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No were near the expected gravity

KWMTrumpet

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Lately my all grain brewing OG numbers have been hitting a little low and recently I was off by a substantial amount on my last brew.  Now there are a couple of factors for this:

1. Back in February I started using an outside burner to do the boil(Camp Chef) and a 7 half gallon stainless steel pot.

2. I have been weighing and milling my own grain for almost two years now (Monster Miller MM3-2.0 with Harden Steal)

3. Now using BeerSmith2, use to use BeerToolsPro. After reading and watching the setup videos on the BeerSmith, I felt I was ready to use it. Added all my equipment as mentioned in the tutorials.

4. I started using a carbon filter to filter my water for the past year now.



Here is my numbers and grain for a Russian Imperial Stout (5.5 gallon batch) I brewed yesterday:

Est Pre-boil Vol. 6.82
My Pre-boli: 6.8
Pre-boil Gravity: 1.100
My Pre-boil gravity: 1.070 (and I cooled it down into the mid 70's to check reading)
Est Original Gravity 1.1210
My OG: 1.076
pH Mash right at 5.2
pH Sparge 6.0

10  lbs Maris Otter
4    lbs Pale Chocolate Malt
2.5 lbs Crystal 120
2    lbs Crystal 60
2    lbs Crystal 40
.5  lbs Roasted Barley
2    lbs Oats, Flaked

Set the program for: (Based off the options provided by BeerSmith2)

Single Infusion, Full Body, Batch Sparge
Set steep temperature at 156 degree F for 45 minutes. (I usually do 60 minutes, but trusted the program this time)
Batch Sparge at 168 degree F
Pre-Boil volume was 6.8 gallons

All I can think of for my issue is:

1. Do not have the right boil down calculations. Either too much or too little is being evaporated during the boil. If so, how would I figure out the correct boil off rate?

2. The mill is not grinding the grain up fine enough and might have to do two mills to get a finer crushed grain.

3. Not enough Marius otter.

4. Two much water is being added to the grain bed prior to steeping the mash.

5. My scale to weigh the grain is off.

Thank you for your time if you made it to this point in this post.

Kevin
 
I calculate that OG if:
Your preboil volume was 9.5 gallons  :eek:
You used 5lb Maris Otter  ???
You added a couple gallons of topoff water ;D
You mistook your thermometer for a hydrometer  :eek:
You forgot to mill  ;)


My guess is you weighed your grain wrong or your efficiency was totally screwed up.  Did you change sparging process or equipment recently?
 
I think you've just run into the limit of physics.  For an all wort brew like that your efficiency is going to be in the 50s or lower...unless you just sparge and boil down.  Sure there's 800+ potential points in the grain....but, you can't get it out without using too much water and having a lower pre-boil SG.  Then you have no choice but to boil it down. 

There's just no way to get that kind of a SG from a plain ol' mash.  The IDEAL gravity of first runnings of a 1.25 qt/lb mash is 1.096.  You can drop down to 1.15 qt/lb and get a higher first runnings SG.  But, you aren't going to get 7 gallons of first runnings that way.  Your second runnings will be much lower and the average will be well below 1.100. 

So, in order to make 7 gallons of an ALL-GRAIN 1.100 wort I think you would need something like 11 gallons of strike water and about 44 lbs of grain. 

Another way to do it ALL GRAIN would be to sparge out the right gravity points in a larger volume of water and do an extended boil. That probably won't be ideal from a flavor point of view...lots of kettle carmelization.

Finally, you could supplement with extract, sugar or both to get your target OG. 


 
I agree with tom.  You've got a ton of grain there, and as such you need to use a ton of water to wash off the sugars.
 
Yea, if you've not done many big OG brews, then I would guess your actual EE% was much lower than you put into BSmith. 

For a RIS, you can also try dark candi syrups for the dark fruit/vinous flavors as well as extra gravity points. 


"Single Infusion, Full Body, Batch Sparge"

I don't batch, but does this mean only one rinsing?  I'd think you'd do 2-3 (smaller) infusions on a big brew like this, then boil longer, then add DME/sugars/syrups to get to the goal. 
 
Thank you Tom, MaltLicker and everyone else. Today is my next brew day and will try what you guys suggested.  I have been doing high gravities for a couple of years, yet now that I am brewing outside with the propane burner, the gravities have changed. My attempts today will include finer milling of the grain and multiple sparge. Will let you know how it turns out.

Kevin
 
Batch sparge doesn't imply a specific number of rinsings.  2 or 10 is still "batch sparging".  From a theoretical point of view, there is almost no benefit to doing more than 3 batches---even three only gains about 2% efficiency over two (for the same preboil volume).

If I were doing an all grain RIS, I would mash as low as possible.  You are going to get a TON of malt character anyway...my primary concern would be trying to keep it from being too MUCH. An all malt 1.120 OG might finish at 1.030...that is a LOT of residual sweetness to contend with.  Even with a HIGHLY attenuative yeast (82%), you would still be looking at a 1.021 FG....best case.  I'd probably use a light or ultra-light body mash in the mid 140s. 

In order to avoid too much kettle carmelization from an extended boil, you might consider a two stage boil.  Set your first runnings aside because they are almost the right gravity already.  Then boil your second runnings until they get close to the right gravity.  Then add the first runnings back and start the final boil with hops. 

The degree of kettle carmelization is a function of the heat load and the wort gravity.  By boiling the 2nd runnings you keep the gravity lower, then turn the heat down so it boils as slowly as possible until you have boiled off enough water from the wort.  You just have to do the math.  Just figure your total needed boiloff and boiloff-rate and divide up as required. 

 
I have made several 9 and 10% beers with a  48QT cooler.  I simply add the grain and fill it to the brim with water.  Stir once and close tightly for an hour. 

My manifold is 4 copper .5" tubes running the length of the cooler interconnected at both ends. the pipes are evenly spaced from the outside edges.  Silicon hose connects the far end to the valve barb fitting.

I then vorlauf and drain the cooler at full flow with a .5" hose. 

I measure the volume in the kettle then add the appropriate amount of sparge water to reach my (usually) 8 gallon preboil volume.  I stir and seal for 15 minutes.  Then vorlauf again and drain.

My efficiency it 75% +/- a few points.  So, geometry and process seem to be factors as well as simple conversion and grist thickness.

/Joe
 
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