Brewzilla BIAB no sparge efficiency problems

[SanPancho]

brewzilla brewhouse, brew'n'water, and software is brewers friend- 55% ending kettle efficiency. ouch. has happened multiple times recently. thought i wasnt crushing my wheat or rye, which are in alot of my beers. but after getting a separate mill for .020 milling of those, no change. main mill is set at roughly .030 recently. typically shoot for 5.4pH. 7.25 gals of water, yesterday was 12# of grain- 7 base, 2 wheat, 2 vienna, 1 carafoam.

did 25min at 146ish, then 20 at 157ish, then 10 min mashout. pre boil gravity was only 1036/1037. i had about 6.25 gals after squeezing the **** out of the bag. after boiling down to just under 6gals, i'm at like 1038/1039 OG. ugh.

i had recirc going pretty slow. maybe too slow?
i slowly lower bag into brewzilla, hard to believe it could be dough balls.
double crush? take the main mill down to like .025 ?

the reason im frustrated, is that i used to get like 65-70%. besides mill settings, i dont recall any real difference in process. maybe i'm doing recirc too slow? i honestly cant think of where this came from. i know grain is cheap. but i'd prefer to figure out why i've dropped roughly 10%. becomes pain in the ass to run old recipes as i cant rely on them.

 

[Zadkiel]

perhaps you could make a list of possible reasons and then do tests to eliminate them - could it be your mill or grain, try buying a recipe of grain crushed and see if the efficiency goes up. Could it be temps, use a second thermometer to check the brewzilla temp against. Use a known weight to check your scales? that sort of thing.

 

[Yooper]

One thing I've noticed with step mashing in the Brewzilla is it takes a LONG time to raise the temperature. I'm using the 240 gen 4, but even so....so I don't step mash anymore. The pump is anemic, even at full throttle, so recirculation is not all that great and the temperature at the bottom when I boil is 219F (which it's not, I know). I accept those limitations, but as an example today I got 100% conversion efficiency according to the software; 80% preboil, and see the rest below:

This has been the pattern over the last at least 8 or so brews, and I use a bag for mashing. I think several things are going on here. First, the temperature between the RAPT probe near the top and the temperature at the bottom is WAY off. My wort does not boil at 218, more like 211. So it's heating quite a bit more at the bottom where the pump is.
Secondly a full volume mash is always giving me less efficiency than a mash/sparge- usually not a lot, but enough to notice.
I've decide to just accept it, as it's 'only' about 8% loss compared to not having the Brewzilla. Recirculation, not recirculation, fast, or slow, etc- doesn't seem to matter.
I know it doesn't answer your issue, but I wanted you to know that it's not just you! It's just not going to seem to give us the efficiency we had in our older traditional systems I guess.

 

[Whisky River]

I think @doug293cz has a spreadsheet he has used to calculate efficiency and with the proper measurements he could use it to diagnose the cause of low efficiency. Maybe he will chime in and share some insight

 

[SanPancho]

perhaps you could make a list of possible reasons and then do tests to eliminate them - could it be your mill or grain, try buying a recipe of grain crushed and see if the efficiency goes up. Could it be temps, use a second thermometer to check the brewzilla temp against. Use a known weight to check your scales? that sort of thing.

kind of already did that stuff. i've checked the mills, they're tight and dont change after running grain through so not a variation issue. temp sensor shows about 212-213F for boil which is good. base malt is always the same, dont really use alot of specialty malt so dont really think thats it. (outside of wheat/rye on the separate mill)

that's why im wondering if im not getting enough recirc. or maybe should double crush. think i'll do both next time.

 

[SanPancho]

One thing I've noticed with step mashing in the Brewzilla is it takes a LONG time to raise the temperature. I'm using the 240 gen 4, but even so....so I don't step mash anymore. The pump is anemic, even at full throttle, so recirculation is not all that great and the temperature at the bottom when I boil is 219F (which it's not, I know). I accept those limitations, but as an example today I got 100% conversion efficiency according to the software; 80% preboil, and see the rest below:
View attachment 883772

This has been the pattern over the last at least 8 or so brews, and I use a bag for mashing. I think several things are going on here. First, the temperature between the RAPT probe near the top and the temperature at the bottom is WAY off. My wort does not boil at 218, more like 211. So it's heating quite a bit more at the bottom where the pump is.
Secondly a full volume mash is always giving me less efficiency than a mash/sparge- usually not a lot, but enough to notice.
I've decide to just accept it, as it's 'only' about 8% loss compared to not having the Brewzilla. Recirculation, not recirculation, fast, or slow, etc- doesn't seem to matter.
I know it doesn't answer your issue, but I wanted you to know that it's not just you! It's just not going to seem to give us the efficiency we had in our older traditional systems I guess.

definitely not the issue im having, but i'm with you on the temp variations. i dont use the rapt, just the bottom probe. and its always boiling at the same temp, so at least that makes sense. but i think i should probably up the recirc, for the reasons noted about equalizing the temps throughout the vessel.

 

[Zadkiel]

definitely not the issue im having, but i'm with you on the temp variations. i dont use the rapt, just the bottom probe. and its always boiling at the same temp, so at least that makes sense. but i think i should probably up the recirc, for the reasons noted about equalizing the temps throughout the vessel.

Are you taking into account the temperature difference between the bottom of the kettle, right next to the heating element, and the temperature in the middle of the mash? I usually see a delta of about 3-5C (5-8F for you US folks) but I've seen others report as high as 12F difference.