Trying to understand all grain batch sparging

[Denny]

Iodine will tell you if starch is present, but starch conversion to sugar is only part of what we're trying to accomplish. As alpha amylase converts starch to sugar, beta begins breaking the more complex carbohydrates into short chain sugars that are more fermentable. Since these two primary enzymes are most active at different temperatures, we can somewhat control the fermentability of our wort with temp and time. If we only used iodine to tell us the mash is done, we may have a wort that will barely ferment leaving a cloying sweet beer.

+ eleventy billion!

 

[mcfire12]

I ended up mashing my 8.28 pounds of grain with 4.5 gallons of water. Dumped them in my brand new igloo mash tun, water was 162.6 when I added the grain it brought it down to 153.5 so that went about perfect!

Let sit for an hour and took another temp reading... 147.3* that was disappointing after reading most people only lost a degree or 2 at the most. Wonder what the deal was there?

I vorlaufed, then drained the mlt, turned on the heat, then added 3.5 gallon at 168* stirred, let rest maybe a min or 2, then vorlaufed and drained again. Took another reading and it was 1.032, beer smith said it estimated it at 1.037, so I was pretty happy with that. I spent WAY too much time worrying about how that process worked! Hit my estimated pre boil volume and my estimated pre boil gravity almost dead on. But...

Did my 60 min boil and hop addition, business as usual since I have done maybe 6 extract brews. Took another reading after I chilled my wort down to 76* which took about 17 mins with my immersion chiller (that thing works WAY better in the winter when my well water is super cold) I may be building something new for this in the near future. Reading was 1.032 which is the same as my pre boil gravity. That's normal, right??

So beer smith tells me my OG should have been 1.043, how is that possible? How does it go up after the boil? plugged in my numbers to beer smith and it dropped my efficiency down to 53.6% i'm definitely confused on this.

Volume into my fermenter after I drained from my boil kettle was pretty close, but I may need to make some adjustments to my process with this set up, I ended up with 4.75 gallon before I stopped draining due too sucking up too much trub, I could have got it to 5 but I really am not a fan of sucking up all that trub and letting it sit in my primary, maybe that's something I shouldn't worry about? Or should I make adjustments to get a little more wort into the boil kettle next time?

Hopefully some of you are still following this thread, it's been extremely helpful so far! The all grain thing really isn't such a big deal after doing it, and it's almost as fast as doing an extract brew with steeping grains. I should have made the switch sooner.

 

[pudland]

Took another reading after I chilled my wort down to 76* which took about 17 mins with my immersion chiller (that thing works WAY better in the winter when my well water is super cold) I may be building something new for this in the near future. Reading was 1.032 which is the same as my pre boil gravity. That's normal, right??

So beer smith tells me my OG should have been 1.043, how is that possible?

I know you said you brewed before but i have to ask.. Did you correct for temperature when you took the reading? My hydrometer is calibrated for 60*F. Won't get to 1.043 but you'd be closer.

 

[joshesmusica]

yeah reading error is pretty much the only way your pre-boil gravity is the same as the post-boil. so, no that isn't normal. it should be quite a bit higher.

you're boiling off the water, but the sugar stays behind, so your gravity is now higher.

as far as the trub thing, get all your wort into the fermenter:
http://brulosophy.com/exbeeriments/

find the ones that talk about trub, and read those first. then i'm sure you'll want to just scroll through the rest at some point.

 

[mcfire12]

I know you said you brewed before but i have to ask.. Did you correct for temperature when you took the reading? My hydrometer is calibrated for 60*F. Won't get to 1.043 but you'd be closer.

Hmm, ya know... I did not adjust! My buddy was there up until I started the boil and we took the readings first on his refractometer and I took my last reading with my trusty hydrometer and never corrected for temp. When adjusted my gravity is up to 1.037 but that still gives me a 62% efficiency. I was really hoping to hit at least 72% even tho i'm not totally sure of what that all means at this point. But the adjustment made it slightly better. Totally forgot about doing that, thank you! Still seems to be some issues here though.

 

[Denny]

So beer smith tells me my OG should have been 1.043, how is that possible? How does it go up after the boil?

It goes up after boil becasue you boil off water, but not sugar, so the wort is more concentrated.

 

[doug293cz]

I ended up mashing my 8.28 pounds of grain with 4.5 gallons of water. Dumped them in my brand new igloo mash tun, water was 162.6 when I added the grain it brought it down to 153.5 so that went about perfect!

Let sit for an hour and took another temp reading... 147.3* that was disappointing after reading most people only lost a degree or 2 at the most. Wonder what the deal was there?

I vorlaufed, then drained the mlt, turned on the heat, then added 3.5 gallon at 168* stirred, let rest maybe a min or 2, then vorlaufed and drained again. Took another reading and it was 1.032, beer smith said it estimated it at 1.037, so I was pretty happy with that. I spent WAY too much time worrying about how that process worked! Hit my estimated pre boil volume and my estimated pre boil gravity almost dead on. But...

