Brewzilla Temp problem

[Mash Monster]

I agree I have also been using a SS strainer but it keeps floating off so I have just ordered a GF Overflow filter from the MM.
I will report back after I’ve tried it

 

[Hop_it]

Hmmm fiendish . . . . . I've not seen that before.
I have used a teapot strainer, and it has never come off. But a few days ago I decided to develop the idea further. I already had a sheet of SS mesh, so I have wrapped a piece of it around the removable top section (with the internal taper), and clamped it in place with a SS Jubilee clip. I haven't tested it yet, but I'll probably be brewing again soon, so I'll give it a go

 

[Mash Monster]

Thanks MM. I had no idea there was a V2 false bottom. Great photos. I see what you mean, they may be trying to get the trub away from the holes. Can you let us know if this fixes the temp problem? I too wondered why they let the false bottom touch the tap, which seems a pretty poor design, which does not let the false bottom sit horizontal. I will have a measure up and see if I can add some SS screws to the bottom of the legs which at least lifts it up a bit. In the meantime I will bash on with 2 more brews without the bottom plate. If I get any burnt flavour then I will know I need it. If not then one less item to wash up ;-)

Hi Phil a quick update re the V2 false bottom I used it in a brew today and it made a big difference Temps were within 1°c and because it is slightly bigger it is a snug fit and didn’t move around during the boil. However I did use the fine mesh (unintentionally) and the Grainfather overflow filter combined.No stuck sparge no stuck mash and no blocked pump. Not all good though I missed my OG by 3 points Something that’s never happened to me before ! Ah well something else to worry about !

 

[J P]

This temperature issue happened to me today. Second time it’s happened. Seemed to find an easy fix!

I have a thermometer in line on the recirc pipe. Brewzilla reading 72c. Wort was 60 to 62c.

Recirculate wort straight down the centre pipe. The reading on Brewzilla dropped straight away. Element came on. Slowed the recirc down and it was fine for the rest of the mash.

This is a Porter will rolled barley and whilst recirc seemed to be ok a quite quick. I think there was not enough wort below the mash pipe.

Will be interesting to see if my final gravity is low as the mash was in the low 60s for about 20 mins while I faffed about stirring and reciting etc!

 

[Rodcx500z]

This temperature issue happened to me today. Second time it’s happened. Seemed to find an easy fix!

I have a thermometer in line on the recirc pipe. Brewzilla reading 72c. Wort was 60 to 62c.

Recirculate wort straight down the centre pipe. The reading on Brewzilla dropped straight away. Element came on. Slowed the recirc down and it was fine for the rest of the mash.

This is a Porter will rolled barley and whilst recirc seemed to be ok a quite quick. I think there was not enough wort below the mash pipe.

Will be interesting to see if my final gravity is low as the mash was in the low 60s for about 20 mins while I faffed about stirring and reciting etc!

I can't or don't understand recirculating down the overflow pipe, the whole point is to recirculate through the grains, i see your point but the recirculated wort is not going back through the mash and is likely to be dryer than it should, all you are doing is pumping from bottom to top

 

[Agentgonzo]

I can't or don't understand recirculating down the overflow pipe, the whole point is to recirculate through the grains, i see your point but the recirculated wort is not going back through the mash and is likely to be dryer than it should, all you are doing is pumping from bottom to top

The overflow pipe is there as a safety measure only. If you get a stuck mash, but are still pumping wort from the bottom of the vessel to the grain bed, then without an overflow pipe, you'll end up without any wort at the bottom of the vessel and you'll burn your element.

You want wort to go back down through the grain.

It's like the overflow on your sink. Under normal circumstances, you want the water going down the plughole, but if for some reason that gets clogged and your tap is still running, you need the overflow to save you from an accident

 

[J P]

I can't or don't understand recirculating down the overflow pipe, the whole point is to recirculate through the grains, i see your point but the recirculated wort is not going back through the mash and is likely to be dryer than it should, all you are doing is pumping from bottom to top

I don’t recirculate through the pipe. Just pumped some wort down it when the temperature reading was off. I think this displaced a pocket of air that had formed and then set it back to normal.

I usually keep recirc so it’s 2 cm above the top plate and not running down the pipe.

 

[hoppyscotty]

Hmmm fiendish . . . . . I've not seen that before.
I have used a teapot strainer, and it has never come off. But a few days ago I decided to develop the idea further. I already had a sheet of SS mesh, so I have wrapped a piece of it around the removable top section (with the internal taper), and clamped it in place with a SS Jubilee clip. I haven't tested it yet, but I'll probably be brewing again soon, so I'll give it a go

View attachment 42431

This is exactly my solution to this problem...well improvement at lease. I'm convinced overflow is needed. Unless you have the flow through the malt column and recirculation flow perfect then there are several potential issues. By running some slightly cooler overflow you ensure wort from the top is flowing down to the bottom and any variations in flow that allows warmed wort to stagnate at the bottom prevents heat build up with the rather rudimentary thermostatic system struggles to respond to.

