Mash Efficiency

[AndMan3030]

I have recently installed a 'pico style' false bottom in a keg and installed a dip tube/bulk head. I also just got an 809 March Pump for recirculating my mash. My last beer finished much lower than expected. the recipe is as follows:

25 Lbs 2-Row
1.5 Lbs Crystal 40
1.5 Lbs Crystal 8
1 Lb Carapils
2 Lbs Cane Sugar

Filled my keg with water until the water was level with the false bottom. then added my strike water at 1.25 quarts per pound, which was rounded to 9 Gallons of water. I mashed at 154 degrees for an hour, recirculating for the last 30 min. I did not stir my mash mid mash which may have been my mistake, however I have not had problems with that before. I did dough in very slowly while stirring. Anyway, I collected 14 gallons, hoping to end up with 12 after the boil.

Added 2 lbs of sugar with 10 min left to boil. I was hoping for 1.075. Ended up with 1.062.

Any thoughts/advice on improving my efficiency? I used to get roughly 80% from my cooler system. I would like to get 75%. This last brew was down around 62% which is unacceptable.

Thanks in advance, I am loving this site!

 

[Pappers_]

It could be something to do with your false bottom and new mashing method, getting everything locked in. But it also occurs to me that it might be a decrease related to how big the beer is - I usually start to notice a decline in efficiency starting around a target gravity of 1.070.

 

[helibrewer]

I've started taking gravity readings from the MLT during mashing. This way I know my conversion efficiency. Braukaiser has a chart of maximum theoretical conversion: See Table 1. I'm always in the mid 90% range so I know any reduction in efficiency is happening AFTER the MLT.