Low efficiency problem

[kohalajohn]

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.

 

[tracer bullet]

In the Anvil Foundry world, "we" have a lift and lower thing. A couple times while mashing (2 or 3 over the hour) it's advisable to lift the basket, allow all that water on the side of the basket to mix in, and then lower the basket again afterward of course. It's fine to stir the grain in the basket as well. It's surprising but even with just an inch or whatever all around the basket that's like 30% of the useable volume (cross section) that's basically pure water. It pays to mix that in a couple times.

 

[kohalajohn]

Makes sense, and easy to do.

 

[kohalajohn]

Tracer, does your Anvil have a recirculating pump?

Mine does. And in theory the recirc should blend all the water together.

But in online research, I think that during the mash I should turn it down to slow. At full speed I think it just channelled through the mash without accomplishing a full water infusion.

Just theory. but next time I'll run the recirc very slowly. It's going on for an hour, so I don't see any need for speed.

 

[tracer bullet]

Tracer, does your Anvil have a recirculating pump?

Yes but it pours into the inner part of the basket. The outside is still not mixed in. Thus the lift & lower technique.

Alternately put a round grill thing in the bottom and use a bag, skipping the pipe altogether.

https://www.amazon.com/dp/B07G1B1YJM?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_4&th=1

 

[sibelman]

All of the above, plus: the crush of the malt can considerably affect efficiency. A finer grind could help.

 

[hungupdown]

In the Anvil Foundry world, "we" have a lift and lower thing. A couple times while mashing (2 or 3 over the hour) it's advisable to lift the basket, allow all that water on the side of the basket to mix in, and then lower the basket again afterward of course. It's fine to stir the grain in the basket as well. It's surprising but even with just an inch or whatever all around the basket that's like 30% of the useable volume (cross section) that's basically pure water. It pays to mix that in a couple times.

Mixing in the water outside the maltpipe, can only increase mash efficiency.
But with the Brewzilla G4 35l (and the BZ 3.1.1) tall narrow profile, lifting the maltpipe, is more likely to compact the grain bed. Especially with sticky grains, or high grain bills.

You're much better using 'outer recirculation', to utilise that water without lifting the malt pipe. Just poke the recirc hose through one of the malt pipe lift holes, then run at full flow, two or three times while mashing. Outer recirculation, during initial 10-15minute grain bed rest (bef recirculating through the malt), helps stops the malt cooling during the rest.

A recirculation mod, with 2nd recirculation pipe off the (pumped) G4 drain tap. Let's me do outer recirculation using original hose, at full flow, throughout mash. While the extra hose does recirc through the grain, flow being controlled by drain tap..

 

[hungupdown]

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

By "full volume mash", do you mean you didn't do any sparge? No sparge would reduce efficiency.

I get good efficiency in my BZ g4, using strike water = batch volume (usually 23L) Then sparge with 9L or so.

 

[tracer bullet]

You're much better using 'outer recirculation'

Should work as well. I mentioned stirring afterwards to redistribute the grains. I used to be adamant about them making a bed, for filtering, and so on but really no longer think hat matters. And if it does I've still normally left things along for 10-15 minutes between the last lift / lower / stir time vs me actually mashing out and removing the grain altogether.

 

[kohalajohn]

Interesting.

Although they say only change one variable, I think from this that there are several improvements to be made.

First, I'll go back to sparging. In my first attempt, when I pulled it up to the halfway point, I gave it a cold water pour over. Three gentle pours from a two liter jug. I think I'll return to that. It's not fly sparging, but a pour over sure works for coffee.

My next brew will be a 15 liter czech lager. I'll check the program, but something like 15 liters strike water and 6 liters cold pour over.

Second, I was like Tracer, obsessed with a tight filter bed and preventing the least amount of evil grist into the boil. I see now that the more important issue is to stir and get that damn sugar away from the grits and into solution.

Third, while the recirc tube is resting on the bed, I'll turn the recirc flow down to gentle. No need for a high speed flow.

Looking forward to it.

 

[tracer bullet]

Yeah, you'll get a few more brews in and before long will have your technique perfected.

 

[DuncB]

DON'T lift and lower the grain basket in a brewzilla, unlike the anvil the bottom is removable and you can displace the bottom up and grains fall out.

It might work if you did it really slowly but then you wouldn't get that dead space mix.

