Help figuring out PBG from first runnings

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olotti

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This is all grain. I've been doing 90 min mash rests with no mash out and dble batch sparging and while my efficiency has been great the really fermentable wort has crushed my fg's in my last few beers dropping them 5,7,even one 9 points low on my FG, thereby really drying out the beer and adding bitterness
Which I obviously don't want. After doing research I now realize it was the long mash plus letting the runoff sit while sparging that was creating this highly fermentable wort. So next batch I want to do the same with a no mash out but only mash rest for 60 min so I want to see if my efficiency will suffer and if I'll hit my pre boil gravity and I thought you could do that by the sample from the first runnings and basically extrapolating that out but I'm not sure how. Any ideas? Thanks.
 
Buy a refractometer, probably. I thought a 90-minute mash was pointless...I better get back to reading.
 
A 90 min. mash will give you a slightly more fermentable wort. But I'm curious what you're comparing your FG to. Software predictions are notoriously inaccurate. The best way to cure a low FG is through the recipe. Mash temp doesn't have as much effect as previously thought. Your double batch sparge isn't helping, either. Have you ever tried a single to compare? I've found that more than one batch sparge addition makes so little difference that it's not worth my time. I get between 83-85% efficiency by using a loose mash ration (1.65-75 qt./lb.) and doing a single sparge addition. Try that and see if it works for you. The shorter time during the sparge could help with your attenuation problem.

I'm not exactly sure what you're getting at with the sampling first runnings to check pre boil gravity. About the only thing you can deduce from first runnings is conversion efficiency. http://braukaiser.com/wiki/index.ph..._Efficiency#Determining_Conversion_Efficiency
 
Buy a refractometer, probably. I thought a 90-minute mash was pointless...I better get back to reading.

I use a refractometer. I always check my pre boil gravity as I collect my last sparge this way I make sure Im going to hit my pre boil gravity and not drain to much. But is there a way to say, ok my preboil volume should be say 1.065 so at first running I should have "x gravity reading", after first sparge my gravity should be "x" and at final collection I should have 1.065 so u kind of track the gravity reading as you collect the wort so u know if your on the right track to hitting your PBG.
 
A 90 min. mash will give you a slightly more fermentable wort. But I'm curious what you're comparing your FG to. Software predictions are notoriously inaccurate. The best way to cure a low FG is through the recipe. Mash temp doesn't have as much effect as previously thought. Your double batch sparge isn't helping, either. Have you ever tried a single to compare? I've found that more than one batch sparge addition makes so little difference that it's not worth my time. I get between 83-85% efficiency by using a loose mash ration (1.65-75 qt./lb.) and doing a single sparge addition. Try that and see if it works for you. The shorter time during the sparge could help with your attenuation problem.

I'm not exactly sure what you're getting at with the sampling first runnings to check pre boil gravity. About the only thing you can deduce from first runnings is conversion efficiency. http://braukaiser.com/wiki/index.ph..._Efficiency#Determining_Conversion_Efficiency

Thanks for the thoughts, as I look back I think my beers were better when I just started out last year and then I was doing a 60 min mash with a single sparge, so I think that I may get back to that and to save time and cut down the time the wort sits before being hit with the sparge collections. I pretty much always use 1.33qts/lb to calculate my mash water, no real reason it's just seemed to work but maybe this next batch on Tuesday I'll try a looser mash ratio, single sparge it and see what my efficiency clocks in at.

Oh I use beersmith for my recipe formulations and I'm fine with a FG thats 1-2 points low but being 5,7,9 points low is definitely detectable in the final product.
 
Thanks for the thoughts, as I look back I think my beers were better when I just started out last year and then I was doing a 60 min mash with a single sparge, so I think that I may get back to that and to save time and cut down the time the wort sits before being hit with the sparge collections. I pretty much always use 1.33qts/lb to calculate my mash water, no real reason it's just seemed to work but maybe this next batch on Tuesday I'll try a looser mash ratio, single sparge it and see what my efficiency clocks in at.

Oh I use beersmith for my recipe formulations and I'm fine with a FG thats 1-2 points low but being 5,7,9 points low is definitely detectable in the final product.

Brad Smith is a great guy and a good friend, but that doesn't mean I believe the FG predictions in Beersmith. Really, the only way to know what FG to expect is through the experience of repeatedly brewing a recipe.
 
A 90 min. mash will give you a slightly more fermentable wort. But I'm curious what you're comparing your FG to. Software predictions are notoriously inaccurate. The best way to cure a low FG is through the recipe. Mash temp doesn't have as much effect as previously thought. Your double batch sparge isn't helping, either. Have you ever tried a single to compare? I've found that more than one batch sparge addition makes so little difference that it's not worth my time. I get between 83-85% efficiency by using a loose mash ration (1.65-75 qt./lb.) and doing a single sparge addition. Try that and see if it works for you. The shorter time during the sparge could help with your attenuation problem.

