Help with my efficiency!!

[HopHouse]

So I brewed (or attempted to brew) a stout this past weekend.

My target gravity was in the 1.070-1.077 range

I mashed with 13 pounds of pale malt for one hour at 156 F with a water to grist ratio of 1.5 quarts/pound (about 3.5 gallons) - I added about 3 liters of boiling water as well to bring the temperture up for dough in. I had trouble keeping the temperture in the right range as every 20 minutes when I came to stir, I think I let alot of heat out of the cooler (Coleman Xtreme 70 quart).

I batched sparged with 4.5 gallons of 170 F water. I heated the water to 170 F... not sure if I needed to heat that hotter so that it would bring the temp up to 170 F. I ended up with roughly 9 gallons of wort pre-boil at a gravity of 1.044.

Boiled down to 7 gallons in an hour and ended up with 5 gallons in the fermenter. Gravity was about 1.040.


I believe I need to recalibrate my kettle and fermenter as I am not positive my water volumes for mash and sparge were accurate. However BeerSmith says my mash efficiency was about 70% but my brewhouse efficiency was 40%.

What went wrong? What are some variables I could change to make to get better results next time. This was only my 2nd all-grain batch so I'm still getting used to the process and learning what to expect from my equipment but any suggestions you all could pass my way would be welcome.

Thanks!

 

[TyTanium]

Boiled down to 7 gallons in an hour and ended up with 5 gallons in the fermenter. Gravity was about 1.040.

This. Where'd the 2 gallons go?

Your mash/lauter efficiency seems fine (though too much volume)
13 pounds x 37 pts/lb/gal = 481 gravity points at 100% efficiency
9 gallons x 44gp = 396 actual gravity points
396 / 481 = 82%...just fine

But some of your measurements must be off...because if you boiled down to 7 gallons, you should be at 1.057 (=396 actual / 7 gallons = 57), not 1.040.

7 gallons at 1040 gives you 7 x 40 = 280 gravity points / 481 max = 58% efficiency. But if you only got 5 of that into the fermentor, 5 x 40 = 200 / 481 = 42%

 

[castlefreak]

I think a few small changes in your process could really help. I've only just finished my first all grain batch, but it went pretty well. I only missed my target OG by .004 and fermentation is bubbling along as expected.

1- You mentioned that you stirred every 20 minutes during the mash. From what I understand, you only have to stir at the beginning to get everything mixed well and then just put the lid on and leave it for the duration or your single-infusion mash. I use the mash calculator at www.rackers.org/calcs.shtml/ to get my strike water temperature right so it hits the target mash temp.

2- Preheat your cooler with warm water. I just use tap water turned all the way to "hot" and let it sit for 30 minutes to sort of prime the cooler.

3- Fly sparge instead of batch sparge. From everything I've read, it seems that fly sparging is far preferred over batch sparging for just the result you are looking for, it greatly increased efficiency. My first AG setup was pretty ghetto, so I took some cues from this video (especially look at how he fly sparges without a sparge arm setup):
It's not exactly the best quality video, but this guy has a very simple setup and explains what he's doing in a "all grain brewing for dummies" sort of way. It helped me quite a bit.

Hope this helps! Cheers!

 

[afr0byte]

With 13 pounds of grain, I'm going to assume that you were doing no larger than a 5 gallon batch at 75%+ efficiency (13lbs of two-row at 75% efficiency gives you 1.072 OG). Something is way off in your measurements, obviously. Did you do a temperature correction for the final gravity reading? What temperatures did you take the gravity readings at?

 

[afr0byte]

3- Fly sparge instead of batch sparge. From everything I've read, it seems that fly sparging is far preferred over batch sparging for just the result you are looking for, it greatly increased efficiency. My first AG setup was pretty ghetto, so I took some cues from this video (especially look at how he fly sparges without a sparge arm setup): http://www.youtube.com/watch?v=1CRI1veziKI
It's not exactly the best quality video, but this guy has a very simple setup and explains what he's doing in a "all grain brewing for dummies" sort of way. It helped me quite a bit.

Hope this helps! Cheers!

I get 80% efficiency with batch sparging. Theoretically, yes, fly sparging will do a bit better, but at our scale it's not that big of a deal.

 

[tre9er]

I don't understand how your gravity went down after the boil... You should be boiling off water and making a more dense liquid.

 

[TopherM]

Sounds like you had 7 gallons post boil, but then just added 5 gallons to your fermentor, and dumped 2 gallons? There's your efficiency problem. You sparged with about 2 gallons too much water and watered down your beer.

Your TOTAL water volume should have been closer to a tad over 7 gallons, maybe 7.2-7.4 (off the top of my head). So if you mashed with 3.5 gallons, you would expect to sparge with anoth 3.7-3.9ish gallons INCLUDING the extra 3 quarts you added to the mash (you would just subtract that 3 quarts from your sparge step).

That would put you at your total water volume of 7.2-7.4ish pre-boil, and with a 1.0 gallon boiloff, small loss to trub, small loss to cooling evaperation (enter these into the beersmith default if they are not populated), you would end up with your 5.0ish fermenting volume.

Hope that makes sense.

 

[tre9er]

Still don't understand how preboil and postboil gravity were inverse of what you'd expect. How does one lose gravity during a boil? Perhaps water was added to the boil? Perhaps the "preboil" gravity was actually first-wort gravity?

 

[HopHouse]

Thanks for your responses so far.

I believe the culprit is in my water volumes...Thanks Topher.


