Double Crush for better efficiency?

[rtstrider]

I'm currently working to diagnose efficiency issues on a new to me setup. I moved from BIAB to a 3 tier setup and have had horrible efficiency. BIAB I was getting 70% and up. On the 3 tier I've only hit that once and that was with an all Avangard pilsner malt 90 minute mash. I do fly sparge and at the end of brewday I'm hitting around 58% efficiency. I have a theory the shop I've been getting the grains from (new shop) may not be crushing them as tight as the old shop. On my old BIAB setup I would have the shop double crush the grains and never had issues. So my question is would there be any potential issues, stuck sparge, etc if I asked the previous shop to double crush the grains in the new mash tun setup? The setup is large cylinder coolers. I would not be opposed to throwing in rice hulls if that might be needed with the double crush.

Now with that said here's my current process

Use the following Mash/Sparge water calculator for volumes https://www.mibrewsupply.com/recipe/mash

Heat mash water (add brewing salts) to temp specified by brewers friend.
Let the mash water sit in the mash tun for 10 minutes or so to preheat.
Add grains, stir, close the lid, check in 10-15 minutes for temperature and adjust as needed
Heat fly sparge water to 168F-170F
After 60 minutes (if the mash is 150F or higher) vorlauf until the crud is longer showing in pitchers (crud being loose grain and such) to set the bed
Drain/Fly sparge for 45-60 minutes
Boil, add hops, cool, transfer to glass carboy, take hydro sample

I use RO water only but have thought about investing in Campden tablets. I have a charcoal refridgerator water filter and figured I could use that plus Campden to clear out any chlorine. I reached out to the local water company and they said they do use low amounts of chlorine.

Now one other thing that caught my eye is my boil amounts are a tad higher than what the recipe calls for. Meaning I'm boiling roughly 6.75 gallons instead of 6.5 gallons. However the efficiency shouldn't be 15 points off or so because of a quarter gallon difference I wouldn't think. Apologies for the long winded post but I'm at wits end lol Have seriously considered going back to BIAB and giving up no the 3 tier.

 

[brownni5]

A finer crush will usually lead to better extraction (i.e. efficiency), but some say that it also leads to undesirable tannin extraction. I haven't experienced that to date, at least not that I can notice.

One reason BIAB is so popular is that the mesh bag provides the filter for the grain bed, allowing for a finer crush with fewer downsides. A fine crush on a more traditional setup may lead to slow runoff - rice hulls could solve this problem. You'll likely have to experiment with the new system to get your best and most consistent results.

 

[kh54s10]

It is really odd that you get lower efficiency with a 3 tier than BIAB. You should be getting better efficiency. Are you getting the proper volumes? Thermometer is accurate.

Crush is important. Can you see a difference between the two LHBSs? If the new one is crushing much more coarse than the previous, that could be the issue. Double crushing may help. I don't believe in the tannin extraction. BIAB crushed to powder does not suffer.

Good time to look into getting your own mill. That way you can tighten until you get a slow draining, then back off slightly.

 

[IslandLizard]

Drain/Fly sparge for 45-60 minutes

Are you draining first, then start the fly sparge?

Are you using a single braid in your mash tun? That would explain a lot.

Can you try batch sparging to see if your efficiency improves? May also save you 1/2 hour, as it is much quicker.

 

[kh54s10]

Are you draining first, then start the fly sparge?

Are you using a single braid in your mash tun? That would explain a lot.

Can you try batch sparging to see if your efficiency improves? May also save you 1/2 hour, as it is much quicker.

To expand on this, if you are using a braid you may be experiencing channeling. That is the sparge is taking a straight line to the outlet end of the braid and most of the grain bed does not get sparged. You need a false bottom where the draining at the bottom is consistent all the way across.

 

[rtstrider]

Are you draining first, then start the fly sparge?

Are you using a single braid in your mash tun? That would explain a lot.

Can you try batch sparging to see if your efficiency improves? May also save you 1/2 hour, as it is much quicker.

As soon as I open the valve on the mash tun I match the flow with the hot liquor tank so the grain bed does not run dry initially. I try to keep an inch or two (two inches tops) of water above the grains until the hlt runs dry. Once the hot liquor tank is empty I let the grains in the mash tun run dry until I hit my pre-boil volume. I don't have any braid in the mash tun. It's a false bottom. It's one of the OLD Northern Brewer all grain setups. It's essentially this without the sparge arm

https://www.northernbrewer.com/coll...its/products/northern-brewer-all-grain-system

I have one of those el cheapo plastic diverters and silicone hose hooked up.

