2 Vessel Mash Efficiency very low.. Help?

[bodhi314]

I have sorted through the low efficiency threads I can find, but am a little bugged with my mash lately.

I have a version of this:
https://www.homebrewtalk.com/f51/countertop-brutus-20-a-131411/

Only mine is 2 keggles on two burners, run manually with two pumps.
I based the idea off of Lonnie Mac's Rev 2 of the Brutus...
I am hitting mash temp, time, volumes - and controlling mash pH with 5.2.
My efficiency 2 brews this week = ~50%

Two questions:

1) Can adjusting mill gap (Barley Crusher) make up for this much inefficiency?
(-- mine is still set at factory gap)

2) I use San Diego tap water, run through a carbon filter - will adding brewing salts (which?) increase efficiency?

Two brews in a row I've had to bring up with DME, not ideal!

Any other ideas are welcome too - and I'd be glad to field any specific questions to get some idea which direction to head now...

Thanks in advance - Thomas

 

[BendBrewer]

I don't know about your system but that 5.2 always screwed with me. Well it screwed me twice then I threw it away. A have a basic single tier.

 

[bodhi314]

Can you give a little more detail? Was it lowering your efficiency?

I was trying to keep the husk tannin from getting pulled out (astringent) in the longer cross-sparge.

Cheers (and nice setup).

 

[BendBrewer]

Thanks.

Yeah it killed my efficiency, like 20 points. At least that is what I blamed it on both times. Got rid of it and the problem.

Have read that others on here have had similar bad experiences with the stuff. Not saying that is your problem but I think it was mine.

 

[jkarp]

I was trying to keep the husk tannin from getting pulled out (astringent) in the longer cross-sparge.

Length of recirculation isn't going to add astringency unless you go nuts and raise the temp above 170F.

Give me a little more to go on like your recipe, temps and water volumes. I've found my Brutus 20 efficiency calculations to be extremely predictable.

 

[manoaction]

I saw a water chemistry report for San Diego over here, and rather than focusing solely on mash ph, you should probably run things through the EZ water calculator sheet in the chemistry forum.

The San Diego water website has a report with some info, and you can use the post I linked to for the fill in anything missing.

It looks like you might need to add some calcium cloride to balance your sulfate ratio, but other than that your water seems pretty good.

 

[bodhi314]

Length of recirculation isn't going to add astringency unless you go nuts and raise the temp above 170F.

Give me a little more to go on like your recipe, temps and water volumes. I've found my Brutus 20 efficiency calculations to be extremely predictable.

@ jkarp:
two recipes same efficiency 50-55%
1(8# Maris Otter)
2(11# 2row, 0.25# 40L, 0.75# carapils)
Both for 5.5 gal into primary

Mash at 152 for 75 minutes, mash out to 168, and cross sparge until both vessels read the same on refractometer - then turn off return from BK. And fire up boil....

Yesterday, my mash gravity was 1.088 - pre-boil was 1.037! (-target pre-boil 1.054)
Added 1.5# DME to boil to bring back up to target of 1.070 (with 0.75# dextrose per recipe - Pliny Bastid Clone).
My mash-in volume was 3.5 gal, cross sparge with 5.6 gal - total volume into BK was 7 gal - 90 min boil to 5.5 into fermenter.

Am I giving you the needed details?

 

[bodhi314]

I saw a water chemistry report for San Diego over here, and rather than focusing solely on mash ph, you should probably run things through the EZ water calculator sheet in the chemistry forum.

The San Diego water website has a report with some info, and you can use the post I linked to for the fill in anything missing.

It looks like you might need to add some calcium cloride to balance your sulfate ratio, but other than that your water seems pretty good.

@manoaction:

Whew - good water -- I need to read up more on the additions, I'll start with CaCL2

 

[jkarp]

OK, let's run the numbers...

If I also assume 0.12 gal/lb absorption, and 0.25 gal deadloss in the MLT, your total system volume of water should have been 8.69 gal.

12lb X 37 = 444 points

So, your max pre-boil gravity would be 1.051. 1.69 gal of this pre-boil wort is lost to absorption and deadloss, so you're really left with 358 gravity points "in the pot".

358 / 5.5 = 1.065 theoretical max OG (80.6% theoretical max Brutus 20 efficiency)

In reality, you'll only see 85% or so of those original 444 points as we don't do congress mashes like the labs. Reworking the math with 377 total points gets:

1.043 pre-boil
1.055 OG (68% efficiency)

Assuming you're getting good conversion, the key point to maximizing Brutus 20 efficiency is minimizing wort losses in the MLT. Design to eliminate deadloss as much as possible. I also continue to runoff throughout the boil and typically see a 0.1 gal/lb absorption rate on my system. These two things alone would give you a 5% bump in efficiency in the above example.

 

[ThePearsonFam]

I saw a water chemistry report for San Diego over here, and rather than focusing solely on mash ph, you should probably run things through the EZ water calculator sheet in the chemistry forum.

The San Diego water website has a report with some info, and you can use the post I linked to for the fill in anything missing.

It looks like you might need to add some calcium cloride to balance your sulfate ratio, but other than that your water seems pretty good.

+1

I Use TH's EZ Water Calc. It's simple to use. I added additional information to convert from weights to teaspoons (since I don't have a scale yet), but I'd stick with weights (ozs) if you have a food scale.

 

[bodhi314]

@JKarp - Awesome man - thank you for running through the TG points.
Somehow it is extremely helpful to see it worked through. Prost.:rockin:

Update:

Last night, started with my mill (barley crusher) - while the tick marks were very similar at noon, the spacing of the rollers was not.
I did not measure the before gaps, but it was clearly more open on one side than the other.

In the end I reset the gap to a tight 0.034 in - the knob on one side was at 2o'clock - on the other side it was at 7 o'clock!

Combined with new calculations I will attempt another brew this weekend to see how we come out.

Updates as available - Cheers!

 

[ThePearsonFam]

Wow... That's a pretty drastic difference. I'd write the manufacturer. Guessing you just used a gap tool to make your adjustments?

 

[bodhi314]

@PearsonFam-

I was a little surprised myself, I'll look into contacting them.

I used a regular gap finder (like used for autos) and stacked a couple to get the wider gap. I had one for each side to make it even. Tightened them until "sticky" when pulling out the finder.

Now I want to motorize that thing (always a list...)

 

[ThePearsonFam]

always