Why do my cocktails taste different than at a bar?

Five common reasons: better bartender ice, fresh citrus that bars squeeze that day, properly chilled glassware, accurate jigger pours, and higher-proof spirits. Replicating the bar at home is largely about matching those five inputs.

Restaurant bars produce consistently better cocktails than most home setups for systemic, fixable reasons. Five inputs to match: (1) Ice. Good bars use large, dry, clear cubes from purpose-built ice machines or hand-cut from frozen blocks. Home freezer ice is small, wet, and cloudy. Get silicone large-cube molds or buy clear ice. (2) Citrus. Bars squeeze fresh that morning. Home cocktail-makers often use bottled juice or fruit that's a week old. Squeeze immediately before mixing. (3) Glassware temperature. Bartenders pre-chill every serving glass in a freezer or with ice water before pouring. A room-temperature glass adds 5 to 10 degrees of warmth to the cocktail in seconds. Pre-chill yours. (4) Measurement. Bartenders use jiggers continuously; home pours are often 30 percent over or under spec. Buy a Japanese jigger with internal etched lines, $15, problem solved. (5) Spirit proof. Bars often default to 100-proof base spirits because they hold up to dilution; home bars often have 80-proof. Try the same recipe with a 100-proof rye or bourbon and the difference is immediate. Three of these (ice, citrus, jigger) account for most of the gap.