This is the fly sparge fitting I have

https://www.northernbrewer.com/products/fermenters-favorites-fighter-jet-sparge


kh54s10 I have the Northern Brewer 3 tier setup. It is the round coolers with the false bottom in the mash tun. In regards to the crush the newer lhbs has a coarser crush. The old lhbs I was going to had a finer crush. I always asked them to double crush due to biab.

 

[IslandLizard]

I'd say look into the crush first. Brew stores typically mill too coarsely. Many a lot coarser.
Do you know a home brewer (e.g., a club member) who can mill for you?

IMO, there should be no grain bit larger than 3/32" diameter, and hulls should remain fairly whole, very little shredding or flaking. There should also be very little powder, as that may plug up your sparge.

There's a limit to how fine you can crush when fly sparging, as the wort needs to be able to move downward, at a decent rate, rinsing the sugars off the grist particles on her way down.

With BIAB you can crush down to a coarse cornmeal consistency (as small as the "ball bearings" under a pizza), due to using the mesh filter. With a fine BIAB-type crush, 70% mash efficiency is pretty poor, mid to upper 80's is not uncommon.

If you have any wheat, rye, oats, or other small kernel grain in your grist, a gap that's too wide won't crush those, even if you run it through 5x. Keep that in mind. Use narrower gaps for smaller grain. Proper crushing once through is better than double crushing, although doing the latter may help somewhat.

You could still have channeling. You can test for sugar content left behind.

Do you stir that mash well enough? What's your water to grain ratio?

To keep the amount of variables manageable to find the problem, why not do a double batch sparge (using equal volumes) and keep a record of the 3 lautered volumes and their respective gravities? Volume x points should give you the total extraction points for each lauter fraction. Add all together and compare to your recipe's pre-boil target gravity.
Make sure your mash tun's deadspace volume, and thus wort left behind after each lautering, is minimal.

 

[rtstrider]

I'd say look into the crush first. Brew stores typically mill too coarsely. Many a lot coarser.
Do you know a home brewer (e.g., a club member) who can mill for you?

IMO, there should be no grain bit larger than 3/32" diameter, and hulls should remain fairly whole, very little shredding or flaking. There should also be very little powder, as that may plug up your sparge.

There's a limit to how fine you can crush when fly sparging, as the wort needs to be able to move downward, at a decent rate, rinsing the sugars off the grist particles on her way down.

With BIAB you can crush down to a coarse cornmeal consistency (as small as the "ball bearings" under a pizza), due to using the mesh filter. With a fine BIAB-type crush, 70% mash efficiency is pretty poor, mid to upper 80's is not uncommon.

If you have any wheat, rye, oats, or other small kernel grain in your grist, a gap that's too wide won't crush those, even if you run it through 5x. Keep that in mind. Use narrower gaps for smaller grain. Proper crushing once through is better than double crushing, although doing the latter may help somewhat.

You could still have channeling. You can test for sugar content left behind.

Do you stir that mash well enough? What's your water to grain ratio?

To keep the amount of variables manageable to find the problem, why not do a double batch sparge (using equal volumes) and keep a record of the 3 lautered volumes and their respective gravities? Volume x points should give you the total extraction points for each lauter fraction. Add all together and compare to your recipe's pre-boil target gravity.
Make sure your mash tun's dead space volume, and thus wort left behind after each lautering, is minimal.

I stir every 15 minutes and originally started with a 1.25 ratio. I have since moved to 1.8 to see if that may be the issue. I hit my numbers for 70% efficiency the first time the 1.8 ratio was in place. That was for 70% efficiency. I'd be willing to try the batch sparge for giggles. My next batch is Friday and it's 90% two row 10% c40. Wanted to keep it very simple while I work out the kinks. It's an 11 lb grain bill. For the double batch sparge would I dough in at 1.25, vorlauf, drain, then split what I would normally fly sparge with in half vorlaufing at each batch sparge?

 

[IslandLizard]

I stir every 15 minutes and originally started with a 1.25 ratio. I have since moved to 1.8 to see if that may be the issue. I hit my numbers for 70% efficiency the first time the 1.8 ratio was in place. That was for 70% efficiency. I'd be willing to try the batch sparge for giggles. My next batch is Friday and it's 90% two row 10% c40. Wanted to keep it very simple while I work out the kinks. It's an 11 lb grain bill. For the double batch sparge would I dough in at 1.25, vorlauf, drain, then split what I would normally fly sparge with in half vorlaufing at each batch sparge?

