Happy HolidaySs Giveaway - Winners Re-Re-Re-Re-Drawn - 24 hours to Claim!

Get your HBT Growlers, Shirts and Membership before the Rush!

 Home Brew Forums > 2qt./LB Mash...
02-24-2009, 01:24 AM   #101
Kaiser
Feedback Score: 0 reviews

Recipes

Join Date: Nov 2005
Location: Pepperell, MA
Posts: 3,904
Liked 115 Times on 71 Posts
Likes Given: 4

Quote:
 Originally Posted by cactusgarrett Okay, here are the specifics: 12.5lb pilner malt 0.5lb cara-pils 1.75qt/lb (22.75qt strike) 153F sacc rest for 60min 2 sparges of 2.5gal each (to reach 170F) 1st runnings = 1.060 2nd runnings = 1.037 3rd runnings = 1.022 pre-boil = 1.045 (1.053 target for 70%) 7gal boil, 5.5gal final vol (90min boil) Let me know if you're interested in any other details. garrett
Your 100% conversion first wort gravity would have been around 1.073. You got only 1.060. This makes for a conversion efficiency of 60/73 = 82% which is a bit low. 18% of the starch didn't convert in the mash.

But your pre-boil numbers don't make sense. 7 gal @ 1.045 is 7*45 / (12.5 *36 pppg) = 70%. But you say that you got only 66%.

70% eff. into kettle and 82% conversion efficiency means that your lauter efficiency was about 85%. This is what I would expect from batch sparging 12 lb of grain twice.

So your problem is that your thin mash doesn't convert as well as your thick mash. I have been claiming that the opposite should be true. Odd how this didn't work for you. Was the recipe the same as the recipes that you mashed thick?

Kai

02-24-2009, 02:36 AM   #102
JVD_X
Feedback Score: 4 reviews

Recipes

Join Date: Jan 2008
Location: Gainesville, Virginia
Posts: 1,492
Liked 3 Times on 3 Posts

Quote:
 Originally Posted by Kaiser Your 100% conversion first wort gravity would have been around 1.073.
Kai - how is that calculated?
__________________

- JVD_X

02-24-2009, 02:51 AM   #103
Kaiser
Feedback Score: 0 reviews

Recipes

Join Date: Nov 2005
Location: Pepperell, MA
Posts: 3,904
Liked 115 Times on 71 Posts
Likes Given: 4

Quote:
 Originally Posted by JVD_X Kai - how is that calculated?
You'll have to use the plato scale, which is basically the weight % of the extract in the wort. And it works best when working with metric:

13 lb = 5.85 kg malt which has ~80% extract: 4.68 kg

He is using 22.75 qt = 21.5 l = 21.5 kg water

If all that extract is dissolved in all that water the wort strength in Plato will be:

100% * 4.68 / (4.68 + 21.5) = 21.1 %Plato

or 1.084 SG

Ooops, this doesn't really match up with my table and with what I said before. Let me run the numbers again and see if I have a bug in my table.

Kai

02-24-2009, 03:05 AM   #104
JVD_X
Feedback Score: 4 reviews

Recipes

Join Date: Jan 2008
Location: Gainesville, Virginia
Posts: 1,492
Liked 3 Times on 3 Posts

Quote:
 Originally Posted by Kaiser You'll have to use the plato scale, which is basically the weight % of the extract in the wort. And it works best when working with metric: 13 lb = 5.85 kg malt which has ~80% extract: 4.68 kg He is using 22.75 qt = 21.5 l = 21.5 kg water If all that extract is dissolved in all that water the wort strength in Plato will be: 100% * 4.68 / (4.68 + 21.5) = 21.1 %Plato or 1.084 SG Ooops, this doesn't really match up with my table and with what I said before. Let me run the numbers again and see if I have a bug in my table. Kai
Yep - I got 1.082 in beersmith with 100% conversion.
__________________

- JVD_X

02-24-2009, 03:25 AM   #105
Kaiser
Feedback Score: 0 reviews

Recipes

Join Date: Nov 2005
Location: Pepperell, MA
Posts: 3,904
Liked 115 Times on 71 Posts
Likes Given: 4

Let's try again:

13 lb = 5.90 kg; at 80% extract potential this is 4.72 kg of extract

22.75 qt = 21.53 l = 21.53 kg water

So the weight percentage of the extract dissolved in that water is:

100% * 4.72 / (4.72 + 21.53) = 18.0 %Plato

This is 1.074 SG

My table is correct. JVD_X, if you do this with Beersmith you cannot use 22.75 qt as the resulting volume since the dissolved extract actually expands the volume of the water. That's why this calculation cannot be done as easily with the pppg based method. The expansion is about 0.075 gal/lb of dissolved extract. In this case 0.78 gal. This brings the total wort volume on the mash tun to 6.46 gal. With 36 pppg and 13 lb I get a gravity potential of 72 points.

No change necessary to my other posts.

