OG very low.

[larrydcarter]

So had an issue in my brewing last night. My OG was way low. It was cold out and I brewed after the sun went down outside. Gain bill was...

10lb. 6oz Briess 2-row
1lb Munich
1lb Crystal 20L
8oz Victory

I mashed in 5.75 gals of water. My target mash temp was 153F, I hit 152F. I mashed for an hour then took a sample for an iodine test which told me no starch was present. My mash ended at 146F which is a lot of loss. In the summer I don't lose any heat at all. I added one gal boiling water which brought the temp up to 168F and began to lauter. When the wort volume in the mash tun started to get low I started sparging with 169F water until I had collected 7 gals of water. I do not have a refractometer so do not know the pre boil gravity. I boiled for 80 minutes and had an ending volume of 5 gals. My OG was only 1.060. That seems low. The other week I mash just 12lb. Briess 2-row the same way and got an OG of 1.072. Any help with this? Why was my OG so low? Any help would be greatly appreciated.

 

[beergolf]

That OG is about right for that grain bill. It puts your efficiency around 70-75%. I am just going from memory and did not plug it into my brew software.

 

[larrydcarter]

Someone changed the brewhouse efficiency to 85% on my spreadsheet I just noticed (and by someone I mean me when I was playing with numbers and forget to set it back). So I built the grain amusing 85% yield because of this when I normally only get 74ish %. This time I only got 63.59% though.

 

[stevehardt]

Check the usual suspects....crush, hydrometer or thermometer out of cal, forgetting to temp correct, etc.