OG way off!!

So I just brewed NB's Number 8 Belgian Strong Ale from AG. The OG should have been 1084 but it turned out to be 1060.

I trying to figure out what went wrong. I was using a digital thermometer so I'm fairly sure the temp for my mash was spot on, 149 degrees. Maybe I sparged to quickly?

I'm stumped.

I didn't use a pH balance additive. Maybe that was the problem?

 

I've been using a digital thermometer for about a year; I finally checked it against a lab thermometer and found it reads about 5* low, meanain I've been mashing high all this time. But that will affect attenuation and FG more than OG.

Other ideas: Did you stir the mash really, really well? Did you wait 90 minutes?

Did you check the gravity of your runoff? Maybe you needed to run off more pre-boil wort, and boil longer.

Did you boill off too much, top off with water, then check the gravity? This is a common way of getting an incorrect reading.

 

I waited 60 min. And I did not check the gravity of the run off.

My end boil was just where I wanted it. 5 gallons.

 

Mash pH? I've fallen victim to that.