Low OG - IPA

Just brewed a 10gal all grain IPA.
Here is the bill: 24lb 2-row, 1lb Cara-pils (40l), 1lb Crystal (45l)
Mashed 4gal H2O at 156 degrees (strike @ 168) - Gravity 1.056
Sparged total 8gal H2O (3gal wort + 5gal clean H2O / heated to 171 degrees) - Gravity 1.043

Added to boil- 1.5lb Corn Sugar and additional 5gal H2O (13gal boil) - Gravity 1.034

90min boil with numerous hop additions throughout and gravity after boil read 1.036 @ 70 degrees. This what concerns me. To reach 4-5abv I would need the final gravity to reach almost zero. Is this acceptable or did my numbers get askew by adding to much water to the sparge?

I would guess the main problem was caused by mashing 26 lb grain in 4 gal water. That's a mash thickness of about 0.6 qt / lb.
You need at least 6.5 gal strike water, and preferably 8 gal to mash 26 lbs grain. 4 gal water won't wet all the grains. Also 156F seems to be a very high mash temp for an IPA. I think 150 - 152 would be more normal.

-a.

I agree. I typically mash in with about 4 gallons for 5-6 gal batches with half that grain bill.

4 gallons is really low. Also adding five gallons of water AFTER sparging is excessive too. You should have mashed with much much more water and reached your boil volume without having to top up. I'm not saying adding extra water after mashing is wrong, but five gallons worth is too much.

I agree with everyone on here I usually mash 12lbs of grain with 4 gallons of water. I prefer anything over 1.2 quarts per lb up to 1.8

I mashed 16# of grain with 5 gallons of water yesterday for a 5.5 gallon batch. Looks to be that you had a very very thick mash (as stated by everyone else here as well).

My mash tun is a 48Qt cooler and after I put in the grains, I added the strike water. The water level was approximately 1/4" over the grain bed after stirring it in. I'm going to guess that my water amount was greater than 4 gal. Maybe my Hydrometer needs to be calibrated? or maybe my thermometer was way off. Either way, I will see what happens.
Thanks for all the advice/replies! Cheers!!

Yeah if you got 3 gallons of first runnings you probably mashed with about 6 gallons, because that much grain would absorb about 3 gallons. Still a little on the thick side, but better than 4 gallons. Most folks would have done a second sparge rather than just topping off in the kettle with that final 5 gallons, so you probably lost some OG points there as was mentioned. Still, 1.036 for a post boil gravity with that grain bill is exceedingly bad efficiency - like 38% if my quick calcs are right. Definitely check the calibration on everything - hydrometer, thermometers. Have you done other all grain batches and if so what was your efficiency like? Do you crush your own grains?

Edit: just realized I calculated your efficiency without the corn sugar. Taking that into consideration your numbers are a little worse.

How long did you mash? I'm just curious. I still say it's the massive amount of top up water.

OK. If you got 3 gallons of first runnings, you must have used at least 6 gallons strike water. Let's assume that you used a mash thickness of 1 qt per lb.
That means you would use 6.5 gallons strike water for the mash. You would lose 3.12 to grain absorption and lose a small amount to dead space in the tun, so you could collect ~ 3 gallons of first runnings.
You say you then sparged with a mixture of 3 gallons of wort (I assume first runnings) + 5 gallons water.
I have two problems with this:

1. Why would you add your first runnings to the sparge water? They will already have a high gravity, and adding them to the sparge water will dilute them resulting in a considerable loss of efficiency.
2. 26 lbs grain mashed at 1 qt / lb + 5 gallons water has a volume of 54.32 qt, but your cooler only holds 48 qt. You may have mashed at a bit less than 1 qt / lb, but there's no way that you could collect 3 gallons first runnings and fit those runnings + 5 gallons in a 48 qt cooler. It is however possible that you are fly sparging, in which case you should not have drawn off your first runnings before starting the sparge.

The next thing is that you then topped off with 5 gallons of water. As vinnythering said, this is excessive. You should have used the second 5 gallons to perform another sparge.


If you want to determine the cause of your poor efficiency and correct it, then:

1. You must pay much more attention to your volumes
2. You must use at least 1 qt strike water per lb grain for the mash (and preferably 1.25 - 1.5 qt / lb)
3. Batch sparge
4. After draining off the first runnings, don't add them back to the sparge water. Keep them in the kettle.
5. After adding the sparge water, stir till your arm feels like it is dropping off, and then stir some more.
6. Don't top off in the kettle with large amounts of water. If you are short on volume, you need to do another batch sparge.

You can also get an idea as to where the problems are occurring by taking samples of the first, second, and third runnings, cooling them to the hydrometer calibration temperature, and then taking gravity readings. Armed with that information and accurate volumes, http://braukaiser.com/wiki/index.php?title=Understanding_Efficiency can help you to diagnose the cause of any problems.


-a.

AJF- You hit it right on the head.
I generally drain the first running straight into the boil keg but this tme, for some reason, I ran it back into the HLT and topped it off with 5gal (8total) and heated it then fly sparged into the kettle. I'm usually pretty good about maintaining accurate readings while brewing.
A few other things I did wrong was not stirring nearly enough while sparging and adding to the kettle instead of performing a 2nd and/or 3rd sparge.
Thanks for the replies!

vinnythering said:

How long did you mash? I'm just curious. I still say it's the massive amount of top up water.

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60min