What did we do wrong?? 1.094 OG, actual 1.050 OG

[btsbrewing]

Where did we go wrong? This weekend my brother and tested out our new 3 tiered gravity brew setup with brewing a high gravity imperial stout. The recipe was suppose to be a 1.093 OG, but we only hit 1.050 @ 78 degrees. It is a 10 gallon all grain recipe.

We have been brewing for the last 3-4 years so are pretty dialed in with our process. I use Beerformulator.com to create out recipes and followed the Mash and Sparge instructions as usual. We steeped out grain for 60 minutes, and then fly sparged into our keggle until we reached 11 gallons in the brew keggle and continued with brewing. I was extremely shocked to find our OG to be only 1.050, our efficiency is usually around the 75% range.

Two things came to mind about what might of gone wrong, at the brew store that we always shop at, we used their grinder, perhaps the grain wasn't ground correctly? Or perhaps with high gravity beers we should of mashed for a longer period of time?

Can anyone shed some light on where we might of messed up? Thank you fellow homebrewers!

Forgot to add the grain bill:

Pale 2-row - 25lbs
Roasted Barley - 4lbs
Crystal 80L - 2lbs
Flaked Oats - 2lbs
Chocolate Malt - 2lbs
Black Patent - 1lbs

View attachment Stout_allgrain.pdf

 

[max384]

It sounds like you're more experienced than me, but I'll throw out ideas anyhow. Are you sure you got the right amount of grain? Have you checked your hydrometer in water to see if it's reading about 1.000? Did the crush look different than your normal crush?

 

[ColoHox]

Your crush could certainly be an issue. Did you have a look at it before brewing? Testing different mill gaps between beers changes my efficiency a lot.

If this was the first brew on a new system, I would expect a bit of a learning curve until everything gets dialed in. What was your mash temp? Are your thermometers calibrated? A longer mash can help to get full conversion, but it's possible in 60min. An iodine starch conversion test will help you determine if you have mashed long enough. Did you leave much wort behind in your mash tun or check the gravity of your final runnings? Was there any channeling in your mash or did you stir it at all? How hot was your sparge?

Water chemistry and pH can play a role, but I wouldn't expect any issues with that grain bill.

I know a lot of the things I mentioned are probably "too late now" questions. I mention some of them just as a heads up or as tools to keep in mind for your next batch.

 

[johngaltsmotor]

You say it's a new 3-tier system, what all is new? everything? or just combining it on a new frame? Have you been using the same MLT? Is it a HERMS/RIMS to ensure uniform mash temperature? More details on the equipment (especially what is new) than the recipe would be helpful.
Big beers tend to be lower on efficiency but I wouldn't expect you to drop from 75% to 50%.

 

[MKBoitnott]

Man that is really unfortunate, and really disappointing. I think you could be right about their crush. Im wondering if it even crushed at all. That seems so odd.

I dont think it could be the mash time. Maybe that would put you off by a few points, maybe even 10, but 40?!?! I would think thats pretty unlikely.

You mentioned that youve been brewing for 3-4 years, so I would imagine all the potential measurement errors are also unlikely...

My only other guess would be that they gave you the wrong amounts or something. Unlikely, but a 40 point difference boggles my mind.

Keep us posted if you find anything out.

 

[mrdauber64]

Higher gravity beers require you to sparge longer and boil longer(to get to your target volume) to get a better efficiency. It's not uncommon to be in the 50's or 60's for efficiency on higher gravity beers.

Every time I do high gravity beers(1.80 and higher) I tend to be in the 60's for efficiency. On normal gravity beers I am between 75 and 80%.

 

[btsbrewing]

Thanks for the quick replies everyone, getting this feedback is awesome.

So after we cooled the wort and took our shocking gravity test, I right away tested the hydrometer and it measured correctly, 1.000 in water, also cross checked our thermometer with thermometer on the fermenter and they were identical.

So the new setup, just a simple wooden structure that we made a few weeks ago, we also bought a new keggle and new banjo burner for the HLT, other then that all the equipment was the same, our mash tun is a converted Rubbermaid cooler.

Also, I should of mentioned that before this batch we have always batch sparged, but with this new setup we decided to use a fly-sparge. It went smoothly, we adjusted the outlet to the boil keggle and input into the fly sprage so that it was flowing smoothly with out disrupting the grain in the mash.

