New equipment and horrible efficiency

[DHOMD]

Last year, I "upgraded" my mash tun from a basic cooler to a Chapman 10 Gallon mash tun and since then I get less than 50% efficiency.
I have been all-grain brewing since the 1990s, but I cannot figure out why the efficiency frankly sucks.

I have done about 10 brews with stirring more/less stirring, different saccharification temps, different recipes and improvement in final gravity.
No off tastes and good clean beer.

On BeerSmith I have lowered my efficiency to 65% and I'm getting 65% of that.

Set up:
Ferroday Malt Crusher
Chapman 10 Gallon Mash tun with false bottom
RIMs Rocket
Digital temperature controller for RIMs
Cheap hot water pump
20+ year old 10 gallon kettle
Copper coil heat exchange
Various 5-8 gallon carboys and fermentation buckets.

Today, I mashed in a high gravity Hefeweizen with Starfruit added in the primary.
To help eliminate grain milling as a variable, today I used pre-crushed grains directly from Marris Otter I obatined from a professional brewery. (Minimal difference in gravity from milling at home)

Mash tun with RIMs heating. Pump moves ~3 gallons a minute.
The mash after 30 minutes at 148 had a pH of mid 5s and SG of 1.085
The first wash 15 minutes at 152 had a pH of mid 5s and SG of 1.038
The sparge final temp 160 and a pH of mid 6s and SG of 1.033

Post boil gravity is 1.066.
Target SG: 1.0.98 @ 65% efficiency.

When I add water, I always let the grains settle to avoid dough balls.
I keep the thermometer near the top of the grains, near the hot water RIMs to avoid scotching.
There is good steady slow through the RIMs. The canister is clean at the end, so not sucking up grains.
During the entire process, I stir 2-3 times, let it settle, then resume the RIMs.

Same well water I have used for a decade.
Same volumes, same pot, same fermentors,....
Only difference is re-circulation vs stagnant cooler.

My best guess is perhaps since I tend to brew imperials, barley wines, and other gravity beer. The mash tun simply does not have the capacity, but I do not see why 2-3 washes with better temperature control and re-circulation should not achieve the same goal as dumping hot water in a cooler and letting it sit stagnant.

At this point,... I cannot figure it out. So any ideas?

 

[Birrofilo]

Recirculation can be bad if preferential paths are formed in the mash.

The problem might lie in the way the recirculated wort is reinserted in the mash.

I use a much smaller AIO system and I recirculate slowly and through an upper screen so that the wort coming from below is spread evenly on the mash mass and hopefully also to avoid temperature inequalities. 3 gallons a minute seem to me an unnecessarily fast recirculation in any case.

Also, dough balls can be formed and I think you should act mechanically on the mash to liquefy them, rather than relying on the grain to "settle".

I am totally inexperienced so don't trust my advice too much. I hope somebody else will give you a better advice.

 

[DHOMD]

Thanks

I can try slowing it down on next run. Definitely worth a try

 

[jrgtr42]

Do you still have the old cooler? Might be worth throwing a batch through there just to make sure there not something else going on.

 

[Birrofilo]

I can try slowing it down on next run. Definitely worth a try

Do you use some kind of a "shower" system, or do you reinsert the wort flow directly in the kettle? A "shower" system might create an oxygenation of the wort, which is supposedly sub-optimal.

A direct insertion of the flow in the grain might easily create some path especially if the flow is fast.

As I said, I use a screen which is like a "false bottom" but on the top of the mash. The wort falls over the "false bottom" but below the level of the wort, to avoid splashing and oxygenation. This creates a "whirlpool" above the screen, which should hopefully guarantee a uniform fall of the liquid over the surface of the mash.