If you immerse the recirc tube in the grains when the pump turns off it will suck grains back into the tube / pump and block it, unless you are using the top plate.

6.5kg is quite a big grain bill for the brewzilla 35 and so efficiency will be down, also no sparge is a reduction.

Worth moving this to the Brewzilla 4 thread, you can read all of the woes there and some solutions.

39 healthy pages to read.

https://www.homebrewtalk.com/threads/brewzilla-gen4-discussion-tips-talk.702436/

 

[Whisky River]

DON'T lift and lower the grain basket in a brewzilla, unlike the anvil the bottom is removable and you can displace the bottom up and grains fall out.

It might work if you did it really slowly but then you wouldn't get that dead space mix.

If you immerse the recirc tube in the grains when the pump turns off it will suck grains back into the tube / pump and block it, unless you are using the top plate.

6.5kg is quite a big grain bill for the brewzilla 35 and so efficiency will be down, also no sparge is a reduction.

Worth moving this to the Brewzilla 4 thread, you can read all of the woes there and some solutions.

39 healthy pages to read.

https://www.homebrewtalk.com/threads/brewzilla-gen4-discussion-tips-talk.702436/

I’m not going to weigh in on the mash pipe lifting issue other than to say I think some people have had positive results and some have had problems. But my understanding is that 6.5kg is equal to about 14.3lbs which I think is right in the middle of the 23.5lb capacity of the Gen 4 Brewzilla 35 so my guess is that the problem lies elsewhere.

Like so many of these issues I suspect it’s probably a combination of things, but I’ve never heard of anyone running their recirculation at full throttle before. I think the recommended rate is something like 2 liters per minute which is pretty slow (double check that though).
I’m also not sure how the end of the recirculation hose could get buried in the grain if you were using the top plate, which is specifically designed to prevent that. You also didn’t mention if you are using the HED which was also designed to prevent the recirculation from channeling straight down the center drain.
You also seem to be running at around 4 l/kg which seems a bit thin for a traditional system. That might be fine for a full volume biab mash but I think most AIO users go with a significantly thicker mash.

It seems like you’re trying to add a bunch of innovations to your process right out of the gate, which is fine but you might want to try using your system as it was intended first before you start altering the process to much. That way you have a baseline to work from so you can identify the causes of any problems that arise.

Good luck getting your numbers back on track and enjoy the Blond, I bet it will turn out great regardless.

 

[Bobby_M]

but I think most AIO users go with a significantly thicker mash

Most AIO users are forced to sparge because they can't fit it all, not because it's objectively better.

 

[Bobby_M]

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

What efficiency did that recipe assume?

 

[Halfakneecap]

I have a 35l robo and 6.5kg is a lot IMHO. I have the extension malt pipe for double batches, and would use that for the rare High OG batch i brew.

I have also used a BIAB bag for higher gravity batches before i got the extension malt pipe.

Also, once the mash recirc has started, i turn the flow right down. I use a peg, and hold the hose on the side. It hits the side of the malt pipe, with no issues.

 

[Whisky River]

Most AIO users are forced to sparge because they can't fit it all, not because it's objectively better.

Agreed. I’m not saying it’s inherently better and I probably wasn’t particularly clear in my last post. I was just trying to point out where OP was departing from how his system was designed or traditionally used.

I’m wondering if what is happening to the OP is that the recirculating wort is blasting right through the grain and out the center drain. If he’s not using the top diffuser plate, has the recirculation hose pointed straight down into the grain, doesn’t have the HED plate, and is running his pump at full speed, it seems possible that he’s running a jet of wort right through the grain. Idk if a thick or thin mash would affect that at all, I just thought it might be one possibility.

 

[kohalajohn]

I’m not going to weigh in on the mash pipe lifting issue other than to say I think some people have had positive results and some have had problems. But my understanding is that 6.5kg is equal to about 14.3lbs which I think is right in the middle of the 23.5lb capacity of the Gen 4 Brewzilla 35 so my guess is that the problem lies elsewhere.

Like so many of these issues I suspect it’s probably a combination of things, but I’ve never heard of anyone running their recirculation at full throttle before. I think the recommended rate is something like 2 liters per minute which is pretty slow (double check that though).
I’m also not sure how the end of the recirculation hose could get buried in the grain if you were using the top plate, which is specifically designed to prevent that. You also didn’t mention if you are using the HED which was also designed to prevent the recirculation from channeling straight down the center drain.
You also seem to be running at around 4 l/kg which seems a bit thin for a traditional system. That might be fine for a full volume biab mash but I think most AIO users go with a significantly thicker mash.

