Just a quick question. When I batch sparge, up til now, I have been draining my mash tun rather slowly and allowing my second and third runnings to soak for 10 minutes before draining slowly again. I don’t remember where I read this process but this is my basic process. Tonight I went back and read Denny’s process for batch sparging feel like I’ve been doing it wrong all this time. If my iodine test shows conversion is complete am I correct in assuming that there’s no real benefit to the 10 minute soak and for a slow draining of my wort? I feel like all I may be doing is increasing the chances of astringency. Thanks for any input.
There is no need to let it wait and soak for 10 minutes and then drain slowly. All you need to do is add all of your sparge water, stir, open up the valve, vorlauf, and let it flow as fast as you can. The idea of batch sparging is to simply get all of the sugars in suspension and drain them out quickly. Fly sparging is slowly rinsing the grains. You can definitely cut some time off your brew day. Also, why are you doing three runnings?
Also the iodine test is not particularly helpful. Troubleshooting Brewhouse Efficiency - German brewing and more has a table showing what gravity you should be getting at the end of your mash. Also this may be helpful: http://braukaiser.com/download/Troester_NHC_2010_Efficiency.pdf
Yep.
And I’ve never done an iodine test. Don’t bother.
And I usually only mash for 40-45 minutes. And my beer usually turns out great.
Cool, thanks for all the info. As far as 3 runnings, it’s due to my equipment. I brew 2.5 gallon all grain in a 3 gallon Gott cooler. After 5-7 pounds of grain and about 9 quarts of water, my cooler is about full. I can do two sparges with about 1.5 gallons each and I’m good to go for a full volume boil.
The beauty of batch/no sparge is how quick it is! No need to runoff slow or wait the 10 minutes.
+1 Same here. I’ve never even owned iodine, and I’ve beer brewing for 21 years.
+2 to not bothering with the iodine test. It’s next to worthless.
There isn’t a need for a 10 minute soak per se, although I typically do use a 10 or 15 minute timer. That’s more to give myself a little leeway for other prep tasks or cleanup, though. I guess the real question is what you mean by ‘slow drain’. I typically have my valve open 50-75% once vorlauf is complete and then just keep an eye open for when it starts to trickle. Astringency is more likely to be extracted by the temperature or pH of your water or by oversparging. You can pretty easily measure the temp and pH with instruments, and you can pretty easily measure the last by taste. At the temperature of sparging, it won’t hurt to dip a finger into the stream and taste it. If it starts to taste like unsweetened tea, you’re better off stopping the sparge and just topping up with your brewing liquor.
haters are gonna hate. I batch sparge, I have experimented with batch sparge times. I batch sparge twice letting it soak for 20 minutes each time. To cut down time I once didn’t soak at all but my gravity was low. As a Biologist by education, I think the time allows for the remaining sugars in the grain to be drawn out(already converted). Think osmosis, the water outside the grain has less solutes then the grain. the soak gives it time to come to equilibrium via diffusion. I could be wrong but I know I have personally have seen my efficiency affected.
If your theory was true, then what I do wouldn’t work. Keep i mind that you’re stirring in your sparge water, so you remove the sugars and dissolve then in the water by doing that. I also use only a single sparge addition and average 83% efficiency. I’m glad you’ve found something that works for you, but you’re treating the symptoms, not the problems.
As a scientist (chemical engineer), here’s how I think about it in layman’s terms:
After the mash is done and you start the runnings, the sugars are already dissolved in the sweet wort (a scientist should think: “this is an aqueous solution”). The sugars both inside and outside of the grain materials are all dissolved and ready to flow. There are no sugar crystals sitting around in the grain bed undissolved!
It might help to start with this visualization: Take a glass of water, add a couple grams of sugar to it, heat it up in the microwave for a minute, and stir to fully dissolve. You now have a solution of slightly sweet sugar-water. If you then pour that into a pitcher and add a whole bunch more water to it, diluting it down, how long do you think it takes for the solution to re-equilibrate? Common sense might dictate, well, it’s virtually instantaneous – right? True!!
When you add more water to an aqueous solution AND you stir it up well for a minute or two, all those sugars that were already dissolved will almost IMMEDIATELY reach equilibration with the additional water. Wort is a little “viscous” (i.e., thick & syrupy), but it’s really not all THAT viscous to where it would inhibit fast dissolution, like honey or molasses or corn syrup would. It’s just not that thick, never will be.
So, you don’t need to waste 10 or 20 minutes or whatever waiting for things to happen. Conversion is done. Mash is done. Sugars are all dissolved, both inside and outside of the grain materials. They WANT to flow out of there and reach equilibrium. If you stir things up, just a little bit, you’re there.
Now, if you did a really crappy crush of your malts, I can see how waiting would matter. So, don’t do a really crappy job crushing your malts. Problem solved.
I’m not trying to sound like an ass. I’m trying to help explain real science in layman’s terms, in the hopes that it will open the eyes of some who couldn’t quite see it before in the same way.
Does one need to wait a few minutes after adding the sparge water for the grain bed to resettle into a filter bed? To avoid getting particles into the brew kettle
That is taken care of during vorlauf
I certainly don’t. I stir in the sparge water and begin vorlauf and runoff immediately. It will depend on your equipment, but you might as well try it.
Anecdotally, based on numbers I see here, it seems common for home brewers to be getting 80-90% conversion efficiency due to one or more mash parameters (time, temperature, crush, pH) being sub-optimal. If you see efficiency gains to due to a longer batch sparge time, you’d see (marginally, in most cases) better efficiency still by giving the mash rest enough time to fully convert. Or better yet, fixing the root cause of the incomplete conversion.
Of all the variables, crush is Numero Uno. Time and temperature are the most forgiving and barely make a difference at all with respect to efficiency – they each impact fermentability/attenuation far more than mash efficiency. If you have efficiency concerns, start with the crush, then go to water and mash pH, and save the marginal effects of time and temperature for last.
I like it. And best of all… gonna knock a bunch of time off of my sparge. 
+1
Great resources and info! Thanks for the links.