Dang, I'm Good: 103% Conversion....

Nosybear said:
I never have taken first running readings and suspected something like this might be the problem. I guess I can start, just so I have the statistics on my brews. I also suspected I might need to in order to use the function.
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The conversion is measuring the sugar in the mash, before sparging, so if you want to know your conversion you need to measure the gravity prior to sparging.

Nosybear said:
Enter all MASH ONLY liquor for the volume.
Enter the FIRST RUNNINGS ONLY gravity for the gravity.
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Correct, enter the water volume used for mash infusions prior to the first runnings. Strike steps, infusions if you do so. Decoctions are going to through it off slightly since you're evaporating the wort some and concentrating the wort into a smaller volume (raising the SG).

The system will calculate sugars left in the mash tun using the grain absorption and dead space.

Nosybear said:
Devil's advocate question: What if we add simple sugars to the mash? Does the system know enough to compensate for that? Or if we, as some have done, mash in with maple sap?
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It shouldn't matter, if it does then that's a bug. Conversion should only apply to mashed fermentables. Anything that's not a grain, or is a late addition, shouldn't affect conversion.
 
Mark Farrall said:
Is there some assumption of there being a sparge? I'll get the odd low 100% conversion reading and I'm nearly always doing full volume mashes. I know Ben also mashes pretty thin.
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Shouldn't matter. The only thing it's doing is calculating the total sugar potential of the grain bill, and comparing it to what you say you have in the wort according to the brew log entry.

Whether it's 3.75 gallons of water used to mash, with a gravity of 1.0709, and the remaining 2.36 gallons is sparged, or I use the whole 7.61 gallons with a gravity of 1.0509, it's the same amount of sugar, and the same conversion efficiency.
 
Pricelessbrewing said:
I already have a ticket to clarify the tooltip in the brew session, and update the documentation so that it matches.

For conversion efficiency you must enter all mash infusions, strike/infusions, but not sparges, and the gravity reading again must be taken prior to any sparges. This could be literally inside the mash, or it could be the runoff from the mash prior to sparging. Either should be the same. Stirring to ensure homogeneous gravity is highly recommended.

Any efficiency calculation is only as accurate as your volume and grain bill. If you're eyeballing it, and are off by a quarter gallon, well that corresponds to a 10% difference in volume and is the difference between getting 101% instead of 92% conversion. If your grain bill information is off, either in measured weight of each grain, or the PPG, then that also introduces an error bar. If your base malt is 36 ppg instead of 37 ppg that makes a difference as well.

It looks like @Nosybear and @Trialben you're both entering preboil gravities instead of mash gravities, prior to sparging, and are including the sparge volume in the mash complete volume log.
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Ah thankyou yes exactly cheers yes when calculating conversion I've been taking a sample at the end of mash and Sparge and using this (total brew liquor volume) to calculate conversion efficiency. LIGHT BULB MOMENT CHEERS!

So just so I get it I need to take a gravity sample of the wort before I sparge and use this as my conversion efficiency.
So if I take the sample after sparging but deduct sparge volume from total liquor I guess wouldn't get me near enough to conversion efficiency ?

I can imagine this will be more easily achieved with a Refractometer than the hydrometer way I use.
It'll be a PITA to take a conversion sample pre sparge and then a pre boil sample post sparge i guess as i have been, i'll just use the preboil gravity as an indicator how I'm tracking on brew day.

Thanks again pricelss for taking the time to go through this with us it's explained the constant 100+ conversion efficiencys.
 
Trialben said:
Ah thankyou yes exactly cheers yes when calculating conversion I've been taking a sample at the end of mash and Sparge and using this (total brew liquor volume) to calculate conversion efficiency. LIGHT BULB MOMENT CHEERS!

So just so I get it I need to take a gravity sample of the wort before I sparge and use this as my conversion efficiency.
So if I take the sample after sparging but deduct sparge volume from total liquor I guess wouldn't get me near enough to conversion efficiency ?

I can imagine this will be more easily achieved with a Refractometer than the hydrometer way I use.
It'll be a PITA to take a conversion sample pre sparge and then a pre boil sample post sparge i guess as i have been, i'll just use the preboil gravity as an indicator how I'm tracking on brew day.

Thanks again pricelss for taking the time to go through this with us it's explained the constant 100+ conversion efficiencys.
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Ben, if you use a hydrometer, just dump the sample back in. You're going to boil it anyway....
 
Trialben said:
So just so I get it I need to take a gravity sample of the wort before I sparge and use this as my conversion efficiency.
So if I take the sample after sparging but deduct sparge volume from total liquor I guess wouldn't get me near enough to conversion efficiency ?
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Correct.