I mostly use a 1.50 qt/lb water/grain ratio, 1.25 is quite a bit too thick, IMO.

Yes, split the sparge water in 2 equal amounts. For each sparge, add the sparge water, stir very well (as if it owes you money), vorlauf and drain each completely (or close enough). I get 80-85% mash efficiency that way. But I mill fairly fine, 0.034" for barley and 0.025" gap for small kernel grain such as wheat and rye. Oat malt even a tad narrower.

Maybe look into buying a mill. Proper milling makes all the difference.

 

[rtstrider]

I mostly use a 1.50 qt/lb water/grain ratio, 1.25 is quite a bit too thick, IMO.

Yes, split the sparge water in 2 equal amounts. For each sparge, add the sparge water, stir very well (as if it owes you money), vorlauf and drain each completely (or close enough). I get 80-85% mash efficiency that way. But I mill fairly fine, 0.034" for barley and 0.025" gap for small kernel grain such as wheat and rye. Oat malt even a tad narrower.

Maybe look into buying a mill. Proper milling makes all the difference.

I'll make sure to notate on the grain order that I have been having low efficiency issues. Crush as fine as they think they can to help bump up the efficiency and that I am using a fly sparge setup. This is run by a BJCP judge so I'd hope they'd be able to point me in the right direction there. Right now I'm still doing split batch boils so that may cause issues as well

 

[doug293cz]

To better diagnose efficiency issues, you need to measure conversion efficiency and lauter efficiency separately. Crush pretty much affects only conversion efficiency, and sparge process affects lauter efficiency. Finer crush promotes faster and more complete conversion. Longer mashes can (at least partially) mitigate the effects of slower conversion when you have a coarser crush.

Use the method here to measure your conversion efficiency. If it's not 95% or better, you should address with crush and mash time. Mash efficiency equals conversion efficiency times lauter efficiency. Use your brewing software to calculate your mash efficiency, and then calculate your lauter efficiency as:

Lauter Efficiency = Mash Efficiency / Conversion Efficiency​

The chart below shows what can be achieved with various numbers of batch sparges for two different grain absorption rates. 0.12 gal/lb is typical for an MLT without any squeezing. If you cannot beat the solid orange line with your fly-sparge efficiency, you are wasting your time, and should just batch sparge. A well conducted fly-sparge can beat the solid green line by a few percentage points. Poor fly-sparge lauter efficiency is almost always due to channeling.

Brew on

 

[rtstrider]

The more I'm researching it's looking like I need to fine tune my technique and numbers. I've got the boil off rate and such but I did not account for the mash tun loss. So I'm going to measure that when I get home and fine tune a few other mathy things. I'm taking notes and seeing where I get this brew. If even just a tad over 58% I'll chalk it up a a win

 

[doug293cz]

The more I'm researching it's looking like I need to fine tune my technique and numbers. I've got the boil off rate and such but I did not account for the mash tun loss. So I'm going to measure that when I get home and fine tune a few other mathy things. I'm taking notes and seeing where I get this brew. If even just a tad over 58% I'll chalk it up a a win

MLT losses (undrainable MLT volume) will decrease your lauter efficiency, which also decreases your mash efficiency (has no effect on conversion efficiency.) It has the same effect as grain absorption, but is a constant loss, rather than being proportional to grain bill weight. However, MLT losses should have less effect when fly-sparging vs. batch sparging. Boil off rate does not affect efficiency directly.

Brew on

 

[rtstrider]

MLT losses (undrainable MLT volume) will decrease your lauter efficiency, which also decreases your mash efficiency (has no effect on conversion efficiency.) It has the same effect as grain absorption, but is a constant loss, rather than being proportional to grain bill weight. However, MLT losses should have less effect when fly-sparging vs. batch sparging. Boil off rate does not affect efficiency directly.

