Can I really be getting 91.88% mash efficiency?

[IndyBlueprints]

I am using a single tier RIMS system. In my last IPA, I recirculated at 152ºF for 60 minutes, then bumped temp up to 170ºF (took about 15 minutes to reach temp), then slowly fly sparged with 170ºF water. According to BeerSmith, my target post-boil gravity was 1068. Well, once I got 7.5 gallons of wort into my boil kettle, my gravity was 1.065, pre-boil. This was measured with a refractometer, after stirring well.

I use "Primo" brand bottled water, I had the water tested at Ward Labs, and add the brewing salts recommended by John Palmers spreadsheet. My PH 15 minutes into the mash was 5.33

This is my grain bill:

13.8 # of Northwestern 2 row pale malt
0.625 # of British Amber malt.

I entered my gallons of pre-boil wort and my grain bill into the calculator on brewer's friend site: http://www.brewersfriend.com/brewhouse-efficiency/ and it came in at 91.88%

Isn't that like ridiculously high?

 

[TANSTAAFB]

Yep! That's the short answer...That link is for brewhouse efficiency which includes extract efficiency but isn't just extract. When did you last calibrate your refractometer? What was post boil gravity? What was post boil volume?

Mind sharing that Ward labs report on Primo? That would be very useful information to add to the community! My schity water suuuuucks! I happen to have 5 gallons of primo sitting in my mud room that a previous tenant left and would love to brew the same beer with the 2 and see what, if any, differences might be detected...
Back to our regularly scheduled programming 😁

 

[TANSTAAFB]

And how confident are you that your volume measurements are accurate? I went to the link and plugged in your #s and if all measurements are accurate then it looks like you got over 90% conversion or extract efficiency! I've never used that particular tool, I like that they go into the explanation of efficiency.

 

[TANSTAAFB]

Just plugged your numbers into Beersmith and it nailed your numbers! Set at 72% efficiency, 6 gallon batch it predicted your pre-boil volume at 7.5 gal and pre-boil gravity at 1063. Setting efficiency at 74% gets 1065. Not sure how the brewersfriend calculator works but I know I trust Beersmith. Dude, you've got Rims, pH meter, refractometer...Get Beersmith yesterday!

 

[IndyBlueprints]

Hhhmm. How does Brewhouse efficiency translate to Mash Efficiency?

I also had my municipal water tested both before and after my softener. It came in with Bicarbonate @ 515ppm, and Total Alkialinity @ 428ppm, so pretty much unusable.

Here is the Primo water report.

 

[TANSTAAFB]

Thank you sir, you're a gentleman and a scholar!
Brewhouse efficiency accounts for all losses into the fermenter, so you need an accurate starting gravity reading and accurate volume measurements in the fermenter. Mash efficiency is just how much of the potential sugars you extracted from the grain. You could have great conversion efficiency and have tons of losses through the process like dead space in the MLT or kettle, poor trub management or lots of hops soaking up wort, not accounting for losses of volume in pumps and hoses, etc. that result in poor brewhouse efficiency.

 

[McKnuckle]

Mash efficiency is just how much of the potential sugars you extracted from the grain.

Technically, that's conversion efficiency.

Mash efficiency is conversion efficiency times lauter efficiency, which is volume losses from mash tun to kettle. So you have the sugar extraction plus the degree to which you retain all the liquid volume you started with. Those two factors make up mash efficiency.

If you subsequently lose no additional volume after collecting wort in the kettle - other than evaporation, which doesn't count - then your brewhouse value would match your mash efficiency. You have to pour every drop from kettle to fermenter to achieve that.

 

[IndyBlueprints]

Just plugged your numbers into Beersmith and it nailed your numbers! Set at 72% efficiency, 6 gallon batch it predicted your pre-boil volume at 7.5 gal and pre-boil gravity at 1063. Setting efficiency at 74% gets 1065. Not sure how the brewersfriend calculator works but I know I trust Beersmith. Dude, you've got Rims, pH meter, refractometer...Get Beersmith yesterday!

First, I'm confident of my volume measurements, as I am using a Spike Brewing 15 gallon kettle, with marks on the inside of every 1/2 gallon.

My pre-boil volume was 7.5 gallons. That got my OG measurement at 1.065. Since it was so high, I added a little more water from my mash tun, got the volume up to about 7-7/8 Gallons, and brought my OG down to 1.055. I then boiled down to 6.25 gallons because my math told me that's how much I had to boil off to get to 1.068 post-boil. I ended up at 1.070.

I do use BeerSmith, I just haven't gotten it dialed into my system, or I'm just not using it right. Take a look at the picture below. I think I now have all the right volumes plugged in. I had to plug in 68% BH Eff. to get my 10.65 OG., which got my Est. Mash Efficiency to 80.2% Is that where I should leave it for now on? If that's the case, then why does it say Est Original gravity 1.065, but over on the right it says "Est. Pre-Boil Gravity of 1.050? Why are those different?

 

[IndyBlueprints]

Bottom line is, I'm trying to get everything dialed in, so I don't use too much grain when brewing any particular size of batch.

 

[TANSTAAFB]

Hmmm, not completely sure. Open up your mash settings and your equipment settings and CAREFULLY go through them line by line. I find that I usually overlooked something and it can get frustrating trying to figure out exactly where. Looks like you're getting close though! You won't know what else to plug in until you've done a couple of brews.

 

[MaryB]

Seems high... I ht 82% most of the time and suspect that might be on the high side...