If my mash tun can hold enough water after my mash has converted, would I be able to add and recirculate the entire pre-boil volume and then drain? I have been fly sparging but Santa brought me a new (bigger) mash tun so I am thinking about trying this out this weekend. Thoughts?
Sure. You might suffer a bit of loss in extraction or rinsing away the sugars. Try it and see.
What are you thinking this will accomplish? From a strict chemistry standpoint, two smaller extractions are more effective than one larger one. All of your water already contacts all of the grain, only the sparge will be more effective on its own. Some people espouse the benefits of no-sparge, but they’re not typically raising their mash volume.
What you are proposing is basically no sparge brewing. It works great, but your efficiency will likely take a hit.
I am just thinking about saving some time. I am using a RIMS set-up and if I am adding all of the sparge water to the mash after conversion and recirculate for 15 - 20 minutes, I am “rinsing” the grain bed right? But everything I have read is that the no sparge technique is the least efficient method. I’m not sure I understand why though. After mashing you have a saturated sugar solution - first runnings. Then you add your sparge water either by fly sparging or batch sparge and extract the sugars that are left behind. With the no sparge technique is it because the extra sugars do not enter the comcentrated solution easily? Or does the no sparge technique have the brewer use all of the water during the mash resulting in a thinner mash and less effective enzyme function?
compared to a 2 run-off batch sparge the no-sparge should loose you about 7-8% in lauter efficiency.
I don’t think the mash will be too thin for the enzymes to work efficiently. I found that starch conversion does happen faster and tends to be more complete in thinner mashes.
Kai
It’s because sparging is about dilution of the dissolved sugar held behind in the grain bed.
Imagine that 100% of the sugars dissolve in the no sparge, but you can only drain 75% of the water because of the water absorbed by the grain. You’d get 75% efficiency.
Imagine instead that you take two runnings, from your first you get 60% of the sugar, because you drain less water and leave the same amount of water behind, but more proportionally. Then you add and drain your sparge to get 60% again of the 40% you left behind. The result is 60% + (60% x 40%) = 84% efficiency with a sparge.
That’s reasonably close to the numbers I get with the two sparge techniques on an average gravity beer.
With all due respect…I am raising my left eyebrow here… ???
Kai I think he’s talking about mashing then adding in his sparge water afterwards, but before draining. Like a giant mashout.
But I was just reading that some commercial brewers use as high as 3qt/lb in their mash without conversion suffering. That was higher than the 2qt/lb I’d seen as an upper end for safe mashing. I think they do this so the mash is more easily pumped, but it does expand the usable range for us homebrewers. Especially those who like a no-sparge for the ease. Those who like no-sparge for the higher flavor to fermentables ratio, probably wouldnt’ want to dilut it with this thin of a mash.
Oscar, you didn’t understand malzig’s explanation of how two rinsings is better than one? Of course I’d probably raise an eyebrow if you described some simple aspect of commercial aviation.
I understand why rinsing twice will improve sugar extraction. I didn’t understand his logic/math.
Tubercle raised an eyebrow too but it was because the logic/math DID make sense.
I’m scared now.
Wasn’t there some talk on here a while back about some kind of super sparge or something like the OP is talking about?
To be honest, if I could avg 70-75% eff doing one sparge then that would be my method. I’d be happy with those numbers. Maybe mashing 1.2 to 1.5 qt/# then upping it to 3 for the sparge and lauter would work.
Yeah I was scratching my head too because the math made sense. Still does. 
OK, this post is for those who are not brewing geniuses,
Yep, math hurts my brain… In “Radical Brewing”, Randy Mosher talks about how hard it is to get really high gravities from a particular mash, which makes sense because water can only hold so much sugar (saturation)… Is this the same reason that a no-sparge method would yield a lower efficiency?
Well if it makes sense to you all I will write it out, make some diagrams and try to get my head around it. Prima facie it makes no sense to me, but that may say more about me than about the math.
Hope this doesn’t turn into the efficiency thread…
If you are interested, there is some info on this here: Batch Sparging Analysis - German brewing and more
including some graphs.
Kai
Danke schön.
Bitte schön.
The nice thing about batch sparging is that it is easily modeled and that one can actually predict the lauter efficiency based on a few parameters like grain absorption and water use and run-off size.
Kai
Boy, I wish my no sparge efficiency only dropped that much! I go from 85% with a single batch sparge to somewhere between 55-65% with no sparge.
The difference is dependent on the qt/lb and whether you add water to mash out. At 2qt/lb and using 0.125gal/lb bound water, you are looking at a partitioning of 0.125gal bound/0.5gal total. You get 0.375gal drained which is 75%.
At 1qt/lb, the percentage goes down to 50% (bound is half the total). At 1.5qt/lb its 62.5%.
The more you leave behind to begin with, the more you’ll pick up from the sparge.
My last 8-9 batches have been 5.5 gallons vs. my typical 11. Having the extra head space in my mash tun (70 quart extreme) I’ve been doing exactly what the OP asked about. After I’m done mashing (usually 60 minutes) I’ve been adding the required amount of sparge liquor to get my desired preboil volume and then recirculating for 15 minutes. My efficieny has dropped slightly, but not that dramatically. For an 11 gallon batch where I would do two run offs from the tun I typically would see anywhere from 76-82% efficiency depending on the recipe. These 5.5 gallon batches where I’ve been adding all the sparge water prior to run off I’ve been getting right around 72-74% efficiency. Nothing an extra pound of base malt won’t fix were I concerned about the drop. But it isn’t significant enough that I care.