SCIENCE OF STIRRING:

Q: Does the mixing vessel and pre-chilling the vessel matter?

A: Type of container/vessel matters. Metal containers heat up and cool down quickly, so they don’t affect the drink. Pint size glasses absorb more energy from your drink making the liquid less cold then a metal mixing vessel. A heavy japanese crystal mixing glass as pictured above absorbs the most energy from the liquid. However, pre-chilling a heavy japanese crystal glass or a pint glass will make the mixing vessel just as efficient or maybe slightly more efficient then a room temperature metal mixing vessel. 

Q: Is stirring or shaking more efficient?

A: Shaking is definitely more efficient. Shaking also gets the drink to reach an equilibrium temperature faster then stirring. It takes about 15 seconds for the liquid to plateau to the equilibrium temperature and a little over a min and a half for stirring to reach that point.

Q : Does how you stir affect temperature?

A: Yes, the size of ice will affect temperature and time it takes to chill the liquid. Experiments show that small ice will chill a drink faster and colder then medium size ice and large ice. The difference in temperature is 2-3 Degrees Celsius difference. Also, cracking a big ice into smaller cracked ice may be better then using several smaller ice. Smaller ice will have to much water trapped on the surface of the ice and dilute the drink. Cracking large ice into smaller pieces will ensure most of the surface area of the small crack ice is not wet.

Q: Does stirring longer over dilute the drink?

A: Depends on what you are comparing. If you compare stirring big ice for 80 seconds to reach -0.6 Degree Celsius and stirring small cracked ice for 50 seconds until the same temperature is reached, then the answer is no.

Q: Why chill the drink to -0.6 Degree Celsius?

A: The temperature is more realistic in real life bar situation then stirring until -5 Degree Celsius for that equilibrium/plateau temperature. 

Q: Does letting the ice sit in the mixing vessel for a minute before stirring over dilute the drink?

A: The answer surprisingly is no. Ice does not dilute that much sitting in the liquid for about a minute. Ice left in the glass for a minute prior to stirring will have the same amount of weight as the liquid that is immediately stirred once ice was thrown into the mixing vessel. This is only true if both vessels have the same amount of ice, same type of ice, same size ice, and the same amount of stirring time. 

Q: Does stirring speed affect rate of dilution?

A: Yes, faster stirring will chill a drink much faster then a slow stir. There’s a reason why japanese bartenders stir very fast. A fast stir will get the drink below 0 Degrees Celsius in 45 seconds and a slow stir takes 30 seconds longer. 

CONCLUSION:

Size of the ice, speed of the stir, and duration of stirring are important factors in stirring a cocktail. Who knew stirring can be so complicated?

More info can be found on Cocktail Science

Photo courtesy of Justin Dunn