 1 pony | brandy | base |
| milk — ice-cold milk | dilution | |
| 1 | egg yolk — yolk of fresh cold egg | other |
- Put the brandy in a star champagne glass and add ice-cold milk, spooning well to prevent curdling.
- Drop the yolk of a fresh cold egg into the drink without breaking it and serve.
Garnish: Whole egg yolk
Preventing curdling and preserving the yolk whole are the defining service details.