OG : Before or After Boil

[Kayos]

I'm little embarrassed to ask....as an extract brewer I always did an OG after boiling as I transferred into primary. Now that I am AG.....I realize the boil-off would make a huge difference in the OG.....so....do I take it just after I get the wort from my MLT or as I transfer like I used to?

 

[Yooper]

I take it before and after- I use Beersmith software and it can calculate your preboil efficiency when you do it before the boil. But your "real" og is taken just before you pitch the yeast.

 

[Orfy]

You should take your gravity readings out of the mash tun before boil then after the boil.

You can then work out your mash conversion efficiency (The important one)
along with your over all effieciency.

 

[ajf]

If you take the gravity before the boil, you can work out if you need to make any adjustments during the boil. If you wait till after the boil, it's too late to make any gravity boosting adjustments. If you need to calculate the ABV (or ABW), you will need to take the gravity at pitching time.
It's also useful to take the gravity of the runnings as you sparge. This can indicate when to stop sparging, and also indicate the effectiveness of your sparging techniques.
On the other hand, you can also completely forget about the hydrometer, or just use it to determine when fermentation is complete.

-a.