I push this down to enable some overflow and this seems to improve the situation and I get far better temp control than I did previously with few runaway temp increase events. Still not perfect, but an improvement.

Also in the BZ instructions it Does say not to run both elements while the malt pipe is in place. Not sure this is a contributory factor but I now heat up strike water a few degrees warmer with the malt pipe removed, and add the malt pipe just before roughing in and only run one of the elements during the mash. Keep meaning to try underletting to see if this makes a difference.

Also I've learned to not sweat it or panic. I used to manually intervene when I had a runaway temperature event but you just make things worse, if you just leave it, it normally sorts itself out as quickly as it kicked off...I'm not even sure its reading correctly when this happens, I'd be amazed if it can suddenly add 10 degrees or so of temp in such a short space of time, I can never get that performance when bringing to the boil, so suspect its a glitch in the control system and its giving a false reading....but I've not confirmed that.

Anyway thats my hypothesis anyway.

 

[Little Rock Brewing]

I love this forum!
I've exactly the same problem on my last 2 brewdays. Seemingly stuck mash and temperature sky high, but the wort temp way too low.
Coincidentaly I was also trying a stepped mash at 40, 50, 60 and 70C and I think the low starting temp of the mash was causing it to become stuck.
All I could think to do was dial up the temp to 90C and let it gradually rise using the 500W element. Every time I tried to 1900W one it gave me the E3 error code.
As the temp slowly rose, the mash started flowing better and better and cleared nicely.
All in all it took nearly 3 hours for the mash, but the efficiency was incredible!
I ended up with nearly 25 litres from a supposed 20 litre AG kit at the recipe's quoted 1.060 OG.
I'll certainly get the V2 bottom plate to help the situation but I'll also probably start the next step mash at the high 40s.

 

[Agentgonzo]

I love this forum!
I've exactly the same problem on my last 2 brewdays. Seemingly stuck mash and temperature sky high, but the wort temp way too low.
Coincidentaly I was also trying a stepped mash at 40, 50, 60 and 70C and I think the low starting temp of the mash was causing it to become stuck.
All I could think to do was dial up the temp to 90C and let it gradually rise using the 500W element. Every time I tried to 1900W one it gave me the E3 error code.
As the temp slowly rose, the mash started flowing better and better and cleared nicely.
All in all it took nearly 3 hours for the mash, but the efficiency was incredible!
I ended up with nearly 25 litres from a supposed 20 litre AG kit at the recipe's quoted 1.060 OG.
I'll certainly get the V2 bottom plate to help the situation but I'll also probably start the next step mash at the high 40s.

I use a grainfather, but it's basically the same mechanics as the brewzilla. I now always stir the mash after about 5, then 10 minutes. It really loosens up the grain basket/malt pipe and after that I get a really free running recirculation. Without the stir, recirculation is really really slow

https://www.thehomebrewforum.co.uk/threads/question-for-brewzilla-owners.100278/post-1170434

 

[Little Rock Brewing]

I do stir a lot as I find a huge variation in temp through the mash, plus I'm a fiddler!
Out of interest is a stepped mash just a way of getting better efficiency, or are there flavour benefits too?

 

[hoppyscotty]

I tried step mashing as a way to try to fix attenuation problems. I was consistently finishing a few points too high despite hitting OG, so I tried a step at 63 degrees for 20 mins then rise to 67 degrees or so for the remainder of the mash in an attempt to better control the proportion of fermentable vs non-fermentable, with the step up denaturing the Beta amalayse enzymes. Didn't work. Turned out my cheap eBay hydrometer was reading 4 points high. Changed the hydrometer and hey presto...was suddenly hitting FG and attenuation!!

My understanding of stepped mashing is it is a thing of the past when grains were not malted or the malting process was not as sophisticated as it is today so largely unnecessary unless you're brewing with some unmalted specialty grains or something.

 

[hcallahan]

Hi! It seems I have the same problem with 3.1.1 since I'm using it.
With pure water the temp sensor is working fine, max 1-2C difference. When mashing, it had 5-15C difference, usually.
I measure the wort temperature in the middle with a kitchen thermometer, and also some wort let out in a mug.

Yesterday I started brewing in the shadow, and when the sun started to shine on the back of the machine, the sensor showed me 80-90C (while the mash had a 40-45C!!!!) Then for some time the display run into ERR.
When I moved the whole stuff into the shadow, the temperatue difference got back to 15C (50C mash, 65 shows the display)

Now I use the brewzilla in full manual mode: set the temperature to 99C and manuall turn on and off, stiring the mash with a spoon.
However, I think this should not be the way

I think there is some heat conduction / insulation problem around the temperature sensor, as the wort itself is much cooler around it.
Maybe, the sensor should be pulled up a bit (1-2cm) from the bottom.

