Conversion and OG

[merse24]

I've been discussing some of my failed attempts with my local brew shop and he said my issue has probably been my conversion. I'm still a little confused on how to calculate this.

First question: If I hit my OG (or close) does this mean that I hit my expected conversion?

My most recent results:

8 lbs two row pale malt
1/2 lb medium crystal malt
1/2 lb light crystal malt
1/2 lb chocolate malt


12 qts @ 150 for the mash for 60 min (strike temp at 164) - I had to add 2 qts of hot water to maintain 150 during the last 15 minutes
16 qts at 168 for fly sparge.

Collected around 6.5 gallons for boil
Pre boil gravity was 1.030 (temperature corrected)
Post boi

Expected OG: 1.054 Measured OG: 1.048

Can somebody help me determine my conversion for this brew? Is there a range in which the difference in OG is acceptable or not?

 

[Terek]

its only as acceptable as you want it to be. 6 points is quite a bit low, especially in a lower gravity beer. What was your expected OG based on? I have beersmith set at 75% brewhouse eff. which is pretty standard. If your expected OG was based on 75% eff. than 6 points low is quite a bit. But if you are basing it off of 80% or higher, id say you were doing pretty good. I regularly hit around 78-80% but im more than happy with 75%

 

[Terek]

i plugged your grain bill into beersmith and set it to 75%. Your OG should have been 1048 at 75%. so you got 71% eff. So not that off. This is all based on if you got 5 gallons in your fermenter

 

[merse24]

My eff in beersmith is indeed set at 75%. And I had JUST under 5 gallons in the fermenter.