I think either the grain wasn't ground correctly or we screwed up when we fly sparged, maybe sparged to quickly?

 

[MKBoitnott]

I think either the grain wasn't ground correctly or we screwed up when we fly sparged, maybe sparged to quickly?

Others can correct me here, but I am still thinking that you would have to MASSIVELY screw up the fly sparge to get 40 point drop. I did the math and thats going from 75% to 40% (soooo loooowww). I would think thats pretty unlikely. Crush is certainly as issue, but once again they would have had to screw that up pretty bad.

Maaaaaaaaaaybe its a combo of both. Or some other issue.

Either way, you can look forward to a session stout. What yeast did you choose? and how much?

 

[btsbrewing]

Yeah I am leaning towards a combination of poorly ground grain and an error in our sparging and/or sparge temp. We started to sparge at 170degrees but we turned off the burner, so the temp could of dropped a lot by the time we finished sparging.

We used Belguim Abbey 11 Wyeast 1762, and pitched 3 packets of yeast into the wort.

Yeah, even though we wont hit our intended ABV we will still be enjoying a nice session stout

 

[tally350z]

How long did you sparge take? Also what type of sparge arm do you have. Could have had an issue with channelling in the mash and that would cause a really inefficient fly sparge.

 

[btsbrewing]

How long did you sparge take? Also what type of sparge arm do you have. Could have had an issue with channelling in the mash and that would cause a really inefficient fly sparge.

I would say that sparging took maybe 30 minutes? We didn't keep track of the time, which we should of. We are using a home building spinning fly sparge out of brass tubes. It did stop spinning at times when the water level in the HLT was low, but we kept it spinning the best we could, I don't think we had any channeling issues, but we might of easily when the fly sparge stopped from time to time.

How long should sparging take on a 10 gallon all grain mash?

 

[bajaedition]

there is a good book on high gravity beers
Scotch Ales
after reading it you seem to realize that you need to approach high gravs a bit different that regular beers
and also that with those huge grain bills you can brew 2 beers, there are that many sugars present
Doing what is called a double mash, where you divide the mash in 2 and take the first 5/1/2 gallons of both mashes toward the high grav and the second run for the small beer is an option to get the best results

also, it is not uncommon to have to pitch twice on a high gravity beer, on my imperial stout I pitch twice, the secomd tie using white labs high grav yeast, first pitch is London

another point you will read in the book is about the size of your starter

good luck

 

[BulldogBrewer]

Also, I should of mentioned that before this batch we have always batch sparged, but with this new setup we decided to use a fly-sparge. It went smoothly, we adjusted the outlet to the boil keggle and input into the fly sprage so that it was flowing smoothly with out disrupting the grain in the mash.

I think either the grain wasn't ground correctly or we screwed up when we fly sparged, maybe sparged to quickly?

Others may disagree with me, but I think this could be it. How fast did you sparge? the very first time I fly sparged I missed my gavity by 30ish points, so it's totally possible.

 

[ChadRabbit]

Others may disagree with me, but I think this could be it. How fast did you sparge? the very first time I fly sparged I missed my gavity by 30ish points, so it's totally possible.

You DEFINITELY want to fly sparge slowly. I wouldn't say that it will drop your efficiency by 30 or 40 points but sparging too quickly will definitely play a role in leaving behind some good fermentable sugars. This mixed with a light crush and high gravity. Makes sense.

 

[SudsyPaul]

I would say that sparging took maybe 30 minutes? We didn't keep track of the time, which we should of. We are using a home building spinning fly sparge out of brass tubes. It did stop spinning at times when the water level in the HLT was low, but we kept it spinning the best we could, I don't think we had any channeling issues, but we might of easily when the fly sparge stopped from time to time.

How long should sparging take on a 10 gallon all grain mash?

Your efficiency shouldn't have been THAT bad. What was the temp in the HLT while you were fly sparging? I'm not sure how much it changes for higher gravity beers, but the fly sparge usually takes about 60-90min when my friend and I do it.

Did you stir the ever loving crap out of the mash when you tossed in your strike water? What was your mash temp? Did you lose a lot of temp while mashing? If you didn't recirc, did you give it a good stir before sparging (I find this helps for fly as well as batch)

It'd have to be a nasty crush for your grain to give you 40% efficiency. I'm pretty sure you'd get that from just hitting your grain with a rolling pin for 2 minutes.