Super low efficiency on first couple of all-grain batches - troubleshooting

[thasnazzle]

So we just switched over to all-grain and are having some issues with efficiency. I'm using Brew Pal for iOS (which is awesome) to do the math and have been using the default 75% efficiency setting. Both of our all-grain batches have come in well below what that 75% efficiency would predict. Yesterday we brewed a BPA with an expected OG of 1.048; after the boil we measured an OG of 1.032. I'm not a math whiz but I'm guessing that puts our efficiency around 50% (2/3 of the 75% predictor we used).

I'm trying to figure out where we're going wrong. Here's the process we're using:

- 60 minute mashes in a cooler mash tun. We are doing this on the cheap, so instead of spending like $75 on a false bottom we have been using huge grain bags. I think they're 23 x 25 in. bags from Austin Homebrew; we've been using one bag for ~10lbs of grain. I've included a picture of this below to give some perspective - bag covers the length and width of our cooler and the grain appears to be sitting pretty loosely in it.
- Our sparging process is something like this: we drain off the first runnings (that's the water that's mashed in, right?) and then add sparge water, draining that off while stirring the grains as much as we can to make sure it's all getting sparged. I'm not sure what kind of sparge this is - batch?
- all of the first runnings + sparge water go in the boil kettle. We do full boils.

I feel like I'm probably missing some really basic thing here. My best guess is that the grain bags might be too small for all the grain we're using and so we're not converting as well as we could be. I'm thinking to remedy this I might get a screen to fit through the inside of the cooler to use instead of mashing inside bags. Something like this: http://www.austinhomebrew.com/product_info.php?cPath=178_33_82_88&products_id=12687

What do you think, HBT?

 

[Srceenplay]

I'm on my second AG too.
Both of mine had a 66% eff.
I use a 10 gallon igloo with a braid.

Here are my thoughts on what might help me.
The only two thing that I can think of to maybe help me are
1. I'm draining to fast. Each runnings took about 20 min each.
2. Maybe my mash out water isn't hot enough?
It's been around 175-180*.

 

[Yooper]

So we just switched over to all-grain and are having some issues with efficiency. I'm using Brew Pal for iOS (which is awesome) to do the math and have been using the default 75% efficiency setting. Both of our all-grain batches have come in well below what that 75% efficiency would predict. Yesterday we brewed a BPA with an expected OG of 1.048; after the boil we measured an OG of 1.032. I'm not a math whiz but I'm guessing that puts our efficiency around 50% (2/3 of the 75% predictor we used).

I'm trying to figure out where we're going wrong. Here's the process we're using:

- 60 minute mashes in a cooler mash tun. We are doing this on the cheap, so instead of spending like $75 on a false bottom we have been using huge grain bags. I think they're 23 x 25 in. bags from Austin Homebrew; we've been using one bag for ~10lbs of grain. I've included a picture of this below to give some perspective - bag covers the length and width of our cooler and the grain appears to be sitting pretty loosely in it.
- Our sparging process is something like this: we drain off the first runnings (that's the water that's mashed in, right?) and then add sparge water, draining that off while stirring the grains as much as we can to make sure it's all getting sparged. I'm not sure what kind of sparge this is - batch?
- all of the first runnings + sparge water go in the boil kettle. We do full boils.

I feel like I'm probably missing some really basic thing here. My best guess is that the grain bags might be too small for all the grain we're using and so we're not converting as well as we could be. I'm thinking to remedy this I might get a screen to fit through the inside of the cooler to use instead of mashing inside bags. Something like this: http://www.austinhomebrew.com/product_info.php?cPath=178_33_82_88&products_id=12687

What do you think, HBT?

The technique (yes, it's batch sparging) looks good, except you don't need to stir while you drain. You want to "vorlauf" (recirculate the first bit of runnings) so that your run off is clear wort.

The best guess I have is that even though the bags seem loose to you, I think they must be too tight. You can try bigger bags, or a toilet braid type of screen so that you don't use a bag at all.

 

[Yooper]

I'm on my second AG too.
Both of mine had a 66% eff.
I use a 10 gallon igloo with a braid.

Here are my thoughts on what might help me.
The only two thing that I can think of to maybe help me are
1. I'm draining to fast. Each runnings took about 20 min each.
2. Maybe my mash out water isn't hot enough?
It's been around 175-180*.

1. You can't drain a batch sparge too fast- the run off is just as fast as it goes. It takes me less than 5 minutes.
2. You don't have to mash out with batch sparging. You can, of course, but I don't see any advantage. I think you'd get better efficiency with draining your mash, and adding all of the mash out water to the sparge water. In general, the more you sparge (within reason!) the more you get out of the grain.

 

[hops2it]

If your strike temps are good and you're getting good conversion, I'd try to exchange the bag for a braid or manifold although the latter is more money, more work and not necessarily better. Not sure but maybe possible you are unable to get good stirring in that bag and that could nail you twice...the initial mix and after adding sparge water.

Other possibility if you are getting your grains from the same source each time, is an inadequate crush.

 

[chickypad]

In addition to Yooper's suggestion you might also check the crush. Since you're using a bag in the cooler you can go pretty fine. Did you crush your own? It seems a lot of LHBS standard crushes are more coarse than what many of us use.

Edit: oops, beat me to it. I will say that I get great efficiency on small all grain batches using a bag in cooler the way you are, OP. As yooper says though, it needs to be loose.

 

[RM-MN]

I'll add my voice and say crush is your problem. looking at the picture I can see what looks like whole grains. You never see whole grains in mine. Not using a bag, you don't. You don't even see whole husks in mine. It looks more like a coarse cornmeal.

I also do a 30 minute mash because it's done by then. If you need all 60 minutes, your crush isn't fine enough.

 

[thasnazzle]

Hmm. Austinhomebrew is my LHBS, and I get my grain crushed there. I haven't had problems with being significantly off when doing partial mashes (generally trying to get ~8# of grain mashed on the stovetop to retain as much control as possible). Of course, if any of you have experience iwth their crush on AG batches that says otherwise, I'm not discounting that it's possible.

I'll try switching to a braid setup and see if that makes any difference. Thanks, all.

 

[jaydog2314]

I'd agree with the rest about the crush. I know my first all grain I was forgetting to adjust my hydrometer readings for the wort temperature. I thought my first AG was way off but I never converted the readings so it was probably a lot better than I thought. Simple mistake I will never make again.

 

[doby]

Looks to tight to me, get the braid you can stir eiasier