Found this for future reference:
Cooking With Alcohol
When cooking with beer or alcohol,
does all of the alcohol evaporate?
No.
The following chart should be helpful.
Alcohol Retained
No heat application, immediate consumption 100%
No heat application, overnight storage 70%
Alcohol ingredient added to boiling liquid, and removed from heat 85%
Flamed 75%
Baked, approximately 25 minutes, alcohol ingredient on surface of mixture (not stirred in) 45%
Baked/simmered, alcohol ingredient stirred into mixture
15 minutes 40%
30 minutes 35%
1 hour 25%
1.5 hours 20%
2 hours 10%
2.5 hours 5%
source:
Minnesota Nutrition Council Newsletter