Beef jerky...a couple questions

itsmce

I am tackling beef jerky for the first time. I started with a 3.5# bottom round roast, trimmed maybe a half pound of fat. There was a pretty think fat cap. My son and I mixed up Alton Brown's marinade and I hand sliced the roast into hopefully not-too-thin strips. They were closer to 1/8" than 1/4". In the marinade overnight they went. This morning I started a small fire in my LBGE and watched for about an hour and a half. It seemed to be stable at about 158. Seemed about right, so I put on the beef strips. Somehow I managed to get a triple layer rigged up. 

The temp dropped to 129. 2 hours later it has managed to get up to 133.
Question #1: Should I open things up a bit to get the temp closer to 170?
Question #2: How do you know when beef jerky is done?

buzd504

I think you're fine. 

Taste it to see if it's where you want it.  The longer you smoke it, the drier it will be and the longer it will keep.  Just take it off when it's as dry as you want it - probably about 6 hours or so.