What is the proper way to handle reaching the pre-boil wort volume before your mash t

hello everyone,

I have brewed four batches of all grain so far and they have all turned out pretty decent. I am still getting all the nuisances and system specific issues down now.

The only thing I have had trouble finding information on is boil volume issues.

What is the proper way to handle reaching the pre-boil wort volume before your mash tun is done with the second runnings?

Stop it at the proper level and the rest is waste? All that was taken into consideration with the calculations though so IMO, it would throw the gravity off.

Fully drain mash tun second runnings and boil longer? But how do u compensate for the hop schedule if you originally wanted to do a 60 min boil.

One last thing...if you are doing a 5 gal batch, do you stop the boil at 5 gal, or do you stop it with your wort shrinkage of 4% added to the 5 gallons?

Any other input or tips?
Thank you.

I think its hard to do the all the calculations on the piece of paper so i would recommend getting beersmith. For $20 you will be able to get all the numbers of lbs, gal and qt you need to add to get the final volume of wort without wasting anything. It may take one or two brew sessions to get required numbers for your equipment (dead space in MT and BK, boil off rate ect) but after that its easy and very useful.

The easiest way to get your pre boil volume is to collect your first runnings. Measure that volume. Subtract that from your pre boil total. That is how much sparge water you will need to add to reach pre boil volume. After the first runnings your grains have already absorbed what they're going to so any additional water that goes in should come back out in second runnings.

Edit:
I shoot for 6.5pre boil to wind up with just over 5gallons post boil so I get a full 5gallons into the keg.

GilSwillBasementBrews said:

The easiest way to get your pre boil volume is to collect your first runnings. Measure that volume. Subtract that from your pre boil total. That is how much sparge water you will need to add to reach pre boil volume. After the first runnings your grains have already absorbed what they're going to so any additional water that goes in should come back out in second runnings.

Edit:
I shoot for 6.5pre boil to wind up with just over 5gallons post boil so I get a full 5gallons into the keg.

Click to expand...

Assuming your batch sparging, this info is gold. Even on my RIMS set up, I do some simple math on a piece of scrap paper to figure out my sparge volumes. Perfect everytime. Just subtact your first runnings from you pre-boil total, divide by two, and you have your two sparge volumes.

As you are mentioning the 4% wort shrinkage, I assume you are using brewing software of some sort.
During the brewing session, you will lose volume for several different reasons:

• Grain Absorption. (The brewing software should handle this)
• Dead space, and wort trapped in equipment. (This should be constant)
• Trub (and hop absorption if you use whole hops). (This will vary according to the grain bill and amount of hops)
• Evaporation (This will vary slightly depending on the weather, and boil vigorosity. I know there is no such word, but you understand it). It will also depend on the boil time, but the software should take that into account.

Carefully measuring each of these items should enable you to check your brewing software setup, which in turn should get you in the ball park.
Then do what GilSwillBasementBrews recommended to accurately adjust the volume for each brew. (I don't do this because I fly sparge. I sparge until I reach the required volume or until the gravity of my runnings drops below 1.010, then I make up any required volume with water.)



You should try to end up with at least the batch size + 4% at the end of the boil. I also need some extra for trub and hop absorption. Actually, I know I need 7g pre-boil with 2 oz hops, and an extra 12 oz for each extra once of hops, and I end up with between 5.00 and 5.25 gallons in the fermenter.


-a.

Depends on the system....
You need to calculate mash tun loss first.

then I would say each batch should get you closer to figuring out your losses... personally I have ½ gal loss in my mash tun, so whatever I calculate total water to be I need to add ½g. Then my boil off. this can be tricky because most software calculates evaporation as a % of the volume... this of coarse is not correct. Evaporation is constant and not based on the volume, but on the time boiling. Once you figure your boil off based on a steady boil it should be a constant (example:5 Qt/hour).

After all is said and done I would say stop collection once you reach your boil volume (take a gravity reading), and chuck the rest. At this point you are adding very little fermentables per fluid oz and suffer the real possibility of under shooting your gravity with that diluted wort.

Thank you all very much.