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BIAB Mash profile

RickS

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In the mash profile for BIAB, do you set the "Tun Temperature" to the temp of the hot water that is in the tun or do you leave it as the temp of the grain?
 
It's weird that it has you add water at a certain temperature when your obviously boiling the water in the same pot that is your mash tun. Good question.
 
Neither.  It is the actual temperature of your mash tun before you add hot water or grain.

However, it depends on if you add strike water first and then the grain bag or put the grain bag in first and then add the strike water first.  I don't do boil it a bag, but if I did, I would do it this way (similar to how I hit my mash in temp with a standard all grain, but not BIAB method).

>  Set your mash tun temperature to be exactly what your strike temperature is calculated to be.
>  Set your grain temperature for the actual grain temperature.
>  Add your strike water to your mash tun at hotter than your strike temperature and stir, waiting for it to drop to your strike
          temperature. 
              (you'll now have a mash tun that is at your strike temperature and strike water that is dead on, which matches
                  your BS constants)

>  Add your grain bag to your mash tun and it should settle at exactly your mash in temperature.

If you were to use your actual cold measured mash tun temperature, then you have to have your mash tun specific heat calculation dead on.  For example, if your mash tun is at 70F and you add your strike water, if your specific heat (specific heat = how much or little the mash tun absorbs heat from your strike water) is too low or too high for your particular mash tun, your strike water will cool off too much or too little and it will not settle at your desired strike temperature.  My method, overcomes this, because by adding my water hotter (about 6 to 7F) than my strike temperature and stirring for about 5 minutes (usually doesn't take longer than this), I don't care how much or little heat is taken out of the strike water by the mash tun.  It adds maybe 5 minutes to your brew day to do this stirring and waiting for the strike water to drop a little, but it guarantees that you hit your strike and mash in temperatures dead on each and every time.

I hope you found this helpful.

PS...Boil In A Bag is actually a misnomer, since the Bag isn't actually boiled.  You mash in the bag and at the end of the mash, you lift the bag up and let it hang above the mash tun or boil pot until it stops dripping (squeezing is usually acceptable, since the mesh it usually tight enough in the bag to keep most tannin producing stuff from getting through to your wort).  Once it's done dripping, the grain bag is put aside and you commence with your boil.  In my humble opinion, a much more accurate term for the procedure would be Mash In A Bag (MIAB).
 
grathan said:
It's weird that it has you add water at a certain temperature when your obviously boiling the water in the same pot that is your mash tun. Good question.

He's not necessarily mashing in his boil pot.  I did two quasi-BIAB's early on.  I got a huge bag and put it in my 48 quart mash tun cooler.  I added the strike water hotter than strike temperature, when it settled to strike temp, I added the grains.  I stirred, closed the lid and let it mash.  Once mash was completed, I open the drain plug and lautered.  However, since I didn't have a valve on my cooler yet, it drained really fast as I lautered. 

Now I know that BIAB isn't usually lautered, so it didn't matter much, but I wanted to lauter to exclude as much grain husks, dust, etc. from getting into my boil pot.  Thus, I added a valve in place of the drain that was on my cooler.  I realized that the grain bag was acting as my mash tun screen, so I pony'd up the extra and put a screen in.  I still have the huge bag, but only use it on rare occasions, such as making wines, etc.  It makes getting the fruit out of my wine easier (primary in a bucket fermenter).
 
Thanks, Scott, BIAB is BREW In A Bag, not Boil in a bag, But other than that I understand,  I was asking because when you set the Tun Temp to the Mash Temp it drops the mash temp lower.  I knew that you have to have your strike water hotter than the mas temp because the grain will cause the temp of the water to drop.  When you have the water at, say 169 F and the Grain is at say, 72 f the temp of the water should decrease to or approx to the mash temp.
 
I have a electric 15 gallon keggie with a recirculating pump. I set my temp controller (PID) to 152 and when I reach that temperature I add my grain bag, the drop is marginal and the controller brings it up to 152 in no time. Sparge water should not be in the BIAB equation.
 
Found this thread first when searching, so going to add comment to it.  I was looking for how to indicate that my mash tun was my boil pot, and after mashing in too high, and looking at the comments here, I figured out what seems to be the 'right' answer.

Uncheck the box that says adjust temp for equipment.  This comes out the same as copying the strike temp into the mash tun temp box, and is simpler.  And it makes sense, since when using the boil pot to mash in there should be no temp adjustment for equipment, just for the grain.
 
wzd said:
Found this thread first when searching, so going to add comment to it.  I was looking for how to indicate that my mash tun was my boil pot, and after mashing in too high, and looking at the comments here, I figured out what seems to be the 'right' answer.

Uncheck the box that says adjust temp for equipment.  This comes out the same as copying the strike temp into the mash tun temp box, and is simpler.  And it makes sense, since when using the boil pot to mash in there should be no temp adjustment for equipment, just for the grain.

I agree and am closer to my numbers when I un-select the adjust for equipment. Also it is important to measure the temp of your grain.
 
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