evaluating conversion efficiency

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teach

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Anybody have much experience dealing with efficiency problems in the conversion, not the lauter?

Thanks to Kaiser's Troubleshooting Brewhouse Efficiency, I think the source of my ~65% brewhouse efficiency might actually be in my conversion, not the lauter/sparge.

My most recent brewday, I started with 10 lbs of 2-row, which I mashed with 4 gallons of water (1.6 qts/lb). I mashed for 90 minutes at 152F.

I ran off 3-1/2 gallons of first runnings, which I measured at 1.059. If I calculate correctly, this gives me a conversion efficiency of ~78%, way worse than the 95% I ideally should be getting.

Am I figuring that right? Suggestions?

I don't have a mill, so I'm at the mercy of AHS' default crush.

I did *not* mash out or add any water to the MLT, so the temperature was not raised anywhere near 170F for my first runnings. Maybe this would make a difference?
 
I believe your calculations are correct. I would look at mash pH, and grind. Another possibility, although improbable, is inaccurate temperatures. Are you checking for conversion with an iodine test?
 
I don't really have much control over the grind, but I can pick up some Five Star 5.2 for my next mash and see how that goes.

Also, I'll have my thermometer checked; it could very well be off.

Thanks for the suggestions!
 
Eek. That's a fair bit more involved than I want to mess with. Guess I'll just live with the low conversion for now. Thanks for all the help, though.
 
It's not as bad as it looks, really. At the very least, get a water report either through your utility company or you can order on at wardslab.com for 20 bucks. Then you'll know where you stand as far as water and pH is concerned.
 
I had my friend in a chemistry lab test the pH of the filtered water I was using to brew with: it's got a pH of ~8.2. So I already add CaCl (1 tsp per 5 gallons) to the brew water.

I don't know the mash pH, though.
 
I don't know the mash pH, though.

..but that's the important thing. Your water pH just tells you the ion ratio, but not the magnitude. Imagine a seesaw; 1lb:2lb is the same ratio as 10lb:20lb, but it takes ten times as much to balance the latter.

CaCl2 will lower pH, but you only want so much chloride. You can bring down your mash pH with minerals, sauer malt, roasted grains, an acid rest, diluting with RO/distilled water, or straight up acid. Test with these:
4.6-6.2-pH-Test-Strips-th.jpg

Disclaimer: Never listen to strangers on the interwebs.:cross:
OBTW, no need to send in to Ward. Lotsa brewers in Austin can tell you how to treat the water there. Great subject to bring up at a Zealots meet.
 
I have heard that TX is know for it's highly alkaline water. I'd get a water test and start adjusting with salts. With the EZ spreadsheet it's so EZ, any fool can do it.

I bet your water makes great stouts but can't make a light colored beer without adjustments.

Don't be afraid of water adjustment, it's really much EZier then it looks.


FYI: My first runnings are always in the 1.080 range when mashing at 1.25 - 1.33 qts/lb
 
Thanks to Kaiser's Troubleshooting Brewhouse Efficiency, I think the source of my ~65% brewhouse efficiency might actually be in my conversion, not the lauter/sparge.

I've looked at conversion potential in the past for my OWN efficiency problems and i can't seem to get past one idea - theoretical 100% potential extract. i understand getting the ~78% conversion efficiency calculated in the OP's scenario, but what about when a significant portion of the grist is made up of grains with potential sugars lower than 2-row? How does that change the equation? In that instance, the chart provided by Kai for "Mash Thickness -> 100% Theortical SG" (chart) should be adjusted, shouldn't it?

I don't sound clear even to myself, but if I've got two mashes at the same mash thickness (1.6qt/lb) with two different grists of:

Grist 1 = 10lbs of 2-row (36pppg)
Grist 2 = 5lbs of 2-row (36pppg) + 5lbs of Munich (33pppg),

to me, common sense says that the potential for the two grists should be different. What does THAT equation look like?
 
I've looked at conversion potential in the past for my OWN efficiency problems and i can't seem to get past one idea - theoretical 100% potential extract. i understand getting the ~78% conversion efficiency calculated in the OP's scenario, but what about when a significant portion of the grist is made up of grains with potential sugars lower than 2-row? How does that change the equation? In that instance, the chart provided by Kai for "Mash Thickness -> 100% Theortical SG" (chart) should be adjusted, shouldn't it?

Yes, the chart that he posted is based on a grist with 80% extract and 4% moisture, or ~1.036. A more exact method would be to calculate the potential extract for your specific grist and moisture content, but the chart is fairly close most of the time. The '100% conversion' value is calculated the same way you would calculate a refractometer reading:

G = mass sugar / (mass sugar + mass water)

Here you get the mass of sugar from the malt analysis sheet. Lets say your malt sheet specifies 80% yield FGDB and 4% moisture. That '% yield' is the % by mass of sugar yielded by mashing that malt. So if you mash 5 kg of that grain, you'd get .8*5=4 kg of extract. You also need to adjust for moisture, since when you weigh out the grain 4% of that will be water. So the true yield in the mash is 4 kg * (100-4)% = 3.84 kg.

If you don't have the analysis sheet, you can convert from the points*gal/lb figure by taking a ratio to the yield of sucrose: 46.214 points*gal/lb. So if your grain is 36 points*gal/lb, the % yield is 36/46.214 = 77.9%. Again as before, mashing 5 kg of this malt would yield 5*.779=3.89 kg. These figures are usually already moisture corrected, so don't worry about that.