 

[Gnomebrewer]

The mash after 30 minutes at 148 had a pH of mid 5s and SG of 1.085
The first wash 15 minutes at 152 had a pH of mid 5s and SG of 1.038
The sparge final temp 160 and a pH of mid 6s and SG of 1.033

At normal mash thickness, 100% mash efficiency is about 1.095, so you're probably losing about 10% efficiency in the mash (which is probably somewhere around normal; you can do better though - I aim for 95%). Use this spreadsheet http://braukaiser.com/documents/efficiency_calculator.xls to calculate your mash efficiency. So, it looks like your sparge is the issue.

I don't know what you mean by 'first wash 15 minutes'. Is that the runoff after 15 minutes of fly sparging? 'Wash' is a term normally used in distilling, not beer brewing.

Post boil gravity is 1.066.
Target SG: 1.0.98 @ 65% efficiency.

That's poor efficiency, even for such a big beer. 65% efficiency is about right for a beer of that size.

My best guess is perhaps since I tend to brew imperials, barley wines, and other gravity beer.

Yep, they're definitely more of a challenge. Consider adding some sugar/DME/LME to make up some of the gravity points. Without a super-long boil you're not collecting much more than first runnings for a beer of that size made entirely from grains.

I do not see why 2-3 washes with better temperature control and re-circulation should not achieve the same goal as dumping hot water in a cooler and letting it sit stagnant.

Surprising as it may be, a simple cooler mash tun with batch sparge (or BIAB) is normally just as good as a fancy RIMS with fly sparge.

 

[Gnomebrewer]

Are you batch sparging, or fly sparging?

 

[Gnomebrewer]

Hmmm, looking at your brew log, it seems you're only boiling off half a gallon. Your efficiency on a beer this size is always going to suck if that's all you boil off. It's limiting you to a 2 gallon sparge. If you boil more aggressively and for longer, you could double that sparge which will give a big jump in efficiency. Also, 3 gallons per minute is too fast to run a pump for RIMS on a 5 to 6 gal system. Try running at about 1 gallon per minute.

 

[couchsending]

Guarantee you it’s your sparging regimen that’s hurting you... do you let the grain bed compact at all be fore you start your sparge? How quick is your sparge? Longer and slower you can make it the better your efficiency will be.

 

[DHOMD]

Do you still have the old cooler? Might be worth throwing a batch through there just to make sure there not something else going on.

Nope, wish I did

 

[DHOMD]

Do you use some kind of a "shower" system, or do you reinsert the wort flow directly in the kettle? A "shower" system might create an oxygenation of the wort, which is supposedly sub-optimal.

A direct insertion of the flow in the grain might easily create some path especially if the flow is fast.

As I said, I use a screen which is like a "false bottom" but on the top of the mash. The wort falls over the "false bottom" but below the level of the wort, to avoid splashing and oxygenation. This creates a "whirlpool" above the screen, which should hopefully guarantee a uniform fall of the liquid over the surface of the mash.

I was considering a chandelier of some sort. I think it is a good idea

 

[DHOMD]

Are you batch sparging, or fly sparging?

Have tried both
Batch seems to give better results

 

[DHOMD]

Guarantee you it’s your sparging regimen that’s hurting you... do you let the grain bed compact at all be fore you start your sparge? How quick is your sparge? Longer and slower you can make it the better your efficiency will be.

I add water
Wait about 5 minutes then restart the RIMs and re-circulation.
It typically takes about 10 minutes to get back to temp and I leave it there 10-15 minutes. So 20-30 minutes from water addition to drain

 

[DHOMD]

At normal mash thickness, 100% mash efficiency is about 1.095, so you're probably losing about 10% efficiency in the mash (which is probably somewhere around normal; you can do better though - I aim for 95%). Use this spreadsheet http://braukaiser.com/documents/efficiency_calculator.xls to calculate your mash efficiency. So, it looks like your sparge is the issue.

I don't know what you mean by 'first wash 15 minutes'. Is that the runoff after 15 minutes of fly sparging? 'Wash' is a term normally used in distilling, not beer brewing.



