first time calculating AG brewhouse efficiency - 50%?

[twd000]

I have brewed all-grain for about 2 years now; never too concerned about hitting #'s but the beers turned out decent. Mostly recipes from Brewing Classic Styles

Recently took 6 months off brewing due to moving. Built a boil keggle in the meantime, first time using it.

Brewed the BCS Saison recipe last weekend, got the grains milled by Brewmaster's Warehouse. I didn't verify the weight of the grains, but I assume they packed it correctly.

I ran 6 G into the mash tun (10 G Rubbermaid) as usual, mashed at 152-148 for 60 minutes, ran off 4G of 1st runnings, then 2.5 G of second runnings. Gravity was 1.022 at 100 F, didn't take the time to cool the sample, but ran the grain bed dry and figured it was getting thin enough.

Boiled an hour, then chilled and setup pathetic whirlpool with pellet hop soup in the last 3/4" of sludge in the bottom of the keggle. I don't have a screen or anything, just an elbow that extends a little above the curve of the bottom.

Anyways by the time I finished chilling then racking off the cold break, I yielded 4.2 G of 1.054 wort at 65 F. Significantly less volume and gravity than I expected.

http://www.brewersfriend.com/brewhouse-efficiency/
This site tells me I achieved only 50% brewhouse efficiency; where did the rest of my sugars go, and how can I improve my process next time?

 

[AT-JeffT]

how many lbs of grain total?

 

[twd000]

12 lbs of grain, mainly Belgian Pilsner malt

 

[RM-MN]

Efficiency depends on a few things. First is conversion. If the grains are not milled fine enough, you won't get full conversion. This is one of the most common problems. It's also why so many of us have our own mills. Second is extraction. Sparging is the step where you finish extracting the sugars from the grains as the first runnings are saturated with the sugars and adding water to the mash tun lets you dilute the sugars and get more of them out. This requires stirring, lots of stirring. You may also need a second sparge step to get the rest of the sugars out. Third is losses. If you leave anything in the mash tun, that is a loss of sugar. When you whirlpool, you leave sugars behind. Fourth is measurement. Every measurement has the possibility of errors. You may have a hydrometer that is off or you may not have measured your final quantity correctly. All of these factors add up.

 

[helibrewer]

So you are running a mash ratio of 2.0. With that ratio you should be seeing gravities in the high 1.050's to 1.060 for your unsparged first runnings. If you are not, then your mash is the problem, either crush or temperature control.

Once you have your conversion efficiency fixed, you can address your sparge...i.e., hittting your pre-boil volume and OG. Kettle loss would be the final variable for overall efficiency.

Whirlpooling will not change any of your numbers, it is just a good technique for settling your trub....do it for about 15 minutes then let the wort settle for a good 30 minutes before draining. Once you figure out your trub loss you can adjust your recipes to attain the final bottling volume you want.

Read through this, it's a great rundown on efficiency:
http://braukaiser.com/wiki/index.php?title=Troubleshooting_Brewhouse_Efficiency

 

[twd000]

to be clear, I am not diluting the first runnings; I drain that wort completely before adding sparge water

MY initial mash was high; probably 158 so I did a lot of stirring to get it down to 152

I was also measuring pH and adding lactic acid so there were a lot of variables in that first 15 minutes

is there anyway for me to get a finer crush without investing in a mill? Can I take the pre-crushed grains and just smash them with a rolling pin?