Next we have the mass of the water, which is easy if we are working in metric units since water is roughly 1 kg/L. You can do this in English units too, just make sure you do it by weight (water weighs ~8 lbs/gal).

I don't sound clear even to myself, but if I've got two mashes at the same mash thickness (1.6qt/lb) with two different grists of:

Grist 1 = 10lbs of 2-row (36pppg)
Grist 2 = 5lbs of 2-row (36pppg) + 5lbs of Munich (33pppg),

to me, common sense says that the potential for the two grists should be different. What does THAT equation look like?

So in your example

grist 1
10 lbs of 2-row (4.55 kg) @ 36 p*gal/lb (36/46.214 = 77.9%)
mash volume: 16 qt (15.1 L)

mass sugar = .779*4.55 = 3.54 kg
mass water = 15.1 kg
G1=mass sugar / (mass sugar + mass water)
G1 = 3.54 / (3.54 + 15.1) = 19% ==> this is the refractometer reading in Brix. A quick conversion to SG is 259/(259-°B) = 1.084

grist 2
5 lbs (2.27 kg) @ 36 p*gal/lb (77.9%) and 5 lbs @ 33p*gal/lb (33/46.214=71.4%)
mash volume = 16 qt (15.1L)

mass sugar = .779*2.27 + .714*2.27 = 3.39 kg
mass water = 15.1 kg
G2 = mass sugar / (mass sugar + mass water)
G2 = 3.39 / (3.39 + 15.1) = 18.3%, or 1.076
 
You're only losing 1/2 gallon of water to grain absorbtion with 10lbs of grain? How are you measuring volume?

Extremely poorly.

I've got an electric HLT made from a 10-gallon Rubbermaid cooler that has graduations inside, so I use that to figure, roughly, how much water I'm putting into the mash tun initially.

Then, after the mash time is over, I vorlauf and then drain into an unmarked 7-gallon bottling bucket. Based on how full it gets, I've got some idea of how much I collected, but it's quite likely to be plus or minus half a gallon. Not to mention that hot wort has a different volume than room-temperature wort, and I'm not correcting for that, either.

I do now have a bucket fermenter with real markings on the side that I'll be using for my next batch, but I bought it after my last brewday.
 
Anybody have much experience dealing with efficiency problems in the conversion, not the lauter?

I don't have a mill, so I'm at the mercy of AHS' default crush.

I did *not* mash out or add any water to the MLT, so the temperature was not raised anywhere near 170F for my first runnings. Maybe this would make a difference?

Most likely your low conversion is due to the crush at the LHBS. They tend to be fairly wide so that the grist lauters well on anybody's system, and consequently the gap isn't fine enough to expose all the available endosperm to water for conversion. The easiest way to solve this problem is to grind finer, but if you can't do that then decoctions will help or mashing for a much longer time (like overnight).

I'm not sure about the effect of a mashout on brewhouse efficiency. I've been recording the 60 min mash gravity and the mashout gravity on the last dozen batches or so, and the gravity is nearly always higher after a mashout. But I don't know if a non mashed-out beer would get that same starch in the kettle and just convert it there as it is heated to a boil, or if the starch must first be gelatinized to make its way out?

Mash pH could also be an issue as was already mentioned. The simplest way to do it is check the pH after dough in with reliable pH strips, adjust with food grade acid, and check again. You'll find that the pH usually needs to be adjusted down, especially if your water is alkaline. Kai has an article on the colorpHast strips, check those out for a reliable measuring method.
 
Extremely poorly.

I've got an electric HLT made from a 10-gallon Rubbermaid cooler that has graduations inside, so I use that to figure, roughly, how much water I'm putting into the mash tun initially.

Then, after the mash time is over, I vorlauf and then drain into an unmarked 7-gallon bottling bucket. Based on how full it gets, I've got some idea of how much I collected, but it's quite likely to be plus or minus half a gallon. Not to mention that hot wort has a different volume than room-temperature wort, and I'm not correcting for that, either.

I do now have a bucket fermenter with real markings on the side that I'll be using for my next batch, but I bought it after my last brewday.

IMO you can't accurately measure efficiency (and troubleshoot problems) until you are accurately measuring volume, temperatures, and gravities.

Also, you should check the markings on your ale pail. They are notoriously off.

I too had efficiency "problems" until I started taking my measurements more seriously. My conversion efficiency "jumped" to 88% based solely on accurate measurements.
 
IMO you can't accurately measure efficiency (and troubleshoot problems) until you are accurately measuring volume, temperatures, and gravities.

Yeah, but the gravity of my first runnings was 1.059 (and I'm certain of that). It doesn't matter whether that's 2-1/2 gallons or four gallons; there's a problem with conversion.

And I know my brewhouse efficiency is basically correct; I measure my final volume of collected wort (post-boil) very well. I just can't (currently) measure hot wort on the brewday so accurately.
 
Yeah, but the gravity of my first runnings was 1.059 (and I'm certain of that). It doesn't matter whether that's 2-1/2 gallons or four gallons; there's a problem with conversion.

And I know my brewhouse efficiency is basically correct; I measure my final volume of collected wort (post-boil) very well. I just can't (currently) measure hot wort on the brewday so accurately.

good points -

Maybe try mashing a little thinner? I recently have gone to ~2qt/lb and did see a bit of a jump in conversion efficiency.
 
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