I did boil from 9 down to 7 and only put 5 gallons into the fermenter and tossed the other 2. Should have read Designing Great Beers chapter that discusses how to handle this as I think my options were to keep boiling or add DME?

I'm not sure how my sparge volumes got so far off.

Beersmith said to add 23 quarts for mash and then 3.57 gallons for sparge. Maybe I mismeasured or need to check my calibrations for my measuring stick.

 

[afr0byte]

Beersmith said to add 23 liters for mash and then 3.57 gallons for sparge. Maybe I mismeasured or need to check my calibrations for my measuring stick.

If we assume that you'd lose about .125 gallons per pound of grain (a pretty commonly seen number) then you'd lose about 1.6 gallons of water to your grain. So, assuming you didn't lose any other water to your mash tun, that gives you just under 4.5 gallons in the boiler. So, you should have had about 8.07 gallons in the boiler, preboil. Something is definitely wrong with your measurements.

 

[TyTanium]

I did boil from 9 down to 7 and only put 5 gallons into the fermenter and tossed the other 2. Should have read Designing Great Beers chapter that discusses how to handle this as I think my options were to keep boiling or add DME?

I'm not sure how my sparge volumes got so far off.

Yup, that's exactly your problem. You're right - you could've kept boiling to get down to 5g, but that's a heck of a lot of boiling. Adding DME woulda worked too, but that stuff is expensive.

Here's a little trick for batch sparging: Plug for your sparge volume. Subtract your first runnings volume (when you drain after the mash, say 3.5g) from your pre-boil target volume (say 6.5g). So 6.5 - 3.5 and boom, sparge with 3 gallons. The majority of absorption occurs during the mash; the grain is already saturated with liquid during sparge, so you won't lose much of your sparge volume to absorption. I typically do a quart or two extra just in case.

 

[wolfman_48442]

It looks to me like you just forgot to give the wort a good stir before you took your gravity reading. The sugary wort will sink to the bottom pretty fast, and if you don't give it a good stir, you can indeed get a reading that's 20 points lower than reality. As you've seen
All in all, not a big deal. It's sure not going to ruin anything.

 

[TopherM]

The BeerSmith numbers are definitely off, but that would be a result of one of the user-defined numbers being off. A few thinks to check:

1) Are you sure you entered that this is a FIVE gallon batch? If you entered SIX or more into the batch size, it would explain these numbers.

2) On the BeerSmith recipe, under EQUIPMENT, what number do you have entered for boil-off rate? If this number was around 2+, that would explain the BeerSmith #s as well. Boil-off rate is directly related to the diameter of your pot, so everyone's boil off is unique to your equipment, but on average, that number should be somewhere in the 0.7-1.25 gallons range.

Under the equipment profile, also double check all of the other volume loss rates, like grain absorbsion (mine is about 0.7), trub loss (mine is about 0.4), loss to cooling evaperation (mine is about 0.2). Missing a decimal place in any of these number could cause your issue as well.

There is definitely an incorrect variable entered somewhere in the chain, you just need to find it and make sure you don't make the same mistake again.

 

[HopHouse]

So I looked back over my equipment profile that I set-up for my equipment. I did have the recipe set for 5 gallons.

After my first batch on this set-up I had to adjust my boil-off rate. I'm using a blichmann burner and it boiled off 2 gallons my first batch. And it did the same my second batch as well... so I had adjusted that in my profile to account for the boil off.

Equipment profile looks like this:

Boil off Rate is set at 2 gallons
Evap Rate: 27.8% per hour
Cooling Shrinkage 4%
Cooling Loss: .21 gallons

Two things I realize now that I did not do: First, I did not stir the wort before taking gravity reading pre-boil.

Secondly, I really think that my volume measurements were the problem. I need to recheck my calibration dipsticks and make sure I measured correctly because I followed the mash and sparge volumes that BeerSmith calculated to give me 7.46 gallons pre-boil... which if i boiled off 2 gallons like my system does that would have given me roughly 5.5 gallons into the fermenter which is what I wanted.

Currently my efficiency setting is set to 72% in BeerSmith, but I haven't hit that yet but I also know my first two batches haven't allowed me to accurately gauge what I can expect my consistent efficiency to be. Still working kinks out...

Anybody got anything else for me?

 

[HopHouse]

Looking over my notes in BeerSmith for this brew, I just realized I also never accounted for the 4 liters (extra gallon) of boiling water I added to bring up the mash temperature prior to doughing in.

 

[tre9er]

2 gallons per hour seeMs high to me

 

[HopHouse]

Would you recommend I turn the heat down and try to get into the 1 gallon per hour boil range?

I have a 15 gallon polarware pot... it's short and wide ... not sure if that aides in the current boiling off rate I'm getting or not.

I can reduce the heat though...

 

[afr0byte]

Yes. You'll need to baby the boil with a pot that big and a batch size of 5-6 gallons. However, you still want to make sure it's a rolling boil...not just a simmer.

 

[tre9er]

My point was I'd be surprised if you actually boil off two gallons per hour. Most kettles boil one gallon, some less

 

[TyTanium]

...I really think that my volume measurements were the problem. I need to recheck my calibration dipsticks...

Currently my efficiency setting is set to 72% in BeerSmith..

Right on. You can't diagnose anything if you don't know what you're looking at. Be precise in your volume measurements; it makes a difference.

I'd leave it at 72% for now...you should have no problem getting close to that, and you can adjust your boil time accordingly to hit your numbers.