That's poor efficiency, even for such a big beer. 65% efficiency is about right for a beer of that size.



Yep, they're definitely more of a challenge. Consider adding some sugar/DME/LME to make up some of the gravity points. Without a super-long boil you're not collecting much more than first runnings for a beer of that size made entirely from grains.



Surprising as it may be, a simple cooler mash tun with batch sparge (or BIAB) is normally just as good as a fancy RIMS with fly sparge.

I think I agree with you that BIAB might be 'just as good' if not better

By 'wash,' I believe runoff would be the proper terminology. I have brewed in both worlds, so forgive me if I mix and match terminology.
With 20+ lbs of grains, a 10 gal mash tun typically requires a mash, run off, then a sparge to get my volume.
I cannot get the required volume for boil in just a mash immediately followed by a sparge, so a middle wash/ runoff is required.
With smaller grain bills, a traditional mash and sparge is fine for volume. But efficiency is still down.

I will play around with the calculator. I have not seen that site before. Thanks!

 

[doug293cz]

...

Mash tun with RIMs heating. Pump moves ~3 gallons a minute.
The mash after 30 minutes at 148 had a pH of mid 5s and SG of 1.085
The first wash 15 minutes at 152 had a pH of mid 5s and SG of 1.038
The sparge final temp 160 and a pH of mid 6s and SG of 1.033

Post boil gravity is 1.066.
Target SG: 1.0.98 @ 65% efficiency.

...

For 21.6 lb of grain (assuming a weighted potential of 37ppg) and 7.5 gal (30 qt) of strike water, I get a max mash SG of 1.087. Your value of 1.085 after the first sac rest works out to 97% conversion efficiency, which is pretty good.

But then, the second red line you show an SG of 1.038 after the second sac rest. It doesn't make sense for the SG of the mash to go down with time, so not sure what's going on here. Am I misinterpreting what you mean by "first wash"? What exactly is your run-off and sparge water addition process?

Brew on

 

[madscientist451]

Mash tun with RIMs heating. Pump moves ~3 gallons a minute.

At this point,... I cannot figure it out. So any ideas?

MY ideas are based on my personal experience, so they may or may not work for you. I started out BIAB, went to cooler mash tun and fly and then batch sparging and now I'm back to BIAB and get high efficiency.

So my idea is to quit using the RIM's heating and pump. Pre heat the mash tun with hot water, heat your strike water to the proper temperature, add the grain, stir it, put the lid on and forget about it for 2 hours or more, go do something else. If the Chapman (insulated) mash tun is losing too much heat, wrap it up in some insulation or a blanket or old coat.
Run off your first runnings and do a batch sparge and see how that works for you.

 

[DHOMD]

For 21.6 lb of grain (assuming a weighted potential of 37ppg) and 7.5 gal (30 qt) of strike water, I get a max mash SG of 1.087. Your value of 1.085 after the first sac rest works out to 97% conversion efficiency, which is pretty good.

But then, the second red line you show an SG of 1.038 after the second sac rest. It doesn't make sense for the SG of the mash to go down with time, so not sure what's going on here. Am I misinterpreting what you mean by "first wash"? What exactly is your run-off and sparge water addition process?

Brew on

To get the required volume in the boil, for anything over ~16 lbs grain I need todo a mash, run off / wash, then a final sparge.
So after the primary mash, I drain everything out, fill up and get the temperature back up for a another sac rest. Then the final sparge

For < 15 lbs, I do the traditional mash followed by sparge. Efficiency is still awful.

So based on the math, sounds like off a good start... maybe washing out the enzymes so not getting enough sugar/volume on subsequent run off.

 

[DHOMD]

MY ideas are based on my personal experience, so they may or may not work for you. I started out BIAB, went to cooler mash tun and fly and then batch sparging and now I'm back to BIAB and get high efficiency.

