Batch sparging and adding water before boil.

[america]

I've been batch sparging since I started doing AG (about 4-5 months ago), mashing in a 10gal round cooler and using a 20 gal kettle for my brew kettle and HLT. I've been trying to dial in my system using BrewTarget, but I can never seem to hit the correct preboil gravity, its always really high. Ive been compensating for this high gravity reading by adding 1/2 gal - a full gal of water before the boil (as my boil off rate is ~2 gal an hour because my kettle is so wide). My question is, should I just be sparging more? Or is adding this much water before the boil ok? The beers have tasted fine in the end, but it just doesn't seem like im doing it right.

Not sure if it helps or not, but for reference I brewed THIS recipe last night, mashed in with 3.8 gal (1.3qt per pound, and hit 154 on the nose), and batch sparged with 6.5 gal. First runnings were about 1.5 gal @ 1.090 and second runnings were ~5 gal @ 1.030. This got me to a gravity of 1.047 before the boil.
EDIT:After adding the extra 3/4 gal of water the preboil gravity was 1.042 or so, and that got me to 1.054 after the boil.

Any help with this would be great.

 

[david_42]

I'd increase the sparge water. What you are doing isn't wrong, but as long as you need the extra volume more sparging makes sense.

 

[Sherpa FE]

I may be missing something in your post, but didn't you say your pre-boil gravity is always high, and that's why you are adding water? To dilute it back down to the proper pre-boil gravity?

If that's the case, I would think that finding the cause of always having a high pre-boil gravity, would be more appropriate instead of "fixing" it by diluting the wort with water.

Are you consistently hitting your desired volumes?

To answer your original question, adding anything pre-boil never hurts. It is just better to find out where your particular system needs tweaking, so you don't have to.

 

[america]

Sorry, I have been getting high pre-boil gravity just about every time, but I guess should measure my volumes a bit better. I just did the 'make some lines on my mixing spoon' method, but then found out that my stove top isnt actually level, so they are very rough estimates, which vary by about a half a gal from the front to the back of the kettle. I'll try to fix that ASAP and just start using more sparge water. Do you think I should do more than 1 batch sparge or just up the volume of water in that batch?

Thanks for the quick replies guys!

 

[Sherpa FE]

Opinions on batch sparging will vary, no sparge to batch sparge to double batch sparge, it's all on what works best for you, with the level of results that you think is worth your time.

I teach new brewers to do a double batch sparge, it's the same amount of water as a regular sparge, it's just split into 2 equal sparges. Some people get more fermentables out of it, some say it doesn't do anything, or the results are marginal and not worth the time.

Experimentation is the only way to know what works best for you and your system, extensive note taking when learning any new system is a must, and can save a lot of heartache down the line.

 

[BBL_Brewer]

The thing is, like Sherpa said, if you are hitting your volumes and still get a higher than expected pre boil gravity, then you are getting a better efficiency than what your software is accoutning for. This means that you should be using a little less grain. If your preboil volumes are comming up low, then yes, adding more water (ie sparging more) is the solution.

 

[america]

Thanks guys, I'll try sparging with more water first and then adjusting the efficiency on the software if that's needed after another run though.

 

[DSmith]

If your efficiency is too high, replace some of the wort with brewing water to meet the recipe pre-boil gravity. I often use this because planning for 5% lower efficiency than you expect is cheap and gives you options before your boil. Increasing your boil volume is ok if your pot can handle it and if you want to increase each hop quantity. I generally plan for the biggest pre-boil volume my equipment can handle and adding more water isn't a safe plan vs. following the equation below.

Equations for Efficiency Too High without Changing Pre-Boil Volume

(PBV) Pre-Boil Volume [Gallons]
(PBG) Recipe or Brewing Program Pre-Boil Gravity
(AG) Actual Mash Gravity
(RV) Removed Volume to be Replace with Brewing Water [Gallons]

RV = PBV – PBV*PBG/AG

Example

PBV = 4.125
PBG = 48
AG = 54
RV = 4.125-4.125*48/54 = 0.46 gallons (Remove this volume of wort and replace with this volume of brewing water)

 

[BBL_Brewer]

If your efficiency is too high, replace some of the wort with brewing water to meet the recipe pre-boil gravity. I often use this because planning for 5% lower efficiency than you expect is cheap and gives you options before your boil. Increasing your boil volume is ok if your pot can handle it and if you want to increase each hop quantity. I generally plan for the biggest pre-boil volume my equipment can handle and adding more water isn't a safe plan vs. following the equation below.

Equations for Efficiency Too High without Changing Pre-Boil Volume

(PBV) Pre-Boil Volume [Gallons]
(PBG) Recipe or Brewing Program Pre-Boil Gravity
(AG) Actual Mash Gravity
(RV) Removed Volume to be Replace with Brewing Water [Gallons]

RV = PBV – PBV*PBG/AG

Example

PBV = 4.125
PBG = 48
AG = 54
RV = 4.125-4.125*48/54 = 0.46 gallons (Remove this volume of wort and replace with this volume of brewing water)

Problem is, you won't maximize your efficieny that way. Sparging more and using less grain is the most logical approach. The whole point of using software (other than ease of calculations) is to dial in the process and get consitent results every time. I used to guess at it when I first started AG and would just adjust my sparge volume as needed to hit my pre boil volume. Now I use software and can rest assured that everything will go as planned without having to make adjustments on the fly.

 

[DSmith]

I don't see maximizing efficieny as a priority but would rather spend $2 more on grain to overshoot the gravity and correct back to the recipe pre-boil gravity with a quick calculation and swap out some wort for brewing water if needed. I can absolutely see if you're brewing the exact same beer over & over and have your own crusher that you can be more precise.

The sparge volume is constantly changing based on the OG of the beer. Getting the volume is simple as long as you measure your first runnings volume and sparge with the difference to get the pre-boil volume. Getting the pre-boil volume (knowing boil-off rate and boil time) is top priority and usually comes out a little high on pre-boil gravity which is fail proof to adjust. The extra wort gets frozen for yeast starters.