The issue is that sparging does more than change the volume, you're diluting the wort that's stuck in the grain and mixing it with water. So you're gaining sugars. That's the entire purpose of sparging, otherwise you could just add water directly to the preboil volume. Since conversion is a measurement of the sugar in the mash, adding sugars and volume from the sparge throws that off.

There's a batch sparge prediction formula I created a couple years ago that does an good approximation for no sparge, and ideal batch sparges. But it introduces maybe 5% error when using for measurements, and I need to know exactly what your equipment settings are. I can use it for my system because I know my volumes and absorptions very accurately.
 
Pricelessbrewing said:
Correct.

The issue is that sparging does more than change the volume, you're diluting the wort that's stuck in the grain and mixing it with water. So you're gaining sugars. That's the entire purpose of sparging, otherwise you could just add water directly to the preboil volume. Since conversion is a measurement of the sugar in the mash, adding sugars and volume from the sparge throws that off.

There's a batch sparge prediction formula I created a couple years ago that does an good approximation for no sparge, and ideal batch sparges. But it introduces maybe 5% error when using for measurements, and I need to know exactly what your equipment settings are. I can use it for my system because I know my volumes and absorptions very accurately.
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I think what you have pointed out makes the light bulb go on with lots of us. If you go to FAQ's for conversion it gives you 2 options for calculating. 1 includes sparge water (be sure to stir it well). So am I correct in stating maybe for clarification this needs updated to match the calculations now used ?
 
Head First said:
I think what you have pointed out makes the light bulb go on with lots of us. If you go to FAQ's for conversion it gives you 2 options for calculating. 1 includes sparge water (be sure to stir it well). So am I correct in stating maybe for clarification this needs updated to match the calculations now used ?
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Yup. I've raised that point with the developers multiple times. I just got access to edit the documentation myself so updating the documentation page and the tooltips is on my own to-do list now.
 
Pricelessbrewing said:
Yup. I've raised that point with the developers multiple times. I just got access to edit the documentation myself so updating the documentation page and the tooltips is on my own to-do list now.
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Thank you sir, this will do more to help novice brewers become better brewers than penny counting or world wide flags on malts :D. Please carry on.
 
Pricelessbrewing said:
@Nosybear @Head First @Trialben @Yooper

If you have a spare minute, could you take a look at the changes I made to https://docs.brewersfriend.com/faq/brew-sessions#mashcomplete and see if that makes more sense. I've removed the A/B options for blends of runnings and (hopefully) clarified things further.

I haven't figured out where the tooltip text is in the actual brew log yet, so I'll need a hand to correct that next.
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I'd make "volume" read something like "the sum of the strike water and all infusions prior to sparging," or something similar.
 
Nosybear said:
I'd make "volume" read something like "the sum of the strike water and all infusions prior to sparging," or something similar.
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Thanks that sounds much better. Was definitely struggling with how to phrase it coherently.
 
Makes sense to me. Will change lots of recipe conversion efficiencys for me. When i did make entries in the brew log i used total preboil volumes most of the time. Could you please point out the date of the calculation change? Or are the calculations the same as allways was used, with first runnings being acurate for conversion efficiency. And then preboil volumes which include sparge being inaccurate for conversion efficiency?
 
Head First said:
Makes sense to me. Will change lots of recipe conversion efficiencys for me. When i did make entries in the brew log i used total preboil volumes most of the time. Could you please point out the date of the calculation change? Or are the calculations the same as allways was used, with first runnings being acurate for conversion efficiency. And then preboil volumes which include sparge being inaccurate for conversion efficiency?
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The description was changed for the volume to go to "water volume" was made 7 months ago according to the timestamp on the updates merge. But the documentation and tooltip was never updated.

The calculation never changed afaik, at least not as long as I've worked with bf, but the text has always been inaccurate for the previously mentioned reasons.

When I update the tooltip and finish the documentation I'll post in the changelog.
 
Pricelessbrewing said:
The description was changed for the volume to go to "water volume" was made 7 months ago according to the timestamp on the updates merge. But the documentation and tooltip was never updated.

The calculation never changed afaik, at least not as long as I've worked with bf, but the text has always been inaccurate for the previously mentioned reasons.

When I update the tooltip and finish the documentation I'll post in the changelog.
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That might explain why a few of us were using Total water volume including any sparge volume for the conversion calculation.
Hey I went back a changed a few of my brew log entries conversion logs and deducted the sparge volume and they dropped to around 95~% so not as accurate as taking a sample before sparge but close enough for me.

You know if was thinking (dangerous I know) but with this conversion efficiency thing. You said take a sample before sparging for your conversion efficiency which will be a more dense wort just not as diluted yet with sparge water.
I'm not sure it would make that great a difference just sparging rinsing them remaining sugars off the grain then taking my wort sample as previously?

