Not knowing what you're doing makes it difficult to say much about what you might be "doing wrong". A piece of general advice I've gleaned about all these systems is that it's a good idea to flush the lines during the process to avoid anything building up to the point where it blocks. This is generally just a case of running off a jug through the tap occasionally and doing the same through the recirc arm. Doing this during the boil is a good idea anyway to sanitise the line with boiling wort.
Brewzilla Gen 4 advice and experiences
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Not knowing what you're doing makes it difficult to say much about what you might be "doing wrong". A piece of general advice I've gleaned about all these systems is that it's a good idea to flush the lines during the process to avoid anything building up to the point where it blocks. This is generally just a case of running off a jug through the tap occasionally and doing the same through the recirc arm. Doing this during the boil is a good idea anyway to sanitise the line with boiling wort.
Difficult to say really are you sure that the tube connections are well made and not pinched in some way causing your problem. If you use the tap to transfer then there is a tubing connection modification that would be a help many people have done it as it does help if the pump gets blocked. Are you fitting the bottom filter plate properly?
I have done lots of brews and never had a problem with pump or tap. I would ask why you are using the tap to transfer the wort as pumping out through the reciculation arm is much easier.
So did my Brewzilla... what did I do right?
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But the argument for the defense of the BZ G4 has been the people who are struggling to come to terms with them don't know what they are doing, they have never used an AIO!
Didn't you cut your teeth on a Grainfather? This is a brewer going in blind as countless others do on other AIO's and we don't see anywhere near the posts of the problems that we see with the BZ G4.
peterpiper
Well-Known Member
The BZ G4, has a profile that is relatively tall and narrow compared to some other systems, though I don't know the exact height to diameter ratios of all the systems you've listed.
Grain bed compaction is always going to be a more likely issue in a tall narrow system like the BZ, than in a short wide one. Someone switching from a wider system, or following good advice meant for those, might be trying methods not suited to the BZ.
Since switching to a method to avoid grainbed compaction, based on G Wheeler's dough in advice, my BZ G4 is finally always working well.
I did get a replacement system (from Kegland). The initial one sent, had a poor fitting false bottom, with 2-3mm gaps in two places from the outer wall (due to tollerances & a slightly elliptical body).
Apparently the early design had a bottom (with two lift eyes), that was so tight fitting, it could be very difficult to remove. So they re-designed it for a looser fit, but perhaps too loose.
Maybe the poor fitting bottom, wouldnt have mattered to much. As to date, I've only found any grain on my false bottom in a single brew. And that was a stuck mash, where overflow including grain, went down the lift holes.
I don't recall seeing any of reports of a "blocked pump", where grain or flour was actually discovered inside the pump.
An airlock in the pump, from air or steam having been sucked in, can make it stop pumping. Usually just switching the pump off, and lifting the sparge hose up high will clear it. Sometimes removing the sparge arm, or blowing down the hose might be needed (same as BZ 3.1.1).
But even with the good fitting bottom, I initially had a few problem brews, many slow/ stuck mashes, and once a thick layer of burnt flour on heater (with an overheat shut down). That was after frequent stirring (of a wheat beer), needed to keep any mash recirculation going.
Target.
The grain bed itself is the real filter, not the malt pipe base or false bottom. When it's working, the grain bed will catch any circulating fine crush and flour. Bits that escape during dough in, are hopefully filtered out during recirculation.
Why stir?
If recirculating, and wort is already passing all the grain, stirring won't have much impact on efficiency.
If the grain bed becomes compacted, recirculation/malt pipe draining will be reduced or stuck. The stirring 'remedy', will disrupt proper grain bed filter action, even where husks etc are used.
Stirring can separates a load of the fine crush and flour, previously trapped in the grain bed. This can now escape with the recirculating malt, to maybe settle on the base, or in the pump, or get back to malt bed where it will form a top layer of mostly just the fine stuff - which will likely soon need stirring.
Solution.
After dough in you never want to stir! Avoid need to stir, by avoiding a compacted grain bed.
An uncompacted grainbed needs to stay 'floating' throughout mashing, so needs enough water for the grain to remain covered once fully hydrated.
Avoid a very stiff mash. A thinner mash might need a slightly longer mash time, but could end up much faster than a thick mash that gets stuck! For a 23l batch, I now use 20-23l strike water.