So my idea is to quit using the RIM's heating and pump. Pre heat the mash tun with hot water, heat your strike water to the proper temperature, add the grain, stir it, put the lid on and forget about it for 2 hours or more, go do something else. If the Chapman (insulated) mash tun is losing too much heat, wrap it up in some insulation or a blanket or old coat.
Run off your first runnings and do a batch sparge and see how that works for you.

The chapman tun is amazing at holding on to heat.

I usually put grains in 1st. Usually do a 10 min acid rest. The heat until the sac rest.

But would be happy to try pre-heating first

 

[doug293cz]

To get the required volume in the boil, for anything over ~16 lbs grain I need todo a mash, run off / wash, then a final sparge.
So after the primary mash, I drain everything out, fill up and get the temperature back up for a another sac rest. Then the final sparge

For < 15 lbs, I do the traditional mash followed by sparge. Efficiency is still awful.

So based on the math, sounds like off a good start... maybe washing out the enzymes so not getting enough sugar/volume on subsequent run off.

You should be trying to get complete conversion (saccharification) prior to the initial run-off, so that no additional conversion needs to take place during the sparge(s). The sparge then just becomes a rinsing operation to get more of the residual sugar out of the grain mass.

Given that you were at ~97% conversion efficiency after the first sac rest (assuming your SG measurement is accurate), then you couldn't have had significant conversion during your first batch sparge (which you refer to as "wash".) What is inconsistent is that a simulation of your process shows that the runnings from your first batch sparge should have had an SG of about 1.065, and from your second batch sparge of about 1.050. Your pre-boil SG (combination of all three runnings) should have been somewhere around 1.076. The fact that your readings for sparge runnings are much lower than this leads me to believe that your first mash SG reading of 1.085 is seriously in error. Can you describe how you take your SG samples?

Brew on

 

[cire]

To get the required volume in the boil, for anything over ~16 lbs grain I need todo a mash, run off / wash, then a final sparge.
So after the primary mash, I drain everything out, fill up and get the temperature back up for a another sac rest. Then the final sparge

For < 15 lbs, I do the traditional mash followed by sparge. Efficiency is still awful.

So based on the math, sounds like off a good start... maybe washing out the enzymes so not getting enough sugar/volume on subsequent run off.

This could be your problem. Run-off and sparging should not begin until starches are converted to sugar else you risk removing unconverted starch from the mash. An iodine test will confirm if starch is still present.

RIMS has a potential of overheating recycled wort to quickly denaturing enzymes that convert starch to sugars.

 

[Brewbuzzard]

This could be your problem. Run-off and sparging should not begin until starches are converted to sugar else you risk removing unconverted starch from the mash. An iodine test will confirm if starch is still present.

RIMS has a potential of overheating recycled wort to quickly denaturing enzymes that convert starch to sugars.

I agree with this completely plus the recirculation of 3 gal per minute is way too fast. Also stir and check closely for starch balls.

 

[DHOMD]

You should be trying to get complete conversion (saccharification) prior to the initial run-off, so that no additional conversion needs to take place during the sparge(s). The sparge then just becomes a rinsing operation to get more of the residual sugar out of the grain mass.

Given that you were at ~97% conversion efficiency after the first sac rest (assuming your SG measurement is accurate), then you couldn't have had significant conversion during your first batch sparge (which you refer to as "wash".) What is inconsistent is that a simulation of your process shows that the runnings from your first batch sparge should have had an SG of about 1.065, and from your second batch sparge of about 1.050. Your pre-boil SG (combination of all three runnings) should have been somewhere around 1.076. The fact that your readings for sparge runnings are much lower than this leads me to believe that your first mash SG reading of 1.085 is seriously in error. Can you describe how you take your SG samples?

Brew on

I have become a bit obsessive with gravity. So at the end of each step I use a hydrometer in a 250 ML cylinder.
I spot check occasionally with a refractometer

And I have a Tilt 2 in the fermemter

All of the measurements are typically +/0 0.003

 

[DHOMD]

This could be your problem. Run-off and sparging should not begin until starches are converted to sugar else you risk removing unconverted starch from the mash. An iodine test will confirm if starch is still present.