My sparge is only 5lt I guess compared to a more thick mash were more sparge water will be used the differences in conversion gravity and preboil gravity would be quite different.
 
I couldnt remember the date but I do remember that things were changed and tgere was discussion at that time. At that time i mostly quit using the brew log as I knew approximately the numbers i was going to get anyway. Thanks @Pricelessbrewing for rewriting the faqs to help clarify this.
 
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Trialben said:
That might explain why a few of us were using Total water volume including any sparge volume for the conversion calculation.
Hey I went back a changed a few of my brew log entries conversion logs and deducted the sparge volume and they dropped to around 95~% so not as accurate as taking a sample before sparge but close enough for me.

You know if was thinking (dangerous I know) but with this conversion efficiency thing. You said take a sample before sparging for your conversion efficiency which will be a more dense wort just not as diluted yet with sparge water.
I'm not sure it would make that great a difference just sparging rinsing them remaining sugars off the grain then taking my wort sample as previously?

My sparge is only 5lt I guess compared to a more thick mash were more sparge water will be used the differences in conversion gravity and preboil gravity would be quite different.
Click to expand...

Sparging isn't just diluting the sugars from the first runnings, the sparge water is also "absorbing" sugars from the grainbed. If your conversion was ~95% with the preboil gravity sample, and without sparge volume, then your conversion was likely ~88 or so. Just spitballing some numbers, I'd have to know more about your equipment and losses to give more accurate approximations.

An analogy I've used before is this. Pretend the grains are a big sponge, and the sugars you're adding from the mash is just sugars.

Lets say you're adding 10 lbs of sugar (about the same as 12 lbs of grain) to 6 gallons of water. The sugars increase the sugar water volume by 0.74 gallons. The grains absorb ~2.25 gallons of that sugar water like a huge sponge, now your apparent absorption rate is still only 1.5 gallons since you're not counting the increase of 0.74 gallons from the sugar.

So your first runnings will be approximately 4.5 gallons of 1.068 SG. You've recovered 6.66 lbs of sugar.

There's still 3.33 lbs of sugar "stuck" in the 2.25 gallons of sugar water absorbed in the grains. When you sparge with 1.25 gallons, you're diluting the 2.25 gallons with the 1.25 gallons of sparge water, bringing the whole sparge "mash" sg down to 1.044. You're recovered another 1lb of sugar from doing a sparge.

Not sure if that helped or just made it more confusing. o_O
 
Pricelessbrewing said:
Sparging isn't just diluting the sugars from the first runnings, the sparge water is also "absorbing" sugars from the grainbed. If your conversion was ~95% with the preboil gravity sample, and without sparge volume, then your conversion was likely ~88 or so. Just spitballing some numbers, I'd have to know more about your equipment and losses to give more accurate approximations.

An analogy I've used before is this. Pretend the grains are a big sponge, and the sugars you're adding from the mash is just sugars.

Lets say you're adding 10 lbs of sugar (about the same as 12 lbs of grain) to 6 gallons of water. The sugars increase the sugar water volume by 0.74 gallons. The grains absorb ~2.25 gallons of that sugar water like a huge sponge, now your apparent absorption rate is still only 1.5 gallons since you're not counting the increase of 0.74 gallons from the sugar.

So your first runnings will be approximately 4.5 gallons of 1.068 SG. You've recovered 6.66 lbs of sugar.

There's still 3.33 lbs of sugar "stuck" in the 2.25 gallons of sugar water absorbed in the grains. When you sparge with 1.25 gallons, you're diluting the 2.25 gallons with the 1.25 gallons of sparge water, bringing the whole sparge "mash" sg down to 1.044. You're recovered another 1lb of sugar from doing a sparge.

Not sure if that helped or just made it more confusing. o_O
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Yeah totally get that beauty about Biab you can give that sponge a Squeeze;).
Thanks again brings it into perspective cheers.
 
If anyone's curious, I went through all of the brew day related log entries, all of the mash complete, boil, and brew day complete entries and cleaned them up and clarified.

Feel free to review it on the beta site, https://beta.brewersfriend.com/homebrew/mybrewing,

and the FAQ section of the documentation. https://docs.brewersfriend.com/faq/brew-sessions#mashcomplete

For comparisons sake, I left the Brew session / Brew log section of the documentation as it was. I will update it once this goes live.

https://docs.brewersfriend.com/brew-session/brew-log

I also plan on updating the brewing efficiency chart, and writing a new article on efficiencies to help set things straight.

 
The update for this has gone live. Let me know if you still have any questions or see any issues!
 
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