Efficiency 96% too good to be true... first AG batch

[gatomalo]

First AG batch over the weekend, an Oktoberfest Ale (very similar I've discovered to BierMuncher's). I was more focused on staying on top the process as a whole and making sure my equipment was working properly more so than focusing on the finer details.

I got around to calculating my efficiency today using brewersfriend calculator, and they've got me at 96%

My pre and post boil wort gravity were around 1.060... actually 1.057 and 1.061. I was expecting a lot closer to 1.050. For my AG, I wouldn't have been surprised with 1.045. I'm pretty meticulous about the volume of water I use and the temp at which I take my readings, but this was surprising.

I'm certain that this is not correct - but I'm not sure at which point along the way.

I batch sparged for 60mins, using a CPVC manifold in my rectangular cooler, and then boiled for 90mins.

Thoughts?

 

[atoughram]

Unlikely but maybe?

What was the recipe?

 

[myndflyte]

How were your pre and post boil gravity readings the same? Especially after a 90 min boil?

 

[mdbrewer1]

First AG batch over the weekend, an Oktoberfest Ale (very similar I've discovered to BierMuncher's). I was more focused on staying on top the process as a whole and making sure my equipment was working properly more so than focusing on the finer details.

I got around to calculating my efficiency today using brewersfriend calculator, and they've got me at 96%

My pre and post boil wort gravity were around 1.060... actually 1.057 and 1.061. I was expecting a lot closer to 1.050. For my AG, I wouldn't have been surprised with 1.045. I'm pretty meticulous about the volume of water I use and the temp at which I take my readings, but this was surprising.

I'm certain that this is not correct - but I'm not sure at which point along the way.

I batch sparged for 60mins, using a CPVC manifold in my rectangular cooler, and then boiled for 90mins.

Thoughts?

Did you do a temperature correction on those readings? As myndflyte mentioned, those don't seem right for a 90 minute boil.

 

[myndflyte]

Or did you take a gravity reading from your first runnings instead of after you were done sparging?

 

[gatomalo]

How were your pre and post boil gravity readings the same? Especially after a 90 min boil?

I didn't understand it at the time, and was more worried about getting my boil started. But I didn't put much faith into the reading. I figure my post poil OG reading was more worthwhile. I probably should have dumped and taken a new reading.

How much of a difference should I have seen between the two readings?

Clarification - 96% was my pre-boil efficiency. 81% brewhouse efficiency. I sitll think that's really high for my first rodeo.

 

[gatomalo]

Did you do a temperature correction on those readings? As myndflyte mentioned, those don't seem right for a 90 minute boil.

No temp correction. Reading was done once it cooled to 60deg (it was a cold day in TX last Friday...)

 

[myndflyte]

I brewed an all grain recipe this past weekend and my preboil gravity was 1.045 and my post boil OG was 1.056 and I lost a little more than a gallon during the 60 min boil.

 

[gatomalo]

Or did you take a gravity reading from your first runnings instead of after you were done sparging?

I'm not sure I understand the difference?

My sample was taken from my kettle once I reached pre-boil volume... about 6.6 gallons.

 

[j1n]

Why do you think you didnt get 96%? Its not impossible to get that. when i first started i was getting upper 80s to low 90s.

 

[LovesIPA]

My pre and post boil wort gravity were around 1.060... actually 1.057 and 1.061.

This is the clincher for me. When you took your pre-boil wort sample, the wort in the kettle was stratified. Denser liquid was at the bottom (near the ball valve) and the less dense liquid was at the top.

I once had the same thing happen to me, but my efficiency, which was already typically in the 90% range, was over 100. I knew it wasn't possible but wasn't sure exactly what I did wrong.

Next time stir your kettle well before taking the sample.

Your post-boil sample is much more accurate because the boil mixes the wort up very well.

 

[myndflyte]

I'm not sure I understand the difference?

My sample was taken from my kettle once I reached pre-boil volume... about 6.6 gallons.

What I meant was after your mash, you run the water off. This wort is going to have a much higher gravity than the water you run off after sparging. If you collected the wort from just the mash, that would throw your numbers off.

