consistency issues is it the grain..

[deviantwarthog]

grain bill #1
12# british 2 row,2#victory,.75#flaked oats,.25#black patent[15#tot]
mash temp 152 1/1 ratio 1 hr
sparge 4.5 gal 170 65 min
collected about 6.5 gal
wert gravity 1.067

grain bill #2
12#am 2 row pale,1.25# am. munich lt,.5# crystal 60L,1.25#carapils{15#]
same mash temp,ratio & time as above
same sparge as above
collected about 6.5gal
wert gravity 1.051!!??

i use good ole casselberry city water run thru a pur filter
all grain is from LHBS hearts in orl.
i used exactly the same methods w/both
why is my pale wert grav so low?
I've brewed the pale twice w/same poor result.
any advice would be greatly appreciated.

 

[afr0byte]

Was the crush the same? Did you somehow have more channeling in the sparge for the second beer? Also, does your city use different water sources sporadically? If you happened to get high alkalinity water for your second beer your pH could have been out of the optimal range, and thus your second beer might not have been fully converted>

 

[deviantwarthog]

Was the crush the same? Did you somehow have more channeling in the sparge for the second beer? Also, does your city use different water sources sporadically? If you happened to get high alkalinity water for your second beer your pH could have been out of the optimal range, and thus your second beer might not have been fully converted>

i buy the grain crushed fromthe LHBS,i didn't notice anything out of the ordinary. i have noticed a trend with my past brew logs.i get better eff.
on all dark beers. i do stir the top of the grain bed when i sparge.
thanks dw.

 

[afr0byte]

i buy the grain crushed fromthe LHBS,i didn't notice anything out of the ordinary. i have noticed a trend with my past brew logs.i get better eff.
on all dark beers. i do stir the top of the grain bed when i sparge.
thanks dw.

Your dark malts are likely helping to lower the mash pH some (offsetting some of the alkalinity).