I’ve been brewing for almost 10 years, but have mostly fly sparged except my first couple batches. With kids and work I’ve been trying to cut some time off my brewing sessions so I attempted a batch sparge this week. I literally brew two beers now of days and one is a DIPA that I typically get a 1.072 OG. I was surprised when i checked my gravity at the end of the boil and it was only 1.060. Shame on me for not taking a gravity reading before. The only difference was my sparging technique and I’ve read, and heard through podcasts where their shouldn’t be that much difference between the two. Typically I’d get about 82% mash efficency with fly and I only got 70% this time. My question is where am I messing up? I did two equal run offs through Beersmith and the second one was a 180 degree infusion which resulted in a 166 mash. I stirred it gently and let it sit for about 10 minutes before running it into the mashtun. Any thoughts?
The first thing to check with efficiency questions is always the crush. You might want to try to crush just a little fit finer and see if that solves the problem.
Another potential issue is mash pH. Ensure it’s within 5.2 to 5.5 (as measured in a room temperature sample). With batch sparging, if your mash pH is good then the sparge pH shouldn’t be a problem at all.
Another thing you could try with batch sparging a relatively higher gravity beer like a 1.072 DIPA would be to mash thick, like 1 qt/lb, and do a double sparge, aiming to get 1/3 of the boil volume from first runnings, 1/3 from first sparge, and 1/3 from second sparge. This would really maximize efficiency, and only takes a few extra minutes to do. By the way…
Waiting 10 minutes for equilibration after adding sparge water does nothing for you. Mix well, then start vorlaufing right away. It just doesn’t matter. Don’t take my word for it? Denny (as well as many others) will tell you the same thing.
When I batch sparge I completely drain the mash tun, measure the collected volume, subtract that from my desired boil volume, divide that by two, and do two batches with that volume of water.
I actually get better efficiency that way than fly sparging.
To answer the question, in addition to the things mentioned above, try not being too gentle with the stirring. The idea is that the liquor drained from each batch is uniform in concentration, so things like lautering slowly and other concerns of fly sparging are irrelevant. Just stir thoroughly, vorlauf, and drain.
Also helpful:
Mash at lower end of mash temp range and at least full 60 minutes
Sparge temp (grist + sparge water} = 166 - 169F
Stir well the sparge (before vorlauf/runoff) for at least 4 minutes
if doing single mash and sparge, shoot for mash grain ratio of 1.6 - 1.7 quarts water per lbs grain, and remaining needed water volume in the sparge.
For me (cheap n.easy batch sparge) for a 1.072 beer my brewhouse effciency is around 72 -73%. That includes a good crush and water manipulation.
My first question is, how sure of your gravity reading were you? Wort will stratify very quickly after the boil and if you collected you were gravity sample near the surface it will be low. Maybe your concerns are unfounded?
I’ll try a couple things mentioned here next time. Thanks for the suggestions!
My mash PH ended up at 5.28 and I measured the OG with both a refractometer at the end of the boil and a hydrometer after it cooled.
To contradict Dave’s advice, my efficicienynwent up with a thinner mash. I now mash between 1.63-1.75 qt./lb. and thwn batch sparge with whatever amnt I need to hit my boil volume. My last beer was 1.074 OG and I got 83% efficiency. pH makes a very small difference unless you’re way off. Like Dave mentioned, crush is always the first place to look. I crush very fine and I have no problem with astringency or stuck runoffs.
I have fmd that doing more than one sparge really has so little effect for me that I don’t bother woth more than one.
I agree with your points including this one. HOWEVER, I do think double sparging might help for some brewers, especially those who don’t crush as finely as you and I do.
I too mash usually at a ratio of around 1.5-1.75 qt/lb. But if my efficiency sucked then I might at least try going lower and sparge a lot more to see if it helps at all.
Given that you get higher efficiency with fly sparging, I think the major mash parameters (crush, pH, temperature) are probably in line and your losses are coming in the lauter. My first suspect would be incomplete draining of first runnings - did you verify that the runnings were actually equal in volume? Another possibility is that if you are saving significant time over fly sparging, you aren’t allowing for complete conversion that was previously happening during lautering. I always verify the gravity of my first runnings before I start running off.
If you plug your numbers into this calculator you can see how close you were to the theoretical efficiency: Batchsparge « SeanTerrill.com
As Kai used to say “the first wort is the best wort”. I’d rather get more out of the first runoff than the sparge. And I definitely saw a 3-5% increase in efficiency with a thinner mash.
Can’t find Seans forum name atm, but I wasn’t aware he had an online version. Would have made my work a lot faster.
I’m using a similar approach now, but when calculating lauter efficiency by the ratio of volumes, you need to account for the volume displaced by the sugar during the mash, which he appears to be approximating using the C=1/SG coefficient. I’ll need to check out his source code, as my calculator, which matches kai’s to a couple decimal places (floating points yo) is calculating a difference of 3-6% lauter efficiency. When I lower the absorption rate to 0.12, they’re pretty close though (.5-2%). Which matches the apparent absorption rate using preboilvolume - strike / grist mass.
You can get a better estimation using the following approximation
LauterFirstRunOffEfficiency ~= RunOffVolume / MashWortVolume
MashWortVolume ~= (0.0016005465398018200 * GrainWeight*GrainPotential) + WaterStrikeVolume
SecondrunningsLauter ~= SecondRunOffVolume / (MashWortVolume + SecondRunOffVolume)
TotalLauter = LauterFirstRunOffEfficiency + SecondrunningsLauter + etc etc
Priceless Brew in a Bag Calculator and Priceless Brew in a Bag Calculator
Again I agree. For maximum efficiency, it is indeed critical to drain every drop of wort out of the first runnings before sparging. This includes tilting the mash tun to get everything out. Takes a few more minutes but it’s worth it. Those who only drain off like 80% of the first wort before adding sparge water are losing efficiency. That’s a fact. I’m a good to the last drop guy myself.
Again, I agree, too. Gotta get all the first runnings when possible.
Absolutely! But my point was that getting more from the mash than the sparge is actually a good thing.
Don’t worry, I found you! 
That all sounds correct to me, but to be honest I haven’t looked at my own source code in 3+ years. I’ll try to dig into it a little more tomorrow.
Oh well that works. Let me know if you find any issues or have any questions. There’s a nice graph output, and calculator for measured vs expected on my calculator too. I had been considering calculating the apparent boil off rate and absorption rate as you did, but ultimately decided against it.