Low efficiency problem

[kohalajohn]

Don't forget you can use the controller parameter called "Allowed Sensor Differential" to limit how much hotter you'll allow the wort to get heated above the blutooth thermo setpoint. Just set that to something like 3F so that it can't heat hotter than setpoint+3.

Done. And the PID is set up.

And what hungup and tracer said, about involving the dead space between the two walls, today I saw that clearly.

Twenty minutes into the mash I directed the outlet hose into the lifting hole, forcing the dead wort between the walls, to join the rest of the wort.

I took OG immediately before doing this, and again immediately after. I"m glad I did. What was fascinating, is that the OG dropped a few points.

Meaning that yes, that wort in between the walls was not circulating through the mash, was not picking up sugars, and was at a lower OG as a result. When I made it join the rest of the wort, the entire wort's OG dropped.

 

[Yooper]

Don't forget you can use the controller parameter called "Allowed Sensor Differential" to limit how much hotter you'll allow the wort to get heated above the blutooth thermo setpoint. Just set that to something like 3F so that it can't heat hotter than setpoint+3.

I've done that- still not thrilled with it and I'm happy enough to do it without the rapt thermometer.

 

[hungupdown]

Morning all

Just had a very low efficiency problem in my Brewzilla G4 35l. Suspect the problem is with the recirculation hose but am asking here first.


Belgian Blonde recipe predicted OG 69 and I only got OG 40.

6.5kg malt and also 500grams cane sugar at end of boil. Four gallon brew.

Did full volume mash, starting with 25 liters. Strike 154F and mash at 150F for 90 minutes, then 170F mash out.

This is my second brew with this machine. When I laid in the silicone ½ ID hose into the mash for recirculation, I worried that the hose was short. I’d prefer a long hose that lay in a flat circle around the top of the mash, gently pouring out hot wort horizontally, while underwater.

I couldn’t see the hose, but I worried that it may poke into the bed and channel.

Sure enough when I lifted it up, the mash was piled up high on one side. And a lot of grain had been pushed down through the false bottom. In fact it jammed the recirc hose such that I had to drain out the bottom to get it to work.

And there was that disappointing OG 40.

Would this device help:

Mash Recirculation Return and/or Sparge Kit (locline)

Or this:

Mash Recirculation Add On Sparge Ring (locline)



Another reason for the problem may be too much mash water. I do four gallon batches. I had wort left over when I filled my fermenter vessel. So that doesn't help

Or it could be something else I haven’t thought of.

As usual, your thoughts appreciated.

I generally do a thin mash, where mash water about batch volume. So maybe 23L + 8L sparge.
With a thin mash, the grains are covered in liquid, so there is no need to disperse the sparge. I position the recirc hose about 1/2 inch over the wort, then reduce flow if wort level rises to near hose.
I only use the rop plate for sparging. Never for mash, as the extra weight adds to chances if a compacted grain bed, which are already high for the BZ because of its relatively tall narrow profile.

For the same reason, lifting the malt pipe to mix in the surrounding unused water, is also very likely to compact the grain bed. And is why some brewerieries do a 'floating sparge'.

A much better way to utilise this water and increase effeciency, without risk, is to do 'outer recirculation'
You simply need to run the recirc hose, through one of the lift arm holes, for a couple of minutes. Maybe three of four times, during the mash.
I do that continuosly, at full flow rate, which stops flour and fine particles settling out on base, and gives much improved temperature control. I have a second hose connected to the (pumped) drain tap for recirc through the grain bed, with flow controlled by the grain tap.


Half my brews use 6.6 - 6.9kg, some 50% wheat, without problem.
In early days, before I'd mastered the system (and cut out most stirring). I did a 25L batch of 6.6% Weizenbock by mistake. As I'd forgotten to scale it to 23L.
OG ended up at 1.070, which was above the target. But had temporary overheat shutdown during boil, sensor showing 115°C. Found the whole gap below HED, was full (apart from a few channels) of scorched flour. Leading to an excessively smoked flavour.
Nearly went down the drain, but managed to find someone who liked it.

For grains to get below the false bottom:
Either- you have a badly fitting malt pipe base, or had an overflow (via the lift holes) AND have a badly fitting false bottom.
Or- you switched the pump off, when the hose was below the surface and the valve wasn't closed. Leading to back syphoning.

My initial G4 had a very loosely fitting false bottom, with a gap of 2mm around much of the circumference. I was worried thst leaf hops could slip through, though it wouldn't have let whole grains pass. The loose fit was due to the boiler body being oval shaped, rather than round.
The supplier eventually sent me replacement parts, with a much better fit.

I'd say, do at least a small sparge. As slowly as possible (to allow sugars time to diffuse from within grain). With either slightly reduced mash water, or a longer boil. Leaving drained malt pipe in bucket, for most of boil time, to collect final drops for late addition.

I had to pause a recent 30L batch (using boil extension), for 5 hours. So left it doing a 'floating sparge', malt pipe in bucket, with the 15L of sparge water poured through (and just about covering the grain). Preboil gravity, ended up much higher than expected. I measured 1.042 in about 32L. From 4930g grain.
Someone did the calculations for me, and said that was 89% efficiency.(I think brewfathers figure for the BZ g4 is 76%).

 

[Halfakneecap]

I never use the top plate in my robo, never had any issues. I don't use the fine bottom screen either with no issues.

I've also removed the centre overflow pipe, and plugged the hole. Next batch is my 100th in my robo so i'm pretty comfortable with it now.

Hopefully not confusing the issue, just adding data points which may or may not be helpful.

 

[tracer bullet]

Regarding sparging, I've been skipping it as well. I did it without fail on my propane setup, it was ingrained for me as a process step for decades. Slowly with the AIO tried skipping it and it's been fine. I squeeze the grains pretty well and there's very little left. Sparging gets me a few % points efficiency but no even 5% and so I've just started to account for it with like a half pound more base grain. I don't mind saving the work. I only do it now with imperial stouts where I push the limits on the grain to start with, and want all that I can from it, and already planned a really long boil anyhow. for "normal" beers I save that work and have no regrets.

 

[sibelman]

monitoring the mash wort's gravity as it rises and plateaus during the mash

mash until SG plateaus.

Thank you, gentlemen.

In the past I've only used the clock (one hour was the magic number) and iodine test. Today, I went to 80 minutes, when plateau occurred. Gravity went up ~.002 during the "extra" 20 minutes.