Batch sparge questions

[winvarin]

I am trying my first batch sparge this weekend. I am going off some of the assumptions made in Denny's article at http://hbd.org/cascade/dennybrew/.

My main assumption is his .1 gallon per pound absorption rate. Since I have never batch sparged, I gotta start somewhere.

Here's my grainbill -
4 lbs. - 2 row
1.5 lbs. - pilsner
3 lbs. - wheat malt
3.75 lbs. - rye
1 lb. - rice hulls (in mash)

I'm going for 1.3-ish quarts per pound of grain in my mash. Rough numbers only (since I have no brewing software) would put me at 4.5 gallons of strike water.

If I assume the .1 gallon/pound of absorption, that should leave my first running producing about 3.1 gallons of wort. With the grain already saturated, that would mean I am looking at another 3.9 gallons to produce 7 gallons in the brew kettle.

So a coupld of questions:
1. Do these numbers look right?
2. If I am looking to bring this volume of mash to about 168F for mashout, what should the temperature of the 3.9 gallons (I'm going to do 4 to be safe) sparge water?
3. I assume it is better to be safe than sorry. That being said, how much additional sparge water should I prepare?
3a. If I have to use the additional water in reserve, do I just do a 3rd running using the same method? (add water, stir mash, recirculate until clear and then drain quickly)?
4. I assumed 65% efficiency and came up with around a 1.050 starting gravity for this batch. Should I add any additional 2-row to account for loss of efficiency due to the batch sparging? I regularly get around 70% or better when fly sparging with this setup (10-gal round igloo cooler).
5. Are there any other tips? Is the "let it rip" sparge method what most of you batch spargers use?

 

[android]

1) I think those look about right, one option is to use a 5 gallon bucket with marks to measure how much you get out of the first runnings. Then you can calculate the exact grain absorption.

2) I normally try to get my sparge water to about 185, and divide how much is needed for the full volume into two batch sparges. that way, if the first 2 gallons (or however much you need) doesn't get me to 168, the second 2 gallons normally will. And quite frankly, i normally end up a little high or low from 168 and the end result doesn't seem affected.

3) I would add at least one gallon, if not two, just to make sure. I normally start with 11-12 gallons of water and normally have a few leftover to help with cleanup.
3a) Like i said before, i would sparge twice, this makes sure the sugars are as rinsed as you're going to get them.

4) I think you'll be surprised by the efficiency you will get with batch sparging. I own a barley crusher and that combined with batch sparging gets me 80% every time.

5) Do you mean open the valve and let it flow fast? If so, yes, I do do that. I start it slowly into a 2qt pitcher and once it's going a bit, I open the valve wide open, after the pitcher is filled, i let it go into the kettle or a graduated bucket (i like to be fairly precise), and i pour the pitcher back into the mash tun as it's draining. I'm not sure if you're familiar with this concept, it's called a vorlauf. You basically set up the grain bed and collect the grain material that is in the manifold and pour it back in when the runnings are clear (2qt is normally enough for that to happen).

Good luck, it's actually a robust and easy process, you will be pleased with the results.

 

[carl_g]

+ 1 on the double batch sparge method. Using this you don't need to mash out. It saves time and I regularly get 82% efficiency this way.

 

[JuanMoore]

+1 to the above comments.

1) The numbers look like a great starting point, but remember to take accurate measurements so that you can nail down the numbers for next time. If you already brew all grain, how do you not know your grain absorption rate?

2) I usually heat the sparge water to ~180F, but I also prefer missing the denaturing temps over extracting tannins, and I'm convinced that sparge temp has little to no effect on efficiency. +1 to splitting it up and doing a double batch sparge.

3) IMO it's always a good idea to have at least an extra gallon on hand. Since you already brew all grain, your volumes should be the same, so just prepare the same amount of water you normally would.

4) I'd guess you'll get pretty similar efficiency to what you get fly sparging. I know a brewer who got better efficiency when he switched to batch sparging, because his manifold and mash tun design had some channeling issues.

5) If you're referrring to draining the mash tun at full speed, then yes, that's how most batch spargers do it. It's part of what makes batch sparging so quick and easy. Just make sure you stir the mash really really well at dough in, and again after each sparge water addition, and I think you'll be very happy with the speed, ease, and efficiency you'll experience.