New eHERMS setup, low efficiency

[hyperboarder]

Full build details here: https://www.homebrewtalk.com/f51/about-time-document-strut-penrose-bcs-460-system-419733/

I did my 4th batch today, an IIPA. Batches thus far were as follows:

Sierra Nevada Pale Ale clone - Ended up mashing a bit higher than I wanted (156-158, dialing things in), but OG was good. FG was a bit high due to the high OG.

Zymurgy KBS clone - Beersmith and Zymurgy disagreed on numbers (Beersmith was lower and IMO more realistic) and mine lined up closer to Beersmith, though I came in 5 points low on the OG. Can't quite recall the pre-boil. I did have some issues with the chocolate not melting as much as I would have liked, which certainly contributed.

Clone Brews Bitburger Pilsner clone (yeah, I know, 3 clones, trying to dial things in with controls I know fairly well) - I don't recall the pre-boil exactly but it wasn't far off. 3 points low on the OG.

IIPA today - Pre-boil was way low, 13 points (18.5 lbs grain, estimated to be 1.074, hit 1.061). OG was 12 points low. No explanation I can think of.

I've got Beersmith calculating numbers based on 72% which was typically conservative with my cooler setup (fly sparge, typically hitting between 75% and 80% efficiency). Based on the numbers today I was just under 62%. I crush my own grain, Barley Crusher is set at .036" gap. I cleaned and reset the gap between the 2nd and 3rd recipes above. It gives a decent crush, very few whole grains and not too much flour. Mashing with 1.25 quarts/lb grain plus a bit (.5 gallons or so) to account for the additional volume of the HERMS coil. So far all have been single infusion mashes from 60 to 90 minutes with 168 degree mash outs. Fly sparging in the same manner that Kal does, no obvious issues or channeling of the grain bed that I've seen.

What the hell am I missing? It's driving me nuts! Planned next steps are to add a slit hose around the outside of the false bottom (the construction of the Penrose kettles yields a not quite circular outline so I'm going to try and close the small gaps as much as possible) and maybe slow down my sparge. Open to other suggestions though, I'm bummed on the low gravities.

 

[showcow]

Well I was thinking that maybe your lautering was the issue (my first thought was maybe you're fly sparging with a bazooka screen or something.

It's weird also that your eff. is super low considering you were already fly sparging before.

Are your thermometers calibrated to a lab thermometer? If they're reading 5°F high, you may be mashing very low and the enzymes take longer to concert the mash at lower temperatures. Though you said your first beer was 158 so that's weird (edit: this would make sense if your temps are off - maybe you were actually mashing around 152 and got complete conversion and for the other batches you mashed lower and didn't get conversion).

Could it be that your water supply has changed? Water chemistry has a huge effect on efficiency, and if your mash pH is off, it may be one of the issues. Although, I wouldn't think it would be the entire cause of a 15-20 point drop, it may not be out of the realm of possibility.

Edit: after re-reading your post, it's likely water temp I think. Couldn't see on your main post but where is your mash temp probe? Anyway, the iipa would be mashed at the lowest temp so it would make sense that it was the furthest off gravity wise. water chemistry couldn't hurt.

 

[showcow]

Also, in resetting the mill something might have changed about the crush...


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[ballz50401]

Like others have said: Check that your thermometers are reading accurately, mash pH reads 5.5 at room temp, and temperature is uniform throughout the mash recirculationm process. I have noticed some efficiency loss when my hex coil outlet temp varies from my mash temp. I also have noticed improved efficiency when I stir the mash half way through the saccharification rest with above average OG brews. Tightening your mill gap helps too, but there is a fine line between crushing too fine and stuck recirclation and/or sparge.

 

[hyperboarder]

Well I was thinking that maybe your lautering was the issue (my first thought was maybe you're fly sparging with a bazooka screen or something.

It's weird also that your eff. is super low considering you were already fly sparging before.

Are your thermometers calibrated to a lab thermometer? If they're reading 5°F high, you may be mashing very low and the enzymes take longer to concert the mash at lower temperatures. Though you said your first beer was 158 so that's weird (edit: this would make sense if your temps are off - maybe you were actually mashing around 152 and got complete conversion and for the other batches you mashed lower and didn't get conversion).

Could it be that your water supply has changed? Water chemistry has a huge effect on efficiency, and if your mash pH is off, it may be one of the issues. Although, I wouldn't think it would be the entire cause of a 15-20 point drop, it may not be out of the realm of possibility.

Edit: after re-reading your post, it's likely water temp I think. Couldn't see on your main post but where is your mash temp probe? Anyway, the iipa would be mashed at the lowest temp so it would make sense that it was the furthest off gravity wise. water chemistry couldn't hurt.

HLT and MLT probes are in a tee in the outlet, same as Kal's setup. BK probe is in the back of the kettle. All 3 vessels have analog thermometers as well as a sanity check and everything seems to line up. I might look into it further though, nothing to lose.

Water supply has changed a bit, we moved a year ago and I honestly don't recall the efficiency of the batches post-move but pre-electric. They weren't low enough to recall but they may have been low. I don't think the cold water I'm using for brewing has gone through the softener but I'll have to confirm. I know that could throw things.

Like others have said: Check that your thermometers are reading accurately, mash pH reads 5.5 at room temp, and temperature is uniform throughout the mash recirculationm process. I have noticed some efficiency loss when my hex coil outlet temp varies from my mash temp. I also have noticed improved efficiency when I stir the mash half way through the saccharification rest with above average OG brews. Tightening your mill gap helps too, but there is a fine line between crushing too fine and stuck recirclation and/or sparge.

I'm hesitant to tighten the gap much more but I may give it a shot too, again no real downside. I've also been pretty lazy with water to this point, sounds like it may be time to change that...

 

[iijakii]

Try a batch sparge or something just to see.

 

[ChocolateMaltyBalls]

Try a batch sparge or something just to see.

That's a good idea.

I don't expect the crush to change things much, you want to stay on the larger side anyway to help filtering. Are you recirculating your mash with the pump wide open? My first thought was fly sparging too fast, but since that's how you sparged before I'm leaning more toward water chemistry.

BTW what kind of grain bills have you used so far on the new system, any with a large %specialty grain?


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[hyperboarder]

Try a batch sparge or something just to see.

I've never once done this but I'm willing to give it a shot. I assume just add a bunch of water to the MLT after the mash, stir it up, and drain?

That's a good idea.

I don't expect the crush to change things much, you want to stay on the larger side anyway to help filtering. Are you recirculating your mash with the pump wide open? My first thought was fly sparging too fast, but since that's how you sparged before I'm leaning more toward water chemistry.

BTW what kind of grain bills have you used so far on the new system, any with a large %specialty grain?


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I've got a valve on the outlet of the pump to control flow, it's definitely not wide open, needs to be closed off a ways to avoid sticking. Grain bills have been fairly standard, primarily base malt, the KBS was the craziest with 25% specialty malt.