But the fact you got it from the kettle means you did it after sparging, but there still must be some error because there is no way it only increases 0.003 points in gravity after boiling.

 

[myndflyte]

Why do you think you didnt get 96%? Its not impossible to get that. when i first started i was getting upper 80s to low 90s.

That's not impossible, but it's impossible to not change in gravity after a 90 min boil, unless he condensed the liquid back into the kettle.

 

[Roundhouse]

What was your grain bill? How many gallons did you get into the kettle? How much was in the kettle after the boil. Tell us those numbers and we can tell what your efficiency was.

 

[gatomalo]

Why do you think you didnt get 96%? Its not impossible to get that. when i first started i was getting upper 80s to low 90s.

I'm under the presumption that my pre-boil gravity is off. After a brief lesson on the various efficiency, I further don't think it's possible to have the same gravity pre- and post-boil. Boiling off water should result in a higher density volume.

 

[gatomalo]

What was your grain bill?

Avangard Pilsnen 4.25 lb
Avangard Vienna 2.5 lb
Munich 20L 2.0 lb
Caramel/Crystal 20L 1.0 lb
Aromatic Malt 1.0 lb
Carapils 0.5 lb

How many gallons did you get into the kettle?

6.7 Gallons (not 6.6 as stated earlier)

How much was in the kettle after the boil

5.5 gallons

 

[j1n]

Why does that matter?

I just take a gravity reading after the boil and use the volume of wort in the fermentor to figure out the brew house efficiency.

 

[gatomalo]

BrewToad has my calculated/predicted OG at 1.055... in my brews, I'm usually 1pt or two below.

I bought the grains for this recipe from the LHBS - they mill and bundled it all up for me. I didn't think to weigh it out, but I wonder if they goofed and I ended up with more grain.

Assuming I mashed according to my recipe, is it possible to end up with a higher than predicted OG?

 

[LovesIPA]

BrewToad has my calculated/predicted OG at 1.055... in my brews, I'm usually 1pt or two below.

I bought the grains for this recipe from the LHBS - they mill and bundled it all up for me. I didn't think to weigh it out, but I wonder if they goofed and I ended up with more grain.

Assuming I mashed according to my recipe, is it possible to end up with a higher than predicted OG?

I told you what probably happened in post #11.

 

[gatomalo]

Well that might make sense pre-boil but my post-boil OG was higher than predicted.

Is this a calculation error or a matter of process?

 

[ncbrewer]

Check out this section in Braukaiser: http://braukaiser.com/wiki/index.php?title=Batch_Sparging_Analysis
From his graph it looks like the maximum lauter efficiency for 10 lbs of grain and single sparge would be about 87%. If I'm reading this right, there must be something wrong - I think your question about grain weight makes sense.

 

[gatomalo]

by the way, i don't assume i did everything correctly here on brew day.

in fact, i had the wort chiller hose pop off as i inadvertently plugged the outlet switching between buckets. small splash of hose water went into the wort. a whole heck of a lot ended up on the patio floor as i scrambled to turn off the hose.

i'm going to review that sparge analysis tonight. all i know is that my brew started percolating quite nicely within 12 hrs of brewing - a success in my book - and my OG was "in the range".

 

[HaDaL]

If We assume that your measured pbg (post boil gravity) and measured volumes are correct so based on your recipe and your post boil volume,your EE% should be around 74% not 96% .Also beer calculators predict the OG based on some assumptions such as common EE% or typical yield % of malts thus depending on how efficient your system is and what extract potential your malts have, You may achieve lower or higher numbers.

 

[gatomalo]

If We assume that your measured pbg (post boil gravity) and measured volumes are correct so based on your recipe and your post boil volume,your EE% should be around 74% not 96%.

So how do you get to 74%?

I'm assuming PBG is correct. Volumes were measure/calculated using volume of cylinder (dimensions of my pot and height of wort on my mash paddle). I think those are safe assumptions.

 

[HaDaL]

I used ProMash app to calculate your EE%.This is it's report:

A ProMash Recipe Report
.
.
.
Recipe Specifics
----------------

Batch Size (Gal): 5.00 Wort Size (Gal): 5.50
Total Grain (Lbs): 11.25
Anticipated OG: 1.060 Plato: 14.81
Anticipated SRM: 11.7
Anticipated IBU: 0.0
Brewhouse Efficiency: 74 %
Wort Boil Time: 90 Minutes

Pre-Boil Amounts
----------------

Evaporation Rate: 14.00 Percent Per Hour
Pre-Boil Wort Size: 6.96 Gal
Pre-Boil Gravity: 1.043 SG 10.79 Plato

Formulas Used
-------------

Brewhouse Efficiency and Predicted Gravity based on Method #1, Potential Used.
Final Gravity Calculation Based on Points.
Hard Value of Sucrose applied. Value for recipe: 46.2100 ppppg
% Yield Type used in Gravity Prediction: Fine Grind Dry Basis.

Color Formula Used: Morey
Hop IBU Formula Used: Tinseth
Tinseth Concentration Factor: 1.30


Grain/Extract/Sugar

% Amount Name Origin Potential SRM
-----------------------------------------------------------------------------
37.8 4.25 lbs. Pilsener Germany 82.23 2
22.2 2.50 lbs. Vienna Malt Germany 80.07 3
17.8 2.00 lbs. Munich Malt(dark) America 71.41 20
8.9 1.00 lbs. Crystal 20L America 75.74 20
8.9 1.00 lbs. Aromatic Malt Belgium 77.91 25
4.4 0.50 lbs. Cara-Pils Dextrine Malt 71.41 2

Potential represented as % Yield, Fine Grind Dry Basis.

 

[LovesIPA]

Well that might make sense pre-boil but my post-boil OG was higher than predicted.

Is this a calculation error or a matter of process?

It could be both. Any error in any measurement, whether it's grain weight or volume of water in the HLT, is going to affect the efficiency.

 

[GreatLakesBrewer]

First AG batch over the weekend, an Oktoberfest Ale (very similar I've discovered to BierMuncher's). I was more focused on staying on top the process as a whole and making sure my equipment was working properly more so than focusing on the finer details.

I got around to calculating my efficiency today using brewersfriend calculator, and they've got me at 96%

My pre and post boil wort gravity were around 1.060... actually 1.057 and 1.061. I was expecting a lot closer to 1.050. For my AG, I wouldn't have been surprised with 1.045. I'm pretty meticulous about the volume of water I use and the temp at which I take my readings, but this was surprising.

I'm certain that this is not correct - but I'm not sure at which point along the way.

I batch sparged for 60mins, using a CPVC manifold in my rectangular cooler, and then boiled for 90mins.

Thoughts?

You can actually back into your pre boil efficiency if your sure that your readings for volume pre and post boil are correct. I'm going to assume that your pre-boil reading was inaccurate because you said you didn't correct at all for temp.

Post Boil OG: 1.061 @ 5.5 Gal.

Drop the O.G. format and stick with 61. So 61*5.5=335.5 (Total Gravity Points in your Pot). Since gravity points don't evaporate during the boil all you have to do is divide 335.5 by your pre boil volume to calculate O.G.

335.5/6.7=50, put that back into format and your at 1.050 for pre boil OG. Before you question yourself I would check to see if your hydrometer is in working order, I had to have mine replaced awhile back because of a slight crack.

 

[Yooper]

I didn't understand it at the time, and was more worried about getting my boil started. But I didn't put much faith into the reading. I figure my post poil OG reading was more worthwhile. I probably should have dumped and taken a new reading.

How much of a difference should I have seen between the two readings?

Clarification - 96% was my pre-boil efficiency. 81% brewhouse efficiency. I sitll think that's really high for my first rodeo.

I'm not sure I understand the difference?

My sample was taken from my kettle once I reached pre-boil volume... about 6.6 gallons.

It's not possible to have a 96% preboil efficiency, and an 81% brewhouse efficiency, with the same readings. Your reading will change and so will your volume. The reading is suspect. Maybe the preboil wort wasn't stirred or mixed well for the preboil reading?