 

[hoppyscotty]

Hi! It seems I have the same problem with 3.1.1 since I'm using it.
With pure water the temp sensor is working fine, max 1-2C difference. When mashing, it had 5-15C difference, usually.
I measure the wort temperature in the middle with a kitchen thermometer, and also some wort let out in a mug.

Yesterday I started brewing in the shadow, and when the sun started to shine on the back of the machine, the sensor showed me 80-90C (while the mash had a 40-45C!!!!) Then for some time the display run into ERR.
When I moved the whole stuff into the shadow, the temperatue difference got back to 15C (50C mash, 65 shows the display)

Now I use the brewzilla in full manual mode: set the temperature to 99C and manuall turn on and off, stiring the mash with a spoon.
However, I think this should not be the way

I think there is some heat conduction / insulation problem around the temperature sensor, as the wort itself is much cooler around it.
Maybe, the sensor should be pulled up a bit (1-2cm) from the bottom.

Are you running an overflow during circulation? I'm convinced some overflow is intended as a fundamental part of the design of this system to ensure some flow/agidation of the wort in the space under the mash pipe. Even with a small recircurculationa flow from the pump you are still getting some areas of stagnation in that area that probably allows 'clouds' of warm wort to form. If one of those clouds happens to move over the thermometer then you get an instant increase in measured temperature, if not then that area could overheat and scorch the bottom plate and impact the enzymatic behaviour.

By running some level of overflow you are ensuring you are constantly disturbing the wort volume under the Malt pipe and therefore get a more even temp in that area and throughout the mash. I certainly get more stable mash temp control when running some overflow...still get a difference between the bottom and top of the vessel, but at least I'm not getting temp swings.

You can see this in the design of the new Grainfather G4 that has done away with the central overflow tube, but replaced it with columns of perforations running up the height of the malt pipe to ensure flow from the top of the malt pipe and around and under the malt pipe. And of course the Clawhammer system uses a mesh basket.

I think I saw a video with Kee from Kegland saying he was considering this design for a future mod for the BZ Gen 4 also....and since the launch of the BZ Gen 4 some people have complained about lack of temp control and they've released the false bottom with the diversion plate, which seems to me to promote a flow of wort under the malt pipe and across the heat plate and prevent wort stagnation.

 

[MrJay83]

I've been experimenting over my last few brews with the flow from the recirculation. All the way from having it almost full on with wort going down the overflow (seen David Heath do this a lot in his videos) to having it barely trickling. For my 3.1.1 the mash definitely does seem to go a lot better (temperature stability-wise) with the flow fairly restricted.
One thing that happened for the first time on my last brew... I was chilling the wort down to 22C (20C was my pitching temp but I brew outdoors so give a bit of margin) and all was going good. Hit my temp, transferred, put the lid on, into the chamber and when I looked at my Rapt controller it was showing 13.5C on the pill & 13C on the probe. I don't believe I could have possibly lost 8C+ in the time it took from when the transfer started to putting it in the chamber. 2-4C, yeah but not that much.

 

[MrJay83]

I think I saw a video with Kee from Kegland saying he was considering this design for a future mod for the BZ Gen 4 also....and since the launch of the BZ Gen 4 some people have complained about lack of temp control and they've released the false bottom with the diversion plate, which seems to me to promote a flow of wort under the malt pipe and across the heat plate and prevent wort stagnation.

I believe that's probably more to do with the drain being dead centre and this new plate makes the wort pass equally over the elements in an even distribution. I'll bet that it previously was pulling a lot of it straight from the malt pipe centrally and not passing over the elements.

 

[peterpiper]

Temperature overshoots will always be greater, and last for longer, as the circulation rate is reduced. Overshoots become smaller, and shorter, with increased circulation.
Recipes with a high % of wheat or rye malts, often have a reduced maximum grainbed flow rate.

With the BZ3.1.1, any increased recirculation, from flow via the overflow pipe, largely travels over the heater and sensor, so helping to reducing overshoots.

The height of the overflow limits the differential pressure (from diference in liquid levels) on the grain bed. A pump flow rate, faster than the grainbed flow, will eventualy drain wort level to below the malt pipe. This can result in a compressed grain bed / stuck mash.

In he BZ g4, the only overflow path is via the lifting holes. Being higher (than g3 overflow), an overflow here will have a higher (than BZ3.1.1) differential pressure.

In BZ g4, as supplied, flow through the malt can mostly bypass the temperature sensor and heat plates. The HED dish option, that forces all flow via the outer edge, is designed to solve this issue.

I now always mash, with maximum recirculation, at full pump flow rate (BZ g4), having added a second recirculation pipe (from drain tap). This splits the flow, between maximum possible via grain bed, and the rest flowing outside the malt pipe (via pipe, stuck down a lift hole).