RIMS has a potential of overheating recycled wort to quickly denaturing enzymes that convert starch to sugars.

I have have not tried iodine, but it's cheap and worth a try

I keep the thermometer controller near the hot mash in... to prevent over heating, but enzyme inactivation is a concern of mine

 

[DHOMD]

I agree with this completely plus the recirculation of 3 gal per minute is way too fast. Also stir and check closely for starch balls.

I am going to build a sprinkler system for more even flow and should decrease flow a bit. If it works I'll post a few photos.

 

[DHOMD]

It will probably be 2 weeks before my next run, but I made a diffuser for the hot wort returning to the mash tun.
In theory, will give more even flow across the surface and some back pressure to slow the system down.

$4 copper water hammer pipe
$2 1/2 inch NPT fitting
Welded
Screwed into the mash tun, to mark the top
Then marked the bottom
Drilled it out with 5/32nd bit, left more room at end in case I need bigger holes (dont want water jets)

Will be a few weeks before I use it, but will report back.

 

[Brewbuzzard]

It will probably be 2 weeks before my next run, but I made a diffuser for the hot wort returning to the mash tun.
In theory, will give more even flow across the surface and some back pressure to slow the system down.

$4 copper water hammer pipe
$2 1/2 inch NPT fitting
Welded
Screwed into the mash tun, to mark the top
Then marked the bottom
Drilled it out with 5/32nd bit, left more room at end in case I need bigger holes (dont want water jets)

Will be a few weeks before I use it, but will report back.



View attachment 719959View attachment 719961

When you say back pressure to slow the flow don't you have a ball valve at the pump?

 

[DHOMD]

When you say back pressure to slow the flow don't you have a ball valve at the pump?

I have a ball valve before the pump. Not after the pump.
I dont like limiting flow before the pump, so I haven't used it much

Perhaps another to add to the rig. That would assist in keeping the prime

 

[ajm163]

my guess (as others have stated) is you are recirculating too fast and creating channels through the grain bed. one easy test is don't recirculate on your next batch and see what your efficiency is. if its way up you have found the problem. i would put a valve on the pump outlet so you can dial the flow back and are able to easily control the rate

 

[Brewbuzzard]

This is the setup I have.

 

[DHOMD]

This is the setup I have.

Amazingly clean rig, I love it.

I have to store mine between brews, so no where near as nice.
Embarrassingly, this is the best photo I have on the phone.

 

[Brewbuzzard]

Amazingly clean rig, I love it.

I have to store mine between brews, so no where near as nice.
Embarrassingly, this is the best photo I have on the phone.

View attachment 719978

I would have killed for your setup when I first started. I brewed in the kitchen with a large soup pot and then diluted to five gal in the carboy. What I have now is a 22 year old dream come true. I am a gadget head but brewing great beer is mainly due to the brewer not the equipment. Fancy equipment just makes it easier not better.
Prost

 

[DHOMD]

Update in case anyone else reads this thread in the future


I have suspicion that it was hydrodynamics of the re-circulation as suggested.

Last few brews have done much better.
I have done a 12% barley wine
10% imperial coffee chocolate oatmeal stout
and an 8% 'imperial' loquat wheat

All of them have gotten to about 90% expected efficiency (of 60%) with just adding in that diffuser that I made on the return to the mash tun.
That diffuser has been extremely effective at gently distributing the mash over the surface rather than just splashing in and stirring things up.
I have been fanatical at checking pHs and consistantly get 5.1-5.4.

I plan on making a 'normal' wheat beer this weekend and since it will only have a ~1.06 gravity, so I'm hoping as as expected efficiency.

I know there is room for more improvement,... hopefully each batch gets better.