Did my 60 min boil and hop addition, business as usual since I have done maybe 6 extract brews. Took another reading after I chilled my wort down to 76* which took about 17 mins with my immersion chiller (that thing works WAY better in the winter when my well water is super cold) I may be building something new for this in the near future. Reading was 1.032 which is the same as my pre boil gravity. That's normal, right??

So beer smith tells me my OG should have been 1.043, how is that possible? How does it go up after the boil? plugged in my numbers to beer smith and it dropped my efficiency down to 53.6% i'm definitely confused on this.

Volume into my fermenter after I drained from my boil kettle was pretty close, but I may need to make some adjustments to my process with this set up, I ended up with 4.75 gallon before I stopped draining due too sucking up too much trub, I could have got it to 5 but I really am not a fan of sucking up all that trub and letting it sit in my primary, maybe that's something I shouldn't worry about? Or should I make adjustments to get a little more wort into the boil kettle next time?

Hopefully some of you are still following this thread, it's been extremely helpful so far! The all grain thing really isn't such a big deal after doing it, and it's almost as fast as doing an extract brew with steeping grains. I should have made the switch sooner.

What were your measured pre-boil and post-boil volumes, and at what temperature were they measured? These can be used to double check what BS is telling you.

Brew on

 

[mcfire12]

Measured pre boil was just under 7 gallons, and I squeezed about 4.8 gallon into my fermenter. Left maybe a half or so gallon in the BK due to sucking up trub with my auto siphon. Which needs to be replaced with some kind of ball valve and pickup tube I guess. Not sure exactly what to get for that.

 

[joshesmusica]

What were your measured pre-boil and post-boil volumes, and at what temperature were they measured? These can be used to double check what BS is telling you.

Brew on

he answered those questions in the post the you quoted

edit: and then he beat me to it and answered again.

 

[doug293cz]

he answered those questions in the post the you quoted

edit: and then he beat me to it and answered again.

Can you highlight for me where it was in the post I quoted? I've reread it multiple times, and all I find are strike water volume, sparge water volume, and volume to fermenter. Didn't see pre-boil volume anywhere.

Brew on

 

[doug293cz]

Measured pre boil was just under 7 gallons, and I squeezed about 4.8 gallon into my fermenter. Left maybe a half or so gallon in the BK due to sucking up trub with my auto siphon. Which needs to be replaced with some kind of ball valve and pickup tube I guess. Not sure exactly what to get for that.

Assuming an average grain potential of 36 pts/lb (dry basis), 4% moisture, and 8.28 lbs of grain, your potential gravity points are:

36 pts/lb * 0.96 * 8.28 lb = 286.2 pts {0.96 is moisture adjustment}​

You recovered 7 gal (at assumed temp 170˚F) with SG of 1.032 => 32 pts/gal, so your total gravity pts in the BK are:

7 gal * 0.976 * 32 pts/gal = 218.2 pts {0.976 is volume shrinkage adjustment to RT}​

This results in a mash efficiency of:

218.2 pts / 286.2 pts = 0.764 => 76.4%​

I simulated your lauter efficiency at 91.4% so that puts your conversion efficiency at:

0.764 / 0.914 = 0.836 => 83.6%​

Assuming your post-boil volume was 5.25 gal, then your post-boil SG should have been:

218.2 pts / 5.25 gal = 41.6 pts/gal => 1.0416 SG​

With 4.8 gal to the fermenter at 1.0416 OG (41.6 pts/gal) you got:

4.8 gal * 41.6 pts/gal = 199.7 pts​

into your fermenter. This puts your brewhouse efficiency at:

199.7 pts / 286.2 pts = 0.698 => 69.8%​

This is significantly better than what BS calculated (53.6%), so I suspect you did not input all of your measured SG and measured volume data into BS correctly.

Brew on

 

[mcfire12]

Assuming an average grain potential of 36 pts/lb (dry basis), 4% moisture, and 8.28 lbs of grain, your potential gravity points are:

36 pts/lb * 0.96 * 8.28 lb = 286.2 pts {0.96 is moisture adjustment}​

You recovered 7 gal (at assumed temp 170˚F) with SG of 1.032 => 32 pts/gal, so your total gravity pts in the BK are:

7 gal * 0.976 * 32 pts/gal = 218.2 pts {0.976 is volume shrinkage adjustment to RT}​

This results in a mash efficiency of:

218.2 pts / 286.2 pts = 0.764 => 76.4%​

I simulated your lauter efficiency at 91.4% so that puts your conversion efficiency at:

0.764 / 0.914 = 0.836 => 83.6%​

Assuming your post-boil volume was 5.25 gal, then your post-boil SG should have been:

218.2 pts / 5.25 gal = 41.6 pts/gal => 1.0416 SG​

With 4.8 gal to the fermenter at 1.0416 OG (41.6 pts/gal) you got:

4.8 gal * 41.6 pts/gal = 199.7 pts​

into your fermenter. This puts your brewhouse efficiency at:

199.7 pts / 286.2 pts = 0.698 => 69.8%​

This is significantly better than what BS calculated (53.6%), so I suspect you did not input all of your measured SG and measured volume data into BS correctly.

