How soon would you rub and inject a brisket before actually putting it on the smoker? This is for a

[sharonabalogna]

Any help here? I'm cooking a brisket for competition , how long before putting it on the smoker would you rub and inject ? As long as possible or just before? 

 

[kam59]

I inject and the first rub layer goes on about 6 hours before going on the cooker. The second layer goes on right before it hits the cooker.