First all grain batch with very high OG..

[namuch]

I just did my first all grain batch. A very simple 2.5 gallon SMaSH (5 Lbs Vienna, NB hops, and Nottingham ale yeast). I used a BIAB no Sparge technique that I read in another thread, and all went well through the process until just before pitching when I took my original gravity reading. It came out to 1.062!

According to ibrewmaster, it shoulda been about 1.048 at 80% efficiency. To my calculations, i got 103% efficiency. How did that happen? I was running about 3.75 gallons during the mash, and started the boil with about 3.25 gallons. Boil ended dead on with 2.5 gallons, which was right with the rest of my recipe scaling.

I've been doing partial mashes and extract batches for several years now, I've never been this far off, ever... Any ideas?

 

[stevehardt]

Was the wort well mixed?

Did you correct for temp?

 

[chickypad]

Was the wort well mixed?

Did you correct for temp?

Check these, but I also think your calculations are off. According to several sources Vienna has potential of 36 ppg so 5 lbs in 2.5 gal should give you about 1.057-1.058 at 80%. You seem to be about 86% if those measurements are on.

 

[namuch]

Check these, but I also think your calculations are off. According to several sources Vienna has potential of 36 ppg so 5 lbs in 2.5 gal should give you about 1.057-1.058 at 80%. You seem to be about 86% if those measurements are on.

Interesting. I was going by the stock numbers for Vienna that is built into ibrewmaster. I will have to check that and send them a report if it is that far off. Thanks for the reply, that makes me feel quite a bit better about it.

 

[WoodlandBrew]

Agreed, your calculated potential sugar is high. You should hit about 80% brew house efficiency with 100% conversion of 5 lbs of grain in 3.75 gallons of mash water and no sparge, so you are doing something right.

(5lbs of grain displaces about 0.4 gallons, meaning 3.35 gallons of water are in the mash, and absorbs 0.6 leaving 2.75 gallons of run off. 2.75/3.35= 82%)

For details see here:
http://woodlandbrew.blogspot.com/2012/12/when-more-grain-doesnt-add-more-sugar.html

 

[namuch]

Ibrewmaster shows vienna malt at 1.036 SG. Is that the same as 36 ppg? Or, should i be looking at something else?

 

[chickypad]

Ibrewmaster shows vienna malt at 1.036 SG. Is that the same as 36 ppg? Or, should i be looking at something else?

Yes, that's what I had too. So 1lb in 1 gallon at 100% efficiency would give you 1.036.