I’ve read multiple posts on this forum as well as Denny’s recent article about batch sparging.
I get and agree with the whole “equal-concentration-of-sugars-throughout-the-mash” idea.
I have a hypothetical question regarding the lautering (or sparging) aspect of the process:
Assuming no change in temp, SG, wort composition, grist crush, etc., it seems that a larger drain surface area and/or shorter distance the wort must travel to get to the drain would be critical in terms of lautering (or sparging) speed.
What designs work best and why? Has anyone ever tried a 3-D sparge manifold? Why not?
I have a 10 gallon round Rubbermaid/Gott/Igloo cooler which can result in a grain bed of considerable vertical depth (e.g., up to the 8 gallon mark for high gravity beers using 25+ lbs of grain). Lautering/sparging seems to take longer. I suspect it has to do with grain bed compaction given its 12-18+ inch depth.
Hypothetically speaking, would a mildly domed 12-inch round SS false bottom with a 12-inch SS bazooka braid attached vertically help speed up batch sparging in a 10 gallon round cooler?
Sorry to not really answer your question, but being the pragmatic type I am, switching to a rectangular cooler seems a much simpler solution. But hypothetically, I’d guess you’re correct. But that’s a difficult solution compared to a new cooler!
Theoretically, it would seem like that would speed things up. Not sure about a 12-inch weenie sticking up into your mash, though - seems that could make stirring a bit of a problem
Yeah, Denny, you’re right. That would be the far more practical thing to do.
I do have a big rectangular cooler, … but it is red (… big sigh :-).
Hoeker–you’re also right. A “12-inch weenie” would probably get fractured or bent while stirring a stiff mash.
I does give me a different idea, though: Instead of the stiff bazooka screen what if there was a flexible SS hose braid (like what Denny uses) with the end crimped and a long string attached to the end of it. Let it be flaccid during the mash and then pull it taut vertically when it is time to “perform” the lauter/sparge?
Sorry for the double entendres–it did start off as a legimate academic question…
Look, I’ve gotta say that other than as a hypothetical exercise, this idea just isn’t practical. Why go to all that effort when you can just build a new cooler?
I’ve experimented with this numerous times and the braid gets no “suction” at all. That’s why the length of braid doesn’t really matter. All the draining happens where the braid attaches to the outlet. You can prove it by filling your (rectangular) cooler with water and lifting the braid out of the water as it drains. No change in flow rate.
that’s what I was thinking - the braid acts as a filter, not a straw - the wort closest to the drain is being sucked out first - no different than if there were no braid at all. I think a lot of people assume it is being sucked evenly along the braid like a manifold, which is not the case
Denny & blatz, that’s exactly the reason I shortened the braid in cooler. And now I have the added benefit of not having an obstructive braid in the way when I’m stirring my mash!
Consider this- that while lifting the braid up doesn’t alter flow rate because the max volume of fluid is exiting the drain restriction at any given moment until almost all the wort is gone.
Yes, as long as the maximum flow rate into the braid is faster than the flow rate out the end, raising the braid won’t change it. But if you reduce the available surface area too much with a tiny braid, a tiny mesh, or if it gets clogged, then it will alter the flow rate. If clogging is a problem then having a longer braid will help because there will be more surface area for the wort to flow through.
But Denny has said in the past that he tested various lengths of braid and it makes no difference in his system, and based on the other thread he is crushing pretty fine, so I can’t imagine you’d have any real issue.
I recently started doing no-sparge batches, and had to shift to my 150 quart cooler to be able to hold the entire grain bill plus all the water to make my pre-boil volume.
For a thirty pound grist, the grain bed depth was 4 inches. I ran off 15 gallons of wort in 15 minutes, and it ran very clear after vorlauf.
I have no frame of reference for what are normal run-off times when doing no-sparge and batch sparges.
Can anyone elaborate for me? Denny, surely you know by heart how long to expect a batch to run off based on volume going to the kettle.
My guess is that so long as its not a stuck mash, grain bed depth has no effect on run-off speed for batch sparging.
Based on my current knowledge, the OP would do well to set up his rectangular cooler as a mash tun. It can’t hurt to have both available, and as posted by others, it’s a simple and cheap thing to do.
The one time I really timed it, it took 15 min. form the time I started the mash runoff til I finished the sparge runoff. That includes the mash vorlauf, stirring in the sparge water, and sparge vorlauf. That was for 8 gal. of wort in the kