Why am I not getting good extraction?

I have an issue regarding my latest brew attempt – a Three Floyds Alpha King clone. Here’s the bill:

12 lbs. - 2 Row Pale Malt (Rahr)
1 lb. - Crystal Malt (60L)
1/4 lb. - Special B Malt
1/8 lb. - Melanoidin Malt
1 oz - Centennial (60 min.)
1/2 oz - Warrior (30 min.)
1 oz - Cascade (15 min.)
1.5 oz - Centennial (5 min.)
1 oz - Centennial (Dry Hop)
1 oz - Columbus (Dry Hop)
White Labs California Ale Yeast (WLP001) - 1800 ml starter

I plugged this in to Beersmith and was looking at an OG estimate of 1.073. Well, I missed the OG pretty significantly coming in at 1.050. I added 3/4 lbs of DME (it's all I had on hand) to get up to 1.053. I thought I did the mash to perfection, but still didn’t get the extraction that I was hoping for. My grain is from a supplier that pre-milled it and I even went as far as to give it a rolling pin work over just to try to help max out extraction. I mashed for an hour hitting my temp of 150 right on the nose. I batch sparged with 170 degree water letting it rest for 10 min before draining. I’m just utterly puzzled at how I missed my OG by so much. Any ideas? I’m perplexed.

One or two sparges and did you stir well after each add?

It sounds like you're using what I'd consider a typical moderate efficiency technique.

From my page: http://www.suebob.com/brew/allgrain.htm

Ok, all the basic theory aside. Here's how I brew all grain and get a consistent 88-92% efficiency using the Batch Sparge Technique. First, the key points I like to stress about my process are:

Fine Crush - The picture of crushed grain above is actually a little more coarse than I use. I like to see a bit more flour in the mix. If you find that you're getting a lot of slow runoffs or "stuck" sparges, you might have gone too fine. This is hard to control when you buy your grain pre-milled. This is one of the reasons I bought my own mill.

Thicker Mash - We discussed this earlier on but a mash of 1.25 qts/lb or slightly less leaves a ton of extra volume for sparging. I like that.

Stir Well - You must stir well at a few stages of the process. First is when you dough in, any dry spots will NOT convert. No dough balls! You also must stir well after every sparge infusion to fully diffuse the sugar into the water.

No Mash Out Infusion - A mash out is a carry over from fly sparging. In the case of a cooler MLT, many brewers will add a small amount of very hot (sometimes boiling) water to the mash just prior to the sparge to get the grain bed temp up into the high 160's F. I have not found this to be beneficial given my technique and in two test cases it dropped my efficiency 4%. Leave more water for discrete sparge infusions and just drain the first runnings before adding new water.

Hot Sparge - Given that I skip the mash out infusion, I still want to raise the grain bed temp up into the 170F area. In most cases this means sparging with 180-185F water.

Double Sparge - If you need to sparge with say 4 gallons to reach your desired pre boil volume, instead of adding 4 gallons at once, add half, stir, vorlauf and drain. Then do it again with the remaining 2 gallons. Think of washing a glass in the sink. Which gets more soap off; filling it all the way, swishing it then dumping or filling it half way, swishing, dumping and repeating? Goofy analogy but it really works. Now, if you'd like to read a little more on why I think this happens, wikipedia has an article on diffusion (which is the principal at work in sparging).

Two batch sparges will help increase your efficiency, but for you to be off by that much I'd almost wonder how long the grain sat around after it was crushed.

david_42 said:

One or two sparges and did you stir well after each add?

Click to expand...

One sparge, and yep, I stirred very well.

Should I be taking a gravity reading after sparging and draining, but before the boil just to see if I need to keep trying for better extraction, or is that not going to be an accurate reading?

Once you've sparged and collected your desired preboil volume, there's not much you can do to get more extraction. However, this is where you'd decide to augment the gravity with a little malt extract if necessary. Don't forget that the gravity is going to go up as the boiled wort condenses though. Preboil OG is NOT the same as post boil.

Jack up your sparge temp and split it into two discrete infusions and you'll see the efficiency go up.

I really like the idea of double sparges, but it seems to me that they are only effective on low gravity beers. How do you come up with enough sparge water to cover your grain bed when doing a high gravity beer. Do you just cover the grain bed with water, regardless of volume, and then drain till you are "at volume" in the kettle?

Simple answer to that, sulli, is to use a larger MLT! If you already have your sparge water measured out, just keep adding it, mixing, and draining. This is only for batch sparging though, with fly sparging it's not an issue.

Ok... so let's say I'm brewing the 888 Russian Imperial Stout, for example. This wonderful sounding beer has a grain bill of about 18.20 lbs @ 75% efficiency. I'm shooting for 5.5 gallons of wort. This means I need 7.11 gal. of mash water, which leaves me with 2.71 gal. of sparge water. If I split that 2.71 gallons of water in half, I'm left with 1.35 gal. for each sparge. Please correct me if I'm off base here, but 1.35 gal. of water is barely going to re-wet your grain. I don't see how it could be very efficient at rinsing the sugars from the grain. Am I missing something here.

Yea, you're not using nearly enough water. You don't calculate efficiency first, you use water enough for to get to your boiloff point. I don't know how you're getting your numbers. Mash water is generally 1.25 quarts per lb of grain, so for 18.20 lbs of grain you'd use about 5.6875 gallons of mash water. Sparge water is generally 0.5 gallons of water per lb of grain, so you'd use about 9 gallons of sparge water. you'd drain out the mash water, then add 4.5 gallons of water. vourlaf then drain into the boiler, then add the next batch of 4.5 gallons of water.

Sully is right... on huge beers you can't really double sparge it. You just have to accept the lower efficiency.

[size=+1]Ingredients:[/size]
18.2 lb Pilsner Malt

[size=+1]Schedule:[/size]


00:30:49 Mash In - Liquor: 5.75 gal; Strike: 164.46 °F; Target: 152 °F
01:30:49 Sac Rest - Rest: 60 min; Final: 152.0 °F
01:40:49 Batch Sparge - First Runnings: 0.0 gal sparge , 3 gal collected
; Batch 1: 1.66 gal sparge @ 180 °F, 1.66 gal collected, 5 min; Batch 2: 1.8 gal sparge @ 180 °F, 1.79 gal collected, 5 min; Total Runoff: 6.58 gal


You can see how you'd never get 18lbs of grain with only 1.6 gallons of sparge. I'd just go ahead and add the full 3.5 gallons of sparge in one shot. However, this is a great reason to do a partigyle so you can use all the leftover sugar for a small beer.

How much water did you use?