Brewing AG Now - Pre-Boil Gravity 13 Below Target?

[Jiffster]

The estimated gravity is 1.040 and my pre-boil gravity is 1.027. I'm ramping up to boil temp now.

Will I boil until OG hits target or just let it be? (Rather not add DME this time)

What did I do wrong in the first place?

My first running SG was 1.071 (Collected 2 gallons)
Sparge SG was 1.015 (Collected 6 gallons)

 

[Qhrumphf]

What's your preboil and post boil volumes?

 

[Jiffster]

Pre oil volume is 7.5 gal. Post should be 5.5

 

[Qhrumphf]

At 5.5 gals you should hit about 1.037 based on a preboil of 1.027 at 7.5 gals. For some that maybe close enough to not bother, but if you want your 1.040 you could either bump up with DME, or add whatever time you need to your boil to go to down to 5 gals (5.06 is what I calculate to hit 1.040). I would add that time before hopping (based on your boiloff I'd say 15-20 mins if you're losing 2 gallons in an hour boil), and then just hop as normal, rather than adding it at the end.

 

[beerfactory]

when checking the preboil gravity, does the wort need to be cooled to room temperature? I am asking because I took an inaccurate preboil gravity reading this weekend.

 

[Jiffster]

when checking the preboil gravity, does the wort need to be cooled to room temperature? I am asking because I took an inaccurate preboil gravity reading this weekend.

I used a temp correcting refractometer.

 

[Stillraining]

Pre oil volume is 7.5 gal. Post should be 5.5

That seem like a gallon to much PB to me.

 

[Jiffster]

At 5.5 gals you should hit about 1.037 based on a preboil of 1.027 at 7.5 gals. For some that maybe close enough to not bother, but if you want your 1.040 you could either bump up with DME, or add whatever time you need to your boil to go to down to 5 gals (5.06 is what I calculate to hit 1.040). I would add that time before hopping (based on your boiloff I'd say 15-20 mins if you're losing 2 gallons in an hour boil), and then just hop as normal, rather than adding it at the end.

I've already started hoping.

First hop was "First Wort".
Second was at 30.
One more to go at 5

 

[Yooper]

when checking the preboil gravity, does the wort need to be cooled to room temperature? I am asking because I took an inaccurate preboil gravity reading this weekend.

Yes, because any hydrometer reading taken above about 90 degrees is so inaccurate as to be worthless.

It's not such a concern with a refractometer, since a drop of wort cools pretty quickly but I still give it a few moments to cool a bit before putting it on my refractometer.

ATC doesn't really correct for wort temperature- it corrects for room temperature- but since a drop or two of wort cools so quickly it doesn't matter so much.