First All Grain

[scul]

Hi all, first post here and questions about my first All Grain brew.

I just got done brewing my first all grain (https://www.homebrewtalk.com/f70/honey-orange-hefeweizen-169857/) and I have a question about gravity changes during boil.

After taking the pre-boil gravity reading, I saw it was (what I thought) very low at 1.028 @ ~155*F (no temp correction). OG per the recipe is 1.045. I did some quick research, and saw suggestions to add about 1/4 lbs DME to bring the gravity up. After I was finished and the brew was in the carboy, I looked up more about gravity temp correction, and it looks like I was actually pretty close w/o the DME.
The kicker is, I have no idea what my OG is, as I broke my hydrometer trying to take the OG.
Good news: great excuse to buy a refractometer . Any recommendations?

Is there any way to estimate my OG with the following info?

Pre-boil: 6.2 Gal wort @ 1.028 @ 155*F + 1/4 lbs Light DME
Post-boil: 4.5 Gal into the carboy.

I had a boil over at the first hop addition, so that accounts for the large loss during boil - seems like I could expect about 1 gal loss during the boil.

 

[LLBeanJ]

Pre-boil corrected for temp puts you around 1.049 + 2 pts for the DME = 1.051

(51 x 6.2)/4.5 = 70.27 = 1.070 estimated OG

Edit: That 1.070 figure will be a bit high due to the loss of sugars from the boilover. 1.070 is what it would have been if you boiled down to 4.5g. Given that you lost about a gallon, I guestimate that you lost about 16% (1/6.2) of your sugars, so 70 x .84 = 59 = 1.059 give or take.

 

[scul]

Great, thank you.
Is the high gravity going to affect the final beer, other than more alcohol? Might it finish above the desired fg?

Should I boil some water, cool it, and add it to the carboy to compensate? How much water? It's in a 6.5 gal carboy, so lots of room.
Or just leave it alone?

 

[LLBeanJ]

If it were me and I was that much over expected OG, I'd probably go ahead and add some top off water, but there's no harm in letting it go as-is. FG will likely be a few points higher than expected, assuming the same attenuation.

Edit: adding 1/2g top off would lower the OG by 6 pts.

 

[scul]

Thanks, I'll probably go ahead and add that extra top-off. More beer is always good, right