It seems like you’re trying to add a bunch of innovations to your process right out of the gate, which is fine but you might want to try using your system as it was intended first before you start altering the process to much. That way you have a baseline to work from so you can identify the causes of any problems that arise.

Good luck getting your numbers back on track and enjoy the Blond, I bet it will turn out great regardless.

Whisky, first I'm glad you spell your first name without an "e"

Second, about the top plate. No, I did not use it. I was talked out of it by various you tubes.

I think I'll try the plate next time. I have soft silicone 1/2 id hose lying on top of the bed and next time it will be flowing very gently. And all underwater, hopefully.

 

[Bobby_M]

I would not recommend sparging to try to fix this problem just because it's absolutely not why the efficiency is some 40% lower than it should be. A sparge on an AIO is maybe worth an extra 5% like the difference between 70 and 75%.

If I'm doing the math right, OP got about 28% brewhouse efficiency which means almost everything went wrong.

Here's the priority of troubleshooting in my opinion:
1. What does the crush look like? With those numbers, I'd wager most of the grain wasn't even cracked open.
2. With a visual inspection that the grain is all adequately cracked, move on to monitoring the mash wort's gravity as it rises and plateaus during the mash.

6.5kg is 14.3 LBs (sorry I'm still trying to think metric but can't). At a reasonable 70% mash efficiency, the preboil/mash liquor gravity should reach 1.070. That's even before boil concentration and the 500g of sugar added.
Even a dismal mash efficiency of 50% would get your mash liquor gravity to 1.050 at the end of the mash.

In other words, you were barely mashing.

The recirculation rate, diffusion method and all that can't have a 40% degradation of efficiency.

 

[kohalajohn]

What efficiency did that recipe assume?

It didn't say.

Frankly, I'm still looking around for where to find stated maximal efficiencies. I have not seen this in stated recipes yet. When I see someone say they hit 75% efficiency I think, well, 75% of what?

 

[mac_1103]

What efficiency did that recipe assume?

It didn't say.

What is the recipe and where did you find it?

When I see someone say they hit 75% efficiency I think, well, 75% of what?

https://www.brewersfriend.com/brewhouse-efficiency/

 

[kohalajohn]

What is the recipe and where did you find it?

https://www.brewersfriend.com/brewhouse-efficiency/

Thx

 

[VTMongoose]

Like @Bobby_M said this is definitely an issue with grains simply not being mashed but my tendency is to firstly suspect an issue with dough balls or a stuck mash first. Even when I perform a single infusion on my own AIO system, unless the grain bill is extremely small (<=60% of my total capacity), I almost always have to stir the mash multiple times. For example, I will usually stir the mash at dough-in with a large whisk/whip to break up dough balls, and then I will additionally stir again with my paddle after 10-15 minutes and again after around 30-45 minutes. I have consistently found that when I do this, I will see air bubbles rise to the surface indicating that the grains are now being fully wetted. This happens no matter how carefully I mash in.

The most important thing you can do is get yourself one of these refractometers and check your specific gravity BEFORE you mash out. You can ALWAYS mash longer, but you cannot "fix" missing your OG by a gazillion points by boiling longer.

I always check my SG at around 40 minutes because if I'm not "nearish" my target pre-boil at that point, it's always one of three major problems:

1) Dough balls (stir the mash)
2) Stuck mash/channeling (stir the mash and reduce recirc speed)
3) Wrong mash temperature (mash was stuck during temperature step - stir the mash and wait for it to come to temp)

 

[Bobby_M]

Any "recipe" that just gives you grain amounts isn't really doing you any favors. It's more a record of what one brewer did once.

I normally would go on and on about how you are supposed to adjust recipes to your own process without worrying too much about your efficiency numbers but yours were under 30% which is objectively problematic. The grain you got might not have been actual malt. Maybe it was uncrushed. If you were measuring gravity occasionally during the mash you would have discovered the problem on the spot.

 

[MaxStout]

Seconded on the refractometer. Best $20 you can spend for testing your mash.

Do an iodine test to see if conversion is complete. You can get little bottles of tincture of iodine from the drugstore.

 

[kohalajohn]

Agreed. I’m not saying it’s inherently better and I probably wasn’t particularly clear in my last post. I was just trying to point out where OP was departing from how his system was designed or traditionally used.

