Mash Efficiency Too High, Brewhouse Efficiency too Low

[BugAC]

Concerns with efficiency


I brewed sunday and my target pre-boil OG was 1.06. My resulting mash pre boil OG was 1.07. A mash efficiency of 100%. I took my sample and cooled it to 75 degrees before i measured. My hydrometer is calibrated correctly too.
So, as i wrap up the boil, cool down, rack to primary and add yeast, i take another reading. My measured OG was 1.062. Target was 1.070.
I was at a constant gentle boil the 60 minutes of boil time. I also fly sparge with water heated to 170 degrees. Oh, and i treat my water with salts to get the correct PH and water profile per style. The ph on my last batch should have been around 5.36.

Would could cause my efficiencies to be off? Could the lauter time affect it? I would say it generally takes about 25-30 minutes to collect 7.25 gallons of wort. Also, i use the fermentap sparge arm when fly sparging. The problem, is that in order to get full coverage with that thing, you have to increase the flow rate from the sparge tank. I haven't been doing this. I've simply been trying to keep the same flow rate as my mash tun to boil kettle. Should i maybe use a full 10 gallons of water rather than the 5 suggested by beersmith? I'd simply treat for 10 gallons. From what i've heard, it doesn't matter as long as you keep the same water level above your grains in the mash tun.

I've also realized i dont stir the grains in my mash tun prior to lautering. I typically add my mash water. Add about 1/2 my grains, stir in, then add the other half, and stir in. Then, i measure my temps. Stir a bit to keep out cold spots, then once i'm satisfied, let it sit for an hour or more.

Here's my water profile for those interested for my last batch.
http://www.brewersfriend.com/mash-chemistry-and-brewing-water-calculator/?id=CF3XK5X

 

[stpug]

Erroneous gravity readings and/or volumes are the problem, unless you're using top up water at some point.

If no top up water is used then there is simply no way to have a lower OG than PreBoil Gravity because the boiling concentrates the sugars.

 

[Psylocide]

Yeah... first red flag is 100% mash efficiency.

Not saying it wouldn't be possible, but probably didn't happen.

 

[BugAC]

Erroneous gravity readings and/or volumes are the problem, unless you're using top up water at some point.

If no top up water is used then there is simply no way to have a lower OG than PreBoil Gravity because the boiling concentrates the sugars.

I don't use top up water, and the readings are correct. I took them 3 or 4 times because they didn't seem right.

This is my equipment setup for 60 minute boils.

Equipment Profile: Bug's Initial Setup - 60 Minute
Batch Size: 5.50 gal

Mash Tun Volume: 10.00 gal
Mash Tun Weight: 9 lbs
Mash Tun Specific Heat: 0.30
Lauter Tun Deadspace: 0.25 gal

Boil Size: 7.25 gal
Boil Time: 60 min
Evaporation Rate: 10.3 %
Calculate Boil Size: TRUE
Kettle Top Up Water: 0.00 gal
Hop Utilization Adjustment: 100.00 %

Trub/Chiller Loss: 0.75 gal
Cooling Loss: 4.00
Top Up Water into Fermenter: 0.00 gal

 

[Hello]

I don't think lauter time affects efficiency. Next, I echo @stpug

 

[BugAC]

Yeah... first red flag is 100% mash efficiency.

Not saying it wouldn't be possible, but probably didn't happen.

I know, that was the first problem i had with it. Unless my grains i get from my homebrew shop are not the ones i ordered. But they've been pretty consistent with me in the past.

 

[30Bones]

Your gravity can't go down from pre to post boil.

 

[Biscuits]

I am a little confused because it sounds like you took a preboil gravity reading before you sparged. This might be the reason for the odd results. If you took a reading and then sparged, your points might drop as you add less concentrated sparge water to your wort.

 

[cyberbrew]

I had a similar situation last weekend. Took my pre-boil ~1.048, and my post boil reading was 1.046...oops! I'm guessing my wort wasn't stirred up enough after sparging so I had tons of sugars sitting on the bottom of the kettle when I pulled my pre-boil sample. Brew and learn! Next time I'll give it a good stir...

 

[doug293cz]

I am a little confused because it sounds like you took a preboil gravity reading before you sparged. This might be the reason for the odd results. If you took a reading and then sparged, your points might drop as you add less concentrated sparge water to your wort.

This sounds like the likely culprit. It is possible that OP got very close to 100% conversion efficiency, which is what would have been calculated based on strike water volume only and grain potential. To calculate mash efficiency, OP would need volume and SG to the BK compared to grain potential.

Brew on

 

[BugAC]

I am a little confused because it sounds like you took a preboil gravity reading before you sparged. This might be the reason for the odd results. If you took a reading and then sparged, your points might drop as you add less concentrated sparge water to your wort.

No, i took the reading after sparging once i collected all my wort in the brew kettle. I took a sample and added it to a test jar and cooled the jar down to 80 before taking a reading.

 

[BugAC]

I had a similar situation last weekend. Took my pre-boil ~1.048, and my post boil reading was 1.046...oops! I'm guessing my wort wasn't stirred up enough after sparging so I had tons of sugars sitting on the bottom of the kettle when I pulled my pre-boil sample. Brew and learn! Next I'm I'll give it a good stir...

I think this is it. I did not stir before taking a reading. Dammit. Well now i know. Thanks guys. I'm fairly confident this was the culprit.

 

[Biscuits]

No, i took the reading after sparging once i collected all my wort in the brew kettle. I took a sample and added it to a test jar and cooled the jar down to 80 before taking a reading.

Oh, okay, must have been the way I read it. In that case, I am clueless. I can't see how it is possible that you took a gravity reading of your wort pre-boil, and it was higher than post-boil, considering you did not top off with water. I'd venture to say that it is impossible for that to happen. I don't know what the culprit of this crazyness is, but I am thinking it might have just been a faulty reading.

 

[BowAholic]

and the good news is your target SG was 1.060 and you actually ended up with 1.062... not bad!

 

[BugAC]

and the good news is your target SG was 1.060 and you actually ended up with 1.062... not bad!

Yeah. I feel much better now that i know what happened.

Through this minor issue, and the reading up i did as i faux panicked, i have figured out ways to slightly improve my efficiency, and ways to improve my setups in beersmith. So overall, a positive. Thanks for the help guys!

 

[Gibberoni]

Yeah... first red flag is 100% mash efficiency.

Not saying it wouldn't be possible, but probably didn't happen.

I agree. I only know of 1 brewery who aims for 100% efficiency. They grind their grains down to a fine powder, then run it though a hydrolic press to achieve this. Last I was there, they were still only getting 98.5-99% eff.

Now, there are some calculator out there that consider you hitting 100% mash efficiency if you hit 100% of the 65% eff that its expecting (from what you enter in). I think brewersfriend does this.


As others have stated, there is NO WAY to go down in gravity from preboil to post boil. You have to be taking the readings wrong. Next time you brew, can you post a picture of your hydrometer reading, with a thermometer in it? This is how I take my readings. Any greater than +-2*F and I put it thought an adjustment calculator. All of my hydrometers have been calibrated to 60*F. Never seen one at 75?

[edit] wow, you all post too quick, haha. I had this typed out 2 hours ago at work and never hit post. I noticed it and hit post and its all been answered...[/edit]