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Pre-boil Volume was over 1g higher than Beersmith anticipated.

Jukas

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I recently reviewed http://www.beersmith.com/forum/index.php/topic,5140.0.html and setup an equipment profile for my Blichmann 15g kettle and 10gal Igloo Mash tun.  I started with the defaults of 1.25g loss to trub & chiller, 1.5g boiloff and .80 gal lauter tun deadspace.  I ended up way high on preboil volume so I did a dry run on my mashtun and kettle and found my mashtun deadspace was more like .5g and my brewkettle left .2g when draining just water, so I set it to .25g allowing for extra to be lost to hoptrub (I use pellet not cone mostly).

Last week I did my second brew after making those adjustments of a blonde ale as shown below

Code:
BeerSmith 2 Recipe Printout - http://www.beersmith.com
Recipe: Centennial Blonde
Brewer: 
Asst Brewer: 
Style: Blonde Ale
TYPE: All Grain
Taste: (30.0) 

Recipe Specifications
--------------------------
Boil Size: 8.27 gal
Post Boil Volume: 7.02 gal
Batch Size (fermenter): 5.50 gal   
Bottling Volume: 5.00 gal
Estimated OG: 1.043 SG
Estimated Color: 3.6 SRM
Estimated IBU: 20.3 IBUs
Brewhouse Efficiency: 67.00 %
Est Mash Efficiency: 82.2 %
Boil Time: 60 Minutes

Ingredients:
------------
Amt                   Name                                     Type          #        %/IBU         
8 lbs                 Pale Malt (2 Row) US (2.0 SRM)           Grain         1        82.1 %        
12.0 oz               Cara-Pils/Dextrine (2.0 SRM)             Grain         2        7.7 %         
8.0 oz                Caramel/Crystal Malt - 10L (10.0 SRM)    Grain         3        5.1 %         
8.0 oz                Vienna Malt (3.5 SRM)                    Grain         4        5.1 %         
0.25 oz               Centennial [10.50 %] - Boil 55.0 min     Hop           5        8.2 IBUs      
0.25 oz               Centennial [10.50 %] - Boil 35.0 min     Hop           6        7.0 IBUs      
0.39 oz               Cascade [5.00 %] - Boil 20.0 min         Hop           7        3.8 IBUs      
0.39 oz               Cascade [5.00 %] - Boil 5.0 min          Hop           8        1.2 IBUs      
1.0 pkg               Nottingham (Danstar #-) [23.66 ml]       Yeast         9        -             


Mash Schedule: Single Infusion, Light Body, Batch Sparge
Total Grain Weight: 9 lbs 12.0 oz
----------------------------
Name              Description                             Step Temperat Step Time     
Mash In           Add 14.19 qt of water at 159.8 F        150.0 F       60 min        

Sparge: Batch sparge with 2 steps (2.01gal, 4.38gal) of 168.0 F water
Notes:
------
OG Shoot for 1.039 - 1.042
Keep Mash temp between 148 - 151
Keep IBU's between 17-20

Created with BeerSmith 2 - http://www.beersmith.com
-------------------------------------------------------------------------------------

I used the exact water measurements for my mash in, mash out and sparge volumes and when I had finished collecting first and second runnings I had 9.25 gal in the brew kettle.  10gal of water for a 9.75lb grain bill seemed way to high for me, but I figured I'd trust Beersmiths output.

My 60 min boil only boiled off 1.25g instead of the 1.5 I thought I'd have, but I still ended up with over 7 gallons of wort going into my fermenters when I expected less than 6.

Do I have something setup improperly in my equipment profile, recipe or mash profile (I left it untouched at default settings)?
 

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There are a lot of places that this could be coming from.  .5g of dead space seems high for an igloo cooler.  I think that mine is more like about .25ish.  I would also suggest looking at your grain absorption setting.  It would appear that the program thinks that the grain is absorbing more than it really is or that the deadspace in the mash ton is wrong, or a combination of both.  The other thing I see is that your boil off rate seems high.  Rule of thumb is that you loose a gallon an hour for a nice rolling boil.  Remember that this will change with your elevation and how hard or soft you boil.  So, if you got extra water from the mash and didn't boil off like the program thought, that would account for the extra volume.  Just some random thoughts.

Cheers!
 
glienhard said:
There are a lot of places that this could be coming from.  .5g of dead space seems high for an igloo cooler.  I think that mine is more like about .25ish.  I would also suggest looking at your grain absorption setting.  It would appear that the program thinks that the grain is absorbing more than it really is or that the deadspace in the mash ton is wrong, or a combination of both.  The other thing I see is that your boil off rate seems high.  Rule of thumb is that you loose a gallon an hour for a nice rolling boil.  Remember that this will change with your elevation and how hard or soft you boil.  So, if you got extra water from the mash and didn't boil off like the program thought, that would account for the extra volume.  Just some random thoughts.

Cheers!

It's possible that .5g is wrong, however I did a "dry run" where I poured three gallons into the mash tun and then drained it until the value was sucking air and barely any water was coming out.  I poured the remainder of the water from the mash tun through a funnel into a 1 gallon jar.  It was approximately half full.

