Low OG with brewzilla BIAB?

[SanPancho]

been out of brewing regularly for a while. over past year been trying to get back at it, but the few and far between brews leave me constantly forgetting things about my system or just being out of practice. sucks. having issues with low efficiency on my OGs. i use brewers friend and calc for final kettle volume. so the efficiency here is ending kettle efficiency. used to be around the 70-73% area, doing small dunk sparges. stopped that to avoid oxygenation, and now just do full volume. was getting closer to 67-70%. but last three brews have gone way under the mark. im talking an OG of 1050 came out at like 1040, or 1045 came in at like 1037. sizeable underperformance.

adjusted mill, which i believe is now in spec at .025. got a separate cheap mill for rye,oats,wheat,etc thats at .20.

use BrewNwater for ph. although i've been lazy about checking. but i dont think ph would get me 20% off of my target. especially as we have pretty soft water to being with.

one thought occured to me- i might be bunching up grains and not getting good circulation throughout the grain bed. in an effort to limit air flow, i typically pull the top of the grain bag through the hole in the lid of the brewzilla. i then run a tube off the pump arm down into grain bed and run a slow recirc. maybe im compressing the grains too much by this? too slow of a recirc ? too fast?

im stumped and its annoying the hell out of me. i know grains are cheap blah blah blah but i'm already getting towards 10# in that thing and i'd rather not keep adding more.

anyone have an experience like this? see a similar problem?

 

[Willy]

Yeah... I lost efficiency when I went to a no sparge brew day. I tweaked my BrewFather a little bit and ended up with a slightly larger grain bill (10 lbs went to about 10 + 6-9 oz, not a big deal ).

My other mistake was adding a bit too much water. So, i adjusted. Now using about 7.5 gallons of water for a 5.5 gal batch size. (I lose about one gal in boil off and one gal in the grains and mash evaporation. )

And... I started using a ratchet strap on the BIAB bag as it drained. Just wrap the strap around the bag twice and connect the 2 hooks of the strap. Crank it down... And crank it again... And again. Feels like your milking a cow. I keep doing this until I reach my desired preboil volume.

Good luck. Keep plugging away and find your sweet spot.

 

[hungupdown]

I use a BZ with recirculation, but never tried with a bag, or no sparge.
I found that dry pre mixing the grains, gives most reliable recirculation.

Leaving the malt (pipe) draining into a bucket, for most of the boil. Can produce an extra 5%.

 

[SanPancho]

Yeah... I lost efficiency when I went to a no sparge brew day. I tweaked my BrewFather a little bit and ended up with a slightly larger grain bill (10 lbs went to about 10 + 6-9 oz, not a big deal ).

My other mistake was adding a bit too much water. So, i adjusted. Now using about 7.5 gallons of water for a 5.5 gal batch size. (I lose about one gal in boil off and one gal in the grains and mash evaporation. )

And... I started using a ratchet strap on the BIAB bag as it drained. Just wrap the strap around the bag twice and connect the 2 hooks of the strap. Crank it down... And crank it again... And again. Feels like your milking a cow. I keep doing this until I reach my desired preboil volume.

Good luck. Keep plugging away and find your sweet spot.

im right about 7.5 as well. and i squeeze like a 14 year old on his first date.

just not getting enough sugars. even when i lower my efficiency estimate, i'm still off. theres something going on with conversion. either bad/no recirc. pH is off a ton. or crush is off by a mile.