I'm not exactly sure what you're getting at with the sampling first runnings to check pre boil gravity. About the only thing you can deduce from first runnings is conversion efficiency. http://braukaiser.com/wiki/index.ph..._Efficiency#Determining_Conversion_Efficiency
I'll be honest, I did not know the time during the sparge had any effect on the beer. I'm off to google.

I use a refractometer. I always check my pre boil gravity as I collect my last sparge this way I make sure Im going to hit my pre boil gravity and not drain to much. But is there a way to say, ok my preboil volume should be say 1.065 so at first running I should have "x gravity reading", after first sparge my gravity should be "x" and at final collection I should have 1.065 so u kind of track the gravity reading as you collect the wort so u know if your on the right track to hitting your PBG.

I see what you mean now. I don't know if there is a formula to deduce what you want.
 
Think about it..during the sparge, you're still in the temp range for conversion. I use 185-195F sparge water, which puts the grain bed temp in the mashout area.
 
I've been having super low FGs too lately, I think I take too long to sparge trying to get the wort clear through vorlaufing and that also cools the wort to let the Beta Amylase go nuts. I've been trying a combo of super hot mash out and boiling the first runnings while sparging on certain styles (always did this on Scotch ales, started on some lagers, porters, stouts, etc.). I haven't gone through enough to figure out if it's helping yet.
 
Think about it..during the sparge, you're still in the temp range for conversion. I use 185-195F sparge water, which puts the grain bed temp in the mashout area.

I'm midway through that link you provided. It does make a lot of sense. I mash at 152 a lot. I do 60 minute mashes and then sparge with 168F water. So I am still within limits of conversion and it does show how attenuation is affected. I also see that there is a weird sweet spot, perhaps due to theory of "sprinting" where a very high mash temp and a 280 minute mash (beginning to end of sparge) results in higher attenuation.


It is all so interesting and I never gave it any thought. It's actually kind of rad.

Sorry for hijacking your thread OP.
 
I'm midway through that link you provided. It does make a lot of sense. I mash at 152 a lot. I do 60 minute mashes and then sparge with 168F water. So I am still within limits of conversion and it does show how attenuation is affected. I also see that there is a weird sweet spot, perhaps due to theory of "sprinting" where a very high mash temp and a 280 minute mash (beginning to end of sparge) results in higher attenuation.


It is all so interesting and I never gave it any thought. It's actually kind of rad.

Sorry for hijacking your thread OP.

No prob. Yeah I didn't realise all this was going on either I just thought I was getting great attenuation from healthy yeast starters until like 5 beers in a row bottomed out on the FG then I had to re look at my process. After some reading I realized that with a 90 min mash then vorlouf then collectin then waiting after the sparge then vorlouf and collecting my initial first runnings would sit for 30 extra minutes denaturing in the kettle before being hit with the hotter sparge water. My 90 min mash turned into a 120 min mash when it was all said and done.
 
I'm midway through that link you provided. It does make a lot of sense. I mash at 152 a lot. I do 60 minute mashes and then sparge with 168F water. So I am still within limits of conversion and it does show how attenuation is affected. I also see that there is a weird sweet spot, perhaps due to theory of "sprinting" where a very high mash temp and a 280 minute mash (beginning to end of sparge) results in higher attenuation.


It is all so interesting and I never gave it any thought. It's actually kind of rad.

Sorry for hijacking your thread OP.

No prob. Yeah I didn't realise all this was going on either I just thought I was getting great attenuation from healthy yeast starters until like 5 beers in a row bottomed out on the FG then I had to re look at my process. After some reading I realized that with a 90 min mash then vorlouf then collectin then waiting after the sparge then vorlouf and collecting my initial first runnings would sit for 30 extra minutes denaturing in the kettle before being hit with the hotter sparge water. My 90 min mash turned into a 120 min mash when it was all said and done and you can imagine mashing at 149-150 to begin with plus the extra conversion really threw off the FG, it basically stripped the hops out of the beer is was so bitter and dry. Ya live and learn.
 
I use a refractometer. I always check my pre boil gravity as I collect my last sparge this way I make sure Im going to hit my pre boil gravity and not drain to much. But is there a way to say, ok my preboil volume should be say 1.065 so at first running I should have "x gravity reading", after first sparge my gravity should be "x" and at final collection I should have 1.065 so u kind of track the gravity reading as you collect the wort so u know if your on the right track to hitting your PBG.

You might want to look at Kai's batch sparge simulator. I think it does the kind of calculations you are asking about (or at least something that you might be able to adapt.)

Brew on :mug:
 
You might want to look at Kai's batch sparge simulator. I think it does the kind of calculations you are asking about (or at least something that you might be able to adapt.)

Brew on :mug:

Cool thanks. I think I'll prob try what Denny suggested and do a thinner mash for 75 min with one sparge and see what happens with that for my ipa on Tuesday. If anything it should save time
 
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