Kai

__________________
BrauKaiser.com - brewing science blog - Twitter - water and mash chemistry calculator

02-24-2009, 03:43 AM   #106
JVD_X
Feedback Score: 4 reviews

Recipes

Join Date: Jan 2008
Location: Gainesville, Virginia
Posts: 1,492
Liked 3 Times on 3 Posts

Quote:
 Originally Posted by Kaiser Let's try again: 13 lb = 5.90 kg; at 80% extract potential this is 4.72 kg of extract 22.75 qt = 21.53 l = 21.53 kg water So the weight percentage of the extract dissolved in that water is: 100% * 4.72 / (4.72 + 21.53) = 18.0 %Plato This is 1.074 SG My table is correct. JVD_X, if you do this with Beersmith you cannot use 22.75 qt as the resulting volume since the dissolved extract actually expands the volume of the water. That's why this calculation cannot be done as easily with the pppg based method. No change necessary to my other posts. Kai
But - the grain absorbs about 1.9 gallons of water or so (@ 0.15 gallons per pound) that reduces your water to 14.33 kilograms.

so 100% * 4.72 / (4.72 + 14.33) or 24.7 plato or 1.105

Again - I probably don't understand the science.
__________________

- JVD_X

02-24-2009, 03:49 AM   #107
Kaiser
Feedback Score: 0 reviews

Recipes

Join Date: Nov 2005
Location: Pepperell, MA
Posts: 3,904
Liked 115 Times on 71 Posts
Likes Given: 4

Quote:
 Originally Posted by JVD_X But - the grain absorbs about 1.9 gallons of water or so (@ 0.15 gallons per pound) that reduces your water to 14.33 kilograms. so 100% * 4.72 / (4.72 + 14.33) or 24.7 plato or 1.105 Again - I probably don't understand the science.
The "water" absorbed by the grain is actually wort and has the same gravity as the rest. Maybe some water that actually penetrates into the husks is just water, but that doesn't amount to 0.15 gal/lb.

Kai
__________________
BrauKaiser.com - brewing science blog - Twitter - water and mash chemistry calculator

02-24-2009, 01:00 PM   #108
cactusgarrett
Feedback Score: 0 reviews
Recipes

Join Date: Apr 2008
Posts: 984
Liked 7 Times on 5 Posts
Likes Given: 8

Quote:
 Originally Posted by Kaiser But your pre-boil numbers don't make sense. 7 gal @ 1.045 is 7*45 / (12.5 *36 pppg) = 70%. But you say that you got only 66%.
I was just going by what Beersmith gave me for my Efficicency into Boiler based on the numbers i plugged in. I didn't hand calc anything.

Quote:
 Originally Posted by Kaiser ...about 85%. This is what I would expect from batch sparging 12 lb of grain twice... So your problem is that your thin mash doesn't convert as well as your thick mash.
What do you recommend i do in the future, then, if bumping to 1.75qt/lb didn't show an increase (taking into account loss of sparge efficicency)?
__________________

~~ Malted barley wants to become beer. ~~

02-24-2009, 03:15 PM   #109
Kaiser
Feedback Score: 0 reviews

Recipes

Join Date: Nov 2005
Location: Pepperell, MA
Posts: 3,904
Liked 115 Times on 71 Posts
Likes Given: 4

Quote:
 Originally Posted by cactusgarrett I was just going by what Beersmith gave me for my Efficicency into Boiler based on the numbers i plugged in. I didn't hand calc anything.
Quote:
 Originally Posted by cactusgarrett

Beersmith is right and I was wrong. I forgot to compensate for the expansion of the wort at boiling temps. It is 4% lager than at room temp and thus the efficiency appears 4% higher. 66% is correct and I also get this when I multiply the 7 gal with 0.96.

Quote:
 What do you recommend i do in the future, then, if bumping to 1.75qt/lb didn't show an increase (taking into account loss of sparge efficicency)?

This brings us back to looking at the parameters in the mash and the most promising would be a finer crush, given that your pH is in an acceptable range. Do you have control over the crush?

Aside from that, do you check for iodine negative wort at the end of the mash? How long do you mash for and at what temp?

Kai
__________________
BrauKaiser.com - brewing science blog - Twitter - water and mash chemistry calculator

02-24-2009, 03:51 PM   #110
slimer
Feedback Score: 0 reviews

Recipes

Join Date: Oct 2007
Location: Westmont, IL
Posts: 723

So Kai, I was trying to figure this out yesterday. If you have the Lintner of the malts in a mash, is there a formula that you can plug in to know how long you need to convert the starches?

This is the example I was trying to figure out. They are presented in percentage of the mash and degrees Lintner
40% of (Wheat Malt @ 74 deg Lint)
30% of (Vienna Malt @ 50 deg Lint)
20% of (15% Flaked Wheat & 5% Honey Malt @ 0 deg Lint)
10% Honey (Not in Mash)

My main fear is that if I do a 122 deg Protein Rest for 20 Mins and a 60 Min Sacc Rest at 150, the Vienna and the Wheat malts do not have enough diastic power to convert the Flaked Wheat and the Honey Malts.

This is at 1.5 qt/lb, but with my new system, I would probably be increasing the ratio.

I found this formula, but I don't know how it/if applies.

__________________