Brew on

Well I dialed in my boil off rate, mash tun loss, and see exactly where I may have screwed up. This may be a screw up on the brewer and not the lhbs. I’ve taken notes and feel the numbers are dialed in My screw up is I’m using brewers friend and had the fermenter volume set to 5 gallons. I set the batch size to 5 gallons using the MIBREW mash and sparge volume calculator. This gives me around 5.5 gallons in the fermenter. Anywho I’ve plugged the numbers in for the next batch and will keep everyone posted! On a side note what mash/grist ratio do you try and get? I see 1.5 mentioned above

 

[JohnMc]

If you still have the BIAB stuff, it might be worth it to test the new shop's crush with that method, I would bet your efficiency there would suffer as well.
Also, make sure you have enough calcium in the mash, efficiency suffers without it.
As many have said, the crush is critical. Having your own mill is pretty darned cool.

 

[doug293cz]

There is nothing magic about any particular mash/grist ratio. For batch sparging, you get optimal lauter efficiency if you adjust strike and sparge volumes to get equal run-off volumes. The only limitation is that you may need to adjust the strike volume upwards in order to get a mash that can be stirred. For fly sparging, you get maximum lauter efficiency with minimum strike water, with the balance of the required water used for sparging. Water to grist ratio should be as low as you are comfortable w.r.t. mash stirring. But, thicker grists can slow down conversion rate in the mash.

Personally, I do full volume, no-sparge mashing, so my water to grist ratios are very high, and also variable depending on grain bill size.

Brew on

 

[hottpeper13]

Why not get the grains double crushed and put your bag from the old set up in your new mash tun and do a MIAB. I had a rectangular bag made and leave the braid in and crush my grains to .028 with 80% efficiency.

 

[rtstrider]

Why not get the grains double crushed and put your bag from the old set up in your new mash tun and do a MIAB. I had a rectangular bag made and leave the braid in and crush my grains to .028 with 80% efficiency.

I was doing split batch setups. This is a 10 gallon mash tun and I only have 5 gallon paint strainer bags. That is definitely a thought IF the number changes and such help. I still may invest in a brew bag though for the higher gravity brews just for the finer crush alone (aka potential efficiency boost)

 

[kh54s10]

I'm a little lost on this. 58% efficiency is so low it would be hard to achieve if you tried. You would need to collect almost twice as much wort as the recipe calls for or have almost no crush on the grains.

I think this is a calculation error. Something is not right in the inputs to the calculator.

Any possibility that there was not the correct amount of grain?

 

[rtstrider]

I'm a little lost on this. 58% efficiency is so low it would be hard to achieve if you tried. You would need to collect almost twice as much wort as the recipe calls for or have almost no crush on the grains.

I think this is a calculation error. Something is not right in the inputs to the calculator.

Any possibility that there was not the correct amount of grain?

Bear in mind this was a hefty grain bill. It was around 15lbs. That 58% is brewhouse efficiency. My numbers that I put in the calculator have been off so it look to be an error on my part. I've taken the time over the past week to notate boil off loss per hour, mash tun loss, etc. My issue appears to be I may have been diluting the grains (aka using much less grains than I should be) and essentially overdiluting the wort. I have put in the numbers for the next few brews to see if that fixes this. The next brew is Friday and that's an 11lb brew so it may not be the best benchmark here. I'll still take pictures and post an update with the gravity and such. Decided the brews after that are going to be to low abv brews to help fine tune the system a bit. I'll make sure to post updates on here in hopes it may possibly help someone else with the same issues.

 

[kh54s10]

Bear in mind this was a hefty grain bill. It was around 15lbs. That 58% is brewhouse efficiency. My numbers that I put in the calculator have been off so it look to be an error on my part. I've taken the time over the past week to notate boil off loss per hour, mash tun loss, etc. My issue appears to be I may have been diluting the grains (aka using much less grains than I should be) and essentially overdiluting the wort. I have put in the numbers for the next few brews to see if that fixes this. The next brew is Friday and that's an 11lb brew so it may not be the best benchmark here. I'll still take pictures and post an update with the gravity and such. Decided the brews after that are going to be to low abv brews to help fine tune the system a bit. I'll make sure to post updates on here in hopes it may possibly help someone else with the same issues.

Keep at it. There is error somewhere in measurements. I routinely brew grain bills of that amount and more and have never gone below 65%

 

[rtstrider]

Just pitched the yeast. Wanted to let everyone know I got about 4% better efficiency than I was shooting for! Ended up with 74% brew house efficiency. Looks like I was overfilling they boil pot with wort so it wasn’t boiling off enough to hit my projected og. I also mashed for 90 minutes today so not sure if that helped. Mash temp was 150f. Anywho can’t wait till next brew!