Help my diagnose by 55% efficiecy...

[Newton]

I've done 7 all grain batches now and my efficiency is averaging around 68%. I do a single infusion batch sparge method as John Palmer recommends. I've been using Beer Smith to calculate my infusion temperatures and volumes. Today I did a 55% efficiency, but it wasn't a disaster because I originally figured on 5.5 gallons and I boiled it down to 5 and ended up just under my target OG.

Here's my grain bill:

6.75 lb Pilsner (2 Row) Bel (2.0 SRM) Grain 56.25 %
4.25 lb Wheat Malt, Ger (2.0 SRM) Grain 35.42 %
1.00 lb Wheat, Flaked (1.6 SRM) Grain 8.33 %


Here's my mash and sparge:

Mash Name: My Mash Total Grain Weight: 12.00 lb
Sparge Water: 3.24 gal Grain Temperature: 72.0 F
Sparge Temperature: 168.0 F TunTemperature: 72.0 F
Adjust Temp for Equipment: FALSE Mash PH: 5.4 PH

My Mash Step Time Name Description Step Temp
60 min Single Add 18.00 qt of water at 162.8 F 153.0 F


I hit everything on target...stirred the grist at 30 minutes in and the temp was still at 152. I ended up doing 75 minute mash.


Any suggestions as to why I got such a bad efficiency on this one?

 

[todda00]

Do you mill the grain yourself? If so, have you tried making a finer grain? If you get your grain pre-milled, you might want them to ask to make it finer. You can't go too fine, otherwise you will risk a stuck sparge.

Are you sure they thermometer is still working properly?

 

[ajf]

Did you drain the first runnings before adding the sparge water? If not, that will contribute to low gravity.
Did you stir the sparge water in really well before vorlaufing and draining? If not, that would explain the low OG.
It looks like you are only collecting about 6g wort pre-boil, possibly 6.25. That looks very low to me if you are aiming for 5.5g. I start with 7g, and end up with 5.25 in the fermenter, but I lose a little bit to equipment, trub, and hops, and boil for 75 minutes.
If you can sparge a bit more, and boil off a bit more, then that will increase your efficiency a bit.

Hope this helps.

-a.

 

[Newton]

Could one of the reasons be that I didn't do a multi rest infusion? I did a wheat beer last month with more normal efficiency, but the difference with that one is that I used flaked wheat instead of malted wheat. ?