Brew on

Wow, thanks for taking the time!! I'm uncertain where I could have missed entering anything into beer smith. As i'm looking at it right now, I input my measured pre boil volume at 6.8, my measured pre boil gravity at 1.032 which was taken from an auto temp refractometer, then my measured batch size 4.8 (into fermenter section) measured OG which is 1.036 with the temp correction taken with my hydrometer. It puts my brewhouse efficiency at 57.9%

What else am I needing to enter here?

In the Mash tab I have the measured pre boil volume at 6.8 gallon and gravity at 1.032 and it puts my mash efficiency at 72.9%

Not sure if i'm missing anything here or if I simply just messed up somewhere along the way. It seems like I got a good amount of the sugars out of the grains but everything seemed to take a turn after I boiled. Not sure what to think here!

 

[joshesmusica]

Can you highlight for me where it was in the post I quoted? I've reread it multiple times, and all I find are strike water volume, sparge water volume, and volume to fermenter. Didn't see pre-boil volume anywhere.

Brew on

yeah he didn't say it specifically. he just said that he hit the estimated volume. which i thought you were getting at that he didn't take volume measurements. i didn't realize you were going to do all that math for him. good work.

 

[joshesmusica]

Wow, thanks for taking the time!! I'm uncertain where I could have missed entering anything into beer smith. As i'm looking at it right now, I input my measured pre boil volume at 6.8, my measured pre boil gravity at 1.032 which was taken from an auto temp refractometer, then my measured batch size 4.8 (into fermenter section) measured OG which is 1.036 with the temp correction taken with my hydrometer. It puts my brewhouse efficiency at 57.9%

What else am I needing to enter here?

In the Mash tab I have the measured pre boil volume at 6.8 gallon and gravity at 1.032 and it puts my mash efficiency at 72.9%

Not sure if i'm missing anything here or if I simply just messed up somewhere along the way. It seems like I got a good amount of the sugars out of the grains but everything seemed to take a turn after I boiled. Not sure what to think here!

it's because as a few of us said, your method of measuring the wort post-boil must have been off. so he did the math for you to figure out what your post-boil SG should've been according to all of the numbers pre-boil, and what you boiled off. so your actual post-boil should've read somewhere near that 1.041 that he came up with.

 

[doug293cz]

Wow, thanks for taking the time!! I'm uncertain where I could have missed entering anything into beer smith. As i'm looking at it right now, I input my measured pre boil volume at 6.8, my measured pre boil gravity at 1.032 which was taken from an auto temp refractometer, then my measured batch size 4.8 (into fermenter section) measured OG which is 1.036 with the temp correction taken with my hydrometer. It puts my brewhouse efficiency at 57.9%

What else am I needing to enter here?

In the Mash tab I have the measured pre boil volume at 6.8 gallon and gravity at 1.032 and it puts my mash efficiency at 72.9%

Not sure if i'm missing anything here or if I simply just messed up somewhere along the way. It seems like I got a good amount of the sugars out of the grains but everything seemed to take a turn after I boiled. Not sure what to think here!

If I use 6.8 gal rather than 7.0 gal pre-boil, and assume a volume measurement temp of 212˚, then I get the same mash efficiency as BS. So, you can see how having complete and accurate measurement information can affect things.

I think the error is likely in your post-boil gravity measurement. In order for your post-boil gravity to be only 1.036, your post-boil volume would have had to be:

6.8 gal * 0.96 * 32 pts/gal / 36 pts/gal = 5.8 gal​

So, with 4.8 gal in the fermenter, you would have had to have had 1 gal worth of wort & trub left in the BK when you were done.

Brew on

 

[mcfire12]

I'm still confused. Here is a picture of my post boil gravity, this was taken while my boil kettle was draining to my fermenter bucket, maybe midway thru draining.

In beer smith under fermentation and inter fermenter, am I supposed to put 5.8 gallons into my measured batch size then? Since really post boil that's what I had. Even tho it says that number is supposed to be the actual volume into the fermenter?

 

[doug293cz]

I'm still confused. Here is a picture of my post boil gravity, this was taken while my boil kettle was draining to my fermenter bucket, maybe midway thru draining.

In beer smith under fermentation and inter fermenter, am I supposed to put 5.8 gallons into my measured batch size then? Since really post boil that's what I had. Even tho it says that number is supposed to be the actual volume into the fermenter?

Did you post the correct pic? That looks like 1.032 to me.

No, you should enter your actual volume into the fermenter for measured batch size, just as you did. If you really left a gallon in the BK, that explains your low brewhouse efficiency. That's really too much to be leaving behind.

Brew on

 

[mcfire12]

Definitely the right picture. It's almost as I lost no water from boiling for 60 mins, but that can't be... And I guess i'm not positive what I left behind, it could have probably been as much as a gallon tho I suppose. Well, with the trub it was probably a gallon, there wasn't too terrible much liquid left before I cut it off. Maybe 1/3 of a gallon of liquid at most.

 

[wilserbrewer]

Yep, unless your volume measurements are very accurate, your efficiency numbers are really only a guess. A quart or two isn't much, BUT it is 5-10% of the batch, that's huge.