Roughly premix all the dry malts / husks / etc, as there's no mixing after dough in, but you want all coarse / fine / flour ingredients evenly distributed.
Add any wet ingredients after dough in, or gradually during dough in if there's a lot.
Wheeler's advice: At dough in, add grain to water gradually, with minimal stirring - just enough to break up any dough balls. This is to avoid knocking off the tiny air bubbles, attached to grain surfaces. These bubbles increase the grain buoyancy, so giving a more open (less compact bed).
Lowering a dry filled malt pipe, into the strike water, won't give that effect. As it enters the water, the full malt weight (grain weighing more in air than in water), is mostly being taken by the bottom layer of grain, making it more compact.
DON'T use the the top plate while mashing. It's extra weight, makes bed compaction more likely. Providing there's a layer of wort covering the grain, that alone, will distribute recirculating wort evenly.
(Add top plate for sparge, but not till after draining).
After dough in, allow a grain bed rest of 15-20min, for the grain to hydrate and the bed to stabilise.
The grain bed hopefully has the all coarse / fines / flour parts fairly evenly distributed, and once hydrated, imagine these being loosely locked together.
Then recirculate at a slow rate for 10min.
Then increase rate to highest possible flow, while keeping wort level rise (in malt pipe) to less than around 2cm. Any more and the differential pressure, due to difference in liquid levels, can cause compaction. The most extreme differential case, is where there's air under the malt pipe.
From start of dough in, and during the grain bed rest, I do 'outer recirculation' at max flow. With the sparge hose stuck down a malt pipe lift hole, so flow runs outside the malt pipe. This stops the wort temperature dropping too much over the rest, and helps keep any flour that falls from pipe at dough in, in circulation. Rather than it settling out on the heater (and scorching later). Any circulating flour, will be caught in the grain bed, when normal recirculation starts.
For a fast drain while sparging, maintain the uncompacted grain bed when lifting the malt pipe.
Try to lift it slowly, so grain bed base isnt compacted by a sudden lift, causing a large weight of grain + wort above. Lift gradually, so wort visible in pipe stays no more than around 5cm above the surrounding wort level. Continue lifting at same speed, once wort is no longer visible, and leave pipe in half lifted position, till wort stops draining.
Following that method, same recipies that previously always failed in my BZ G4, now always work. And I don't need the two bags I'd ordered in desperation!
Care is more important, for recipes with a large grain bill, or more flour (fine crush or high % wheat grain).
Mr & Mrs Smith
Active Member
Yes, I have read all the posts here Peter, you weren't alone in trying to get a satisfying result. Bags which IMO are part of the answer, one welded 25cm spacers to the bottom of the malt pipe. I didn't know Graham Wheeler had a BrewZilla G4.
I tend to go with the real experts, read Crisp's advice on mashing dough in, and gently stir as one is doughing in. This should be for about 15 to 20 minutes.
A read every home brewer should read is Brewing Science and Practice, a mash which is more fluid will improve efficiency. The crush If the crush, is too coarse the pieces of endosperm will be too large for the gelatinization and enzymes to convert them at the chosen saccharification temperature and time. (Briggs)
Don't be afraid to use a paddle you can always carry out a 20-minute vorlauf to make sure no small particles are going into the boil.
Pleased you have come to terms with your method of using the BrewZilla G4 and are coping well. You certainly had a roller coaster ride for a while there. And yes width of an AIO is important both for temperature control and ease of wort permeating through the grain bed.
I was thinking earlier that when I did BIAB in my Burco boiler the tap got clogged every time I brewed. Even with one of those torpedo mesh things attached. I always used leaf hops straight into the boiler. At no point did I think that either I or the boiler was at fault. It was just what happened and I dealt with it.
Do other AIOs have the emptying hole at the bottom at the neck of a funnel shape ? Wondering if this can increase the probability of clogging ?
Hi Peter, thanks for the tips yesterdays brew went much better without any blocked pump or tap or stuck mash, which have been a regular thing for me.
One other result of switching from 56l electric BIAB to GF S40 is that the water loss is much lower.
Yesterdays brew was a pale using 200g home grow leaf hops and 4kg MO and 200g crystal with Brewfather predicting 32.5l of water and a target 23l in the fermenter with OG 1.044 (4.3% but me expecting closer to 4).