As for the grain absorption, it's currently set to  1.17gal but I cannot find anywhere in the mash profile or equipment profile to change that.  Either I'm looking in the wrong spot, or it's a static non editable field.

As for boil off, my understanding was that it could change due to altitude and surface space of the BK.  I use a Blichmann 15gal kettle which is 16" in diameter.  According to http://sigginet.info/brewing/tools/boil-off-calculator/ a 60 minute boil & 16" diameter boils off 1.47 US Gallons in an hour.  I found mine boiled off more like 1.25.
 

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When you did the mash tun test, did you drain through a hose that would cause a siphon?  Mine leaves half a gallon when there is no hose because the siphon breaks at the level of the output valve.  With a short hose in place, it will siphon down to about 1 cup left.

I've been struggling with getting my volumes to match up.  I keep getting 'watered down' beers with low starting OG.  I think my boil off and trub losses are set too high in beersmith.  I'm getting correct pre-boil volumes, but with low gravity and then too much post boil volume...

good luck!
 
Grain absorption is on the advanced tab. 

Traditionally, deadspace is the volume below a false bottom and below the pickup.  Its the area of pure wort, not wort+grain.  When you do a water only test, you will over-estimate the undrained wort from a real mash, by AT LEAST 2x.  Your test is measuring the volume below the pickup, but in a real mash that volume is filled by grain and wort.  So, the question is how much of that 1/2 gallon of space is filled by wort?

You could do a small test and put 1/2 gallon of grain in a container and then see how much water it took to JUST COVER the grain.  My guess is a couple of cups.  To further complicate matters though, at the end of the sparge the bottom of the grain bed will have been significantly compacted by the weight of the grain bed above and the filtering action itself.  So, this test is still likely to over estimate the amount of unclaimed wort. 

My guess is that you have more errors in your basic volume measurements just because of the way most of us measure things.  If you don't have a false bottom, as described above, I'd set the deadspace to zero.  Its just not enough volume to throw any of the other calculations off.

Regarding boiloff rate: kettle geometry plays a role...but, in the normal geometry ranges of available kettles (no one boils in a skillet....or a 1" diameter copper tube) its mostly a function of the heat flux into the kettle.  Every amount of heat that goes into the wort must result in a certain volume of water vapor being produced.  In other words, your burner setting has more impact that the shape of your kettle. 

From a practical standpoint what that means, is that you have to measure and control your boiloff.  I calculate my boiloff at 15 minute intervals throughout the boil, and adjust my flame based on the result. 

Boiloff rate should be considered a recipe parameter, as it has a definite flavor impact.  Below 9% per hour is not vigorous enough and will leave DMS in the wort.  Above 15% per hour will impart melanoidin flavors.  The higher the rate the more melanoidin.  Higher rates will also darken the beer. 

I usually target about 12% boiloff (1 gallon per hour for an 8 gallon pre-boil).  That gives me leeway to adjust up or down without getting out of the 9% - 15% range if I'm too low or too high at my measuring points.  So, at 15 minutes I should be down by 1 quart.  If not I can turn the flame up or down a bit to change the boil-off without exceeding the 9-15% range. 

Remember, that in order to do this you have to be able to precisely/and accurately measure your kettle volume to a quart or better.  I have a site glass on my keggle, calibrated using measured water additions. 
 
I'm wondering how to successfully account for dead space with my brew pot. I have roughly 2 gallons below the false bottom, but only 1 gallon of that is below the valve and lost. It seems to me that if I calculate lauter tun deadspace at that which I will actually lose (1 gallon), won't that throw off my grain to water ratio? How does Beersmith factor in the gallon of wort between the grain bed/false bottom and my true dead space?
 
Jukas said:
I ended up way high on preboil volume ..............


One option is to close the valve when you hit your targeted pre-boil volume.  There's so many variables to be dialed in at first, you have to pick your battles. 

I wasted a lot of time trying to figure out where all the water was going (didn't go) and finally decided to nail the pre-boil volume.  I had a stick and could measure that one.

Then I started backing into how much excess water I was putting into the MLT, so I put less in the HLT, etc.  The other tips on verifying losses and dead space are valid, but closing the valve is pretty easy.  With a known volume, and known SG, you have a fixed concentration of sugars and can fiddle with your boil rate to hit your desired FG, and adjust the water on the next batch.  Just another approach.  Gradually you'll find the right numbers and be nailing it.  Bon chance. 
 
captgus said:
I'm wondering how to successfully account for dead space with my brew pot. I have roughly 2 gallons below the false bottom, but only 1 gallon of that is below the valve and lost. It seems to me that if I calculate lauter tun deadspace at that which I will actually lose (1 gallon), won't that throw off my grain to water ratio? How does Beersmith factor in the gallon of wort between the grain bed/false bottom and my true dead space?

Your situation is one that cannot be handled by beersmith. It does not allow for a difference betwen the false bottom and tthe spigot.  You are going to have to trade off accurate predictio of strike temp erature and preboil volume/gravity. 

I would recommend prioritizing for preboil volume and gravity, by setting your dead space to the volume below the spigot(1 gallon).  Then I would up your mash thickness to greater than 1.5 gal/lb. That should keep your thickness in a decent range. 
 
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