I’m wondering if what is happening to the OP is that the recirculating wort is blasting right through the grain and out the center drain. If he’s not using the top diffuser plate, has the recirculation hose pointed straight down into the grain, doesn’t have the HED plate, and is running his pump at full speed, it seems possible that he’s running a jet of wort right through the grain. Idk if a thick or thin mash would affect that at all, I just thought it might be one possibility.

I think you're largely right Whisky. I did not use the top plate, I did not use a heat diffuser plate and I had the pump on full. My next mash will be very different.

 

[kohalajohn]

Ok. Have been reading and learning a ton. Will see how next mash goes

Am ordering a heat exchange plate.

I have been getting mash temperature swings, so will be setting up the PID per kegland recommendations.

Finally, I will probably buy the Bluetooth mash thermometer.

Question. Does the rapt PILL also work in the mash as a mash temp controller? Seems it would not be as good as the kegland mash thermometer, as the PILL would only give you temp at the surface of the mash. And you could not use the mash top plate.

 

[Yooper]

By "full volume mash", do you mean you didn't do any sparge? No sparge would reduce efficiency.

I get good efficiency in my BZ g4, using strike water = batch volume (usually 23L) Then sparge with 9L or so.

I do a full volume mash, and my efficiency is about 1% lower than when I sparge, so not at all a big deal. I've read journals over the years that will often say that a no-sparge 'results in a higher quality wort', for what that's worth.

I would not recommend sparging to try to fix this problem just because it's absolutely not why the efficiency is some 40% lower than it should be. A sparge on an AIO is maybe worth an extra 5% like the difference between 70 and 75%.

If I'm doing the math right, OP got about 28% brewhouse efficiency which means almost everything went wrong.

Here's the priority of troubleshooting in my opinion:
1. What does the crush look like? With those numbers, I'd wager most of the grain wasn't even cracked open.
2. With a visual inspection that the grain is all adequately cracked, move on to monitoring the mash wort's gravity as it rises and plateaus during the mash.

6.5kg is 14.3 LBs (sorry I'm still trying to think metric but can't). At a reasonable 70% mash efficiency, the preboil/mash liquor gravity should reach 1.070. That's even before boil concentration and the 500g of sugar added.
Even a dismal mash efficiency of 50% would get your mash liquor gravity to 1.050 at the end of the mash.

In other words, you were barely mashing.

The recirculation rate, diffusion method and all that can't have a 40% degradation of efficiency.

I agree, and think @Bobby_M said it way better than I could.

Ok. Have been reading and learning a ton. Will see how next mash goes

Am ordering a heat exchange plate.

I have been getting mash temperature swings, so will be setting up the PID per kegland recommendations.

Finally, I will probably buy the Bluetooth mash thermometer.

Question. Does the rapt PILL also work in the mash as a mash temp controller? Seems it would not be as good as the kegland mash thermometer, as the PILL would only give you temp at the surface of the mash. And you could not use the mash top plate.

Even with the HED, I had some clogging issues. I crush pretty fine, though. It definitely will help with temperature control (hot spots vs cold spots).

I bought the bluetooth thermometer, and it does work pretty well. The thing I've had with mine is that the element heating temperature is much warmer, and so I had some unexpected lower attenuation due to the likelihood of that higher temperature. The last brew day a few days ago, I didn't use the bluetooth thermometer at all, just used my old thermapen to check temperature, and the wort temperature was about 5 degrees cooler than the heating element temperature, even with recirculation.

I'm not a Rapt pill owner, but my understanding that it (like Tilt, which I do have) isn't to be used at mash temperatures, but double check that!

 

[doug293cz]

Seconded on the refractometer. Best $20 you can spend for testing your mash.

Do an iodine test to see if conversion is complete. You can get little bottles of tincture of iodine from the drugstore.

No need for an iodine test if you mash until SG plateaus.

Brew on

 

[Bobby_M]

I bought the bluetooth thermometer, and it does work pretty well. The thing I've had with mine is that the element heating temperature is much warmer, and so I had some unexpected lower attenuation due to the likelihood of that higher temperature. The last brew day a few days ago, I didn't use the bluetooth thermometer at all, just used my old thermapen to check temperature, and the wort temperature was about 5 degrees cooler than the heating element temperature, even with recirculation.

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.