I've actually got a very clear 26.5l with an OG of 1.032 that smells pretty good.
I've been seeing a pattern of far less water loss than predicted but this is meaning I'm going to have to knock 3l off the water volume for future brews.
Does this result seem in keeping with what the collective would expect?
also does anyone have any thoughts on how best to adjust the ABV closer to 4% as the wort is at 28C and I pondering adding sugar or changing the CML Midland to a different yeast e.g. Saison?
Any thoughts welcome :-)
I set a boil off rate of 2.5l per hour on my bz gen 4 which is lower than the "stock profile" from brewfather, but @Baldylocks Brewery it sounds from your post that you are using a Grainfather S40 so not sure how useful this is to you
Sorry Tondy, I'm currently BZ G4 and those are the prior systems with much wider diameter openings.
Good to know what boil off you are using
I'd add a bit of sugar. Roughly 2.5g per point per litre. To get to 1.040 from 1.032 you'd need 8 X 2.5 X 26.5 = 530g (mental maths so will need checking).
Thanks 2Stage I’ll do that
peterpiper
Well-Known Member
Glad you've having success.
Was that in a BZ G4, or a GF?
23l OG 1.044, I think, would become an OG of 1.038 if diluted to 26.5l
Is coming in under gravity, an issue for you?
I finding the BZ G4 often achieves a higher OG than predicted by Brewfather.
That's been when controlling temperature using the RAPT probe (I've not yet got accurate measurements for non-RAPT).
A tall narrow profile, increases the likely temperature difference between top of malt pipe and in the base.
On a cold day, and where only slow mash recirculation is possible, the BZ G4 (neoprene jacket) can record a 10°C difference for long periods, between the built in probe and RAPT readings. Particularly noticable when doing a temperature step mash.
Which reading should be 'right'?
The 'differential override' setting, limits the base temp overshoot when using RAPT control. But the lower this setting (and the slower the recirculation), the longer it takes top of malt, to reach the desired temperature.
The balance, of fermentable to unfermentable sugars, is likely to be very different, at very different temperatures. I've had the choice: 10°C low at top (for normal period), vs 10°C high at base (for the extra 20 minutes it takes for top to reach the 'right' temperature).
I'm starting to believe, that waiting for the the top temperature to reach the required value (ie RAPT controlled), for the full time, doesn't produce the beer expected. Generally too full bodied, due to unfermentables.
For lighter style beers, I'm preferring those it produces when mashing using bottom sensor temp control (rather than RAPT). I'd like to use RAPT all the time, so maybe need to tweek the brew profile.
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peterpiper
Well-Known Member
He didn't mention using one!
Another Crisp article 'oats-in-brewing', covers the maths of grainbed differential pressure & compaction.
Grain crush solved most of the issues I had initially with by BZ4. I remember the fun with blockages the first time I used it but I'd bought an all-grain kit from the local shop for handiness to give it a go and it was basically a bag of dust. Even the next few where I crushed myself with the same settings as for my G30 were too fine for this.
I take half an hour to condition my grain now and crush on the large side and I can walk away from any mash now and end up with a nice clean boil.
I take half an hour to condition my grain now and crush on the large side and I can walk away from any mash now and end up with a nice clean boil.
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Have you seen the thread about conditioning?
No I don't think I've come across it on here. I find it great for easy mash-in too.
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A good read here. Grain crush, and going for a coarse crush leaves about 7% of the grain uncracked leading to a drop in efficiency but most programs account for this. Crushing your grain allows you to take up the slack.
https://byo.com/article/the-perfect-crush/
I'd be hitting about 78% mash eff with what I'm doing now but with none of the other hassles that come with too much grain getting through the basket. I'd say I could probably get more (I think I had about 85% on the G30) but I don't mind so long as it's predictable.
Maybe I'm not overly coarse now, it's more coarse than it was (setting 6 on the GF mill currently) but i find the conditioning leaves them more nicely cracked overall and not obliterated - lets me run the recirc near max too.
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I run my system with the top and bottom sieve plates together at the bottom, my next brew I will be trying a fine sieve between the the two plates so I can mill even finer and get more bang for my buck. I'm not sure how it will go as being dependent on gravity may not work. But I will never know if I don't try.
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