44% efficiency??

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jrodder

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So this is a head scratcher. I haven't brewed in a year, but this is really crazy even for maybe being rusty. I realize I screwed up on using a 6 gallon for the batch and not 5.5, and end of boil volume was 7.3 and not 7 as it should have been.

14lbs - pale 2-row
12oz - crystal 40
8oz. - carapils
2oz. - acid malt

batch size - 6 gallons
boil size - 8.32 (ended up with 8.5)

estimated OG 1.06

I use a 70 quart cooler for the tun, keggle for boil and sparge water heating.

I measured gravity after the single batch sparge, I swear it read 1.040 at 110 degrees. I adjusted for temperature and it said that's 1.046, so really only .002 off of what beersmith said my preboil should be. (1.048)

So not bad I'm thinking. I boil down, end up around between 7.25 and 7.5 in the kettle. pull off a cooled sample and measure gravity... it's 1.044! How in the heck is that even possible? I went ahead and boiled up some DME to add in and fix it, but I must be missing something major. I did BIAB and hit numbers every time. I also crushed my own grains for the first time, crush looked good as far as I can tell. No feeler gauges handy, I went with a '2' gap on a Millars Mill 2 rollers.

Is this a math fail?
 
Pre-boil SG measurement is the likely culprit. You dumped low gravity wort into high gravity wort. Unless you mixed the wort very aggressively, it was probably stratified. You then took a sample from a higher gravity strata. After the boil, the wort is thoroughly homogenized, so it is likely more representative of reality.

Brew on :mug:
 
If you had ~7.5 in the kettle and it measured 1.044, that's pretty close to 60% efficiency. Not unheard of, but not great.

Unfortunately I have had mixed luck with temperature converted hydrometer readings. Sometimes they seem to track well, but other times they are all over the map. My rule of thumb is that the chilled sample going into the fermenter is the only number I know is accurate, so if the other readings don't agree, they were somehow wrong.

With a new mill it would be a good idea to keep an eye on your mash gravity to make sure that conversion isn't taking longer than you thought. If you measure the gravity vs the strike water volume you can get the "conversion efficiency." I have seen bad crushes give me ~85% conversion, good crushes give me closer to 97%, and that type of swing could change my brew-house from a typical 75% down to the 60% you saw.
 
If you had ~7.5 in the kettle and it measured 1.044, that's pretty close to 60% efficiency. Not unheard of, but not great.

Unfortunately I have had mixed luck with temperature converted hydrometer readings. Sometimes they seem to track well, but other times they are all over the map. My rule of thumb is that the chilled sample going into the fermenter is the only number I know is accurate, so if the other readings don't agree, they were somehow wrong.

With a new mill it would be a good idea to keep an eye on your mash gravity to make sure that conversion isn't taking longer than you thought. If you measure the gravity vs the strike water volume you can get the "conversion efficiency." I have seen bad crushes give me ~85% conversion, good crushes give me closer to 97%, and that type of swing could change my brew-house from a typical 75% down to the 60% you saw.

For information on using mash thickness and mash SG to determine conversion efficiency look here.

Brew on :mug:
 
Pre-boil SG measurement is the likely culprit. You dumped low gravity wort into high gravity wort. Unless you mixed the wort very aggressively, it was probably stratified. You then took a sample from a higher gravity strata. After the boil, the wort is thoroughly homogenized, so it is likely more representative of reality.

Brew on :mug:

I pulled that sample after dumping all the sparge water in. I didn't do a first drain before sparge because I am a cheap bastard still, and I move he keggle from the high position to low after full water volume is in the tun. I figured that would be a valid sample. I wouldn't call it a 'vigorous' stir, but I mixed really well to get the sugars moving.
 
If you had ~7.5 in the kettle and it measured 1.044, that's pretty close to 60% efficiency. Not unheard of, but not great.

Unfortunately I have had mixed luck with temperature converted hydrometer readings. Sometimes they seem to track well, but other times they are all over the map. My rule of thumb is that the chilled sample going into the fermenter is the only number I know is accurate, so if the other readings don't agree, they were somehow wrong.

With a new mill it would be a good idea to keep an eye on your mash gravity to make sure that conversion isn't taking longer than you thought. If you measure the gravity vs the strike water volume you can get the "conversion efficiency." I have seen bad crushes give me ~85% conversion, good crushes give me closer to 97%, and that type of swing could change my brew-house from a typical 75% down to the 60% you saw.

Stupid question, but how does one actually do the calc to determine the conversion efficiency? I'm guessing it's online, maybe I should just go Google. :)
 
Stupid question, but how does one actually do the calc to determine the conversion efficiency? I'm guessing it's online, maybe I should just go Google. :)

Follow the link in post #4. If you don't understand how to do the calc after reading that, then ask again.

Brew on :mug:
 
I pulled that sample after dumping all the sparge water in. I didn't do a first drain before sparge because I am a cheap bastard still, and I move he keggle from the high position to low after full water volume is in the tun. I figured that would be a valid sample. I wouldn't call it a 'vigorous' stir, but I mixed really well to get the sugars moving.

If you didn't drain the MLT prior to adding the "sparge" water, you didn't actually sparge. You just diluted the mash in the MLT, which gives the same result as a no-sparge process, but with additional work (for no benefit.) I don't see what being a "cheap bastard" has to do with not draining the mash before adding "sparge" water.

Many (most) people underestimate what is required for good mixing (i.e. achieving zero concentration gradients.) I still believe your pre-boil SG measurement was in error due to stratification in the wort.

Brew on :mug:
 
Follow the link in post #4. If you don't understand how to do the calc after reading that, then ask again.

Brew on :mug:

Read it, understood it, then cheated. BrewersFriend calculator says:

Gravity at 100% Efficiency:
1.112 - max
Gravity at 75% Efficiency:
1.084
* Efficiency:
41.07%
Points / Pound / Gallon (ppg):
15.1

using my grain bill and the 5.5 gallons I mashed in with. I also used 1.046 as the gravity reading, but maybe that was just wrong. I will try next with a finer crush and a longer mash. The temps were pretty spot on, mashed at 155.
 
If you didn't drain the MLT prior to adding the "sparge" water, you didn't actually sparge. You just diluted the mash in the MLT, which gives the same result as a no-sparge process, but with additional work (for no benefit.) I don't see what being a "cheap bastard" has to do with not draining the mash before adding "sparge" water.

Many (most) people underestimate what is required for good mixing (i.e. achieving zero concentration gradients.) I still believe your pre-boil SG measurement was in error due to stratification in the wort.

Brew on :mug:

Cheap bastard meaning I only have one kettle. I have to drain into something. I do have a spare pot that has a 4 gallon capacity, but I didn't want to mess with having to drain into two separate pots. Didn't see any issue with just doing a batch sparge without draining? Unless that's an issue... Duly noted though, I'll find something to drain into next time and see if I can avoid stratification issues.
 
Unfortunately I have had mixed luck with temperature converted hydrometer readings. Sometimes they seem to track well, but other times they are all over the map.

^This. I've never had an accurate SG measurement from a wort sample over 100 degrees. If I take the sample at 110F, measure, convert, then chill to 60F, the converted number is always way off.
 
Read it, understood it, then cheated. BrewersFriend calculator says:

Gravity at 100% Efficiency:
1.112 - max
Gravity at 75% Efficiency:
1.084
* Efficiency:
41.07%
Points / Pound / Gallon (ppg):
15.1

using my grain bill and the 5.5 gallons I mashed in with. I also used 1.046 as the gravity reading, but maybe that was just wrong. I will try next with a finer crush and a longer mash. The temps were pretty spot on, mashed at 155.

I don't believe you input the correct volume to the BF efficiency calculator. Given your process, you need to use the total volume of water added before you drained your MLT.

Brew on :mug:
 
I don't believe you input the correct volume to the BF efficiency calculator. Given your process, you need to use the total volume of water added before you drained your MLT.

Brew on :mug:

Gotcha, since I did measure the entire volume and not first runnings. Sorry, it's been a long day. So nowhere near as bad as I thought, which I knew considering 44% would be actually HARD to achieve. :) Thanks for the advice, gentlemen! Next time finer crush and longer mash and see where end up.
 
Cheap bastard meaning I only have one kettle. I have to drain into something. I do have a spare pot that has a 4 gallon capacity, but I didn't want to mess with having to drain into two separate pots. Didn't see any issue with just doing a batch sparge without draining? Unless that's an issue... Duly noted though, I'll find something to drain into next time and see if I can avoid stratification issues.

All you need is a spare 5 gallon bucket to either collect the first wort in or temporarily hold the sparge water as you drain the first wort to the keggle.

Adding water before draining first wort is not sparging unless you are doing a fly/continuous sparge. A batch sparge requires fully draining the tun, adding the batch sparge, stirring and draining again.
 
What doug293cz said......this happened to me once.....drove me nuts after I meaured preboil SG.....until I stirred it and then remeasured and got what I was supposed to have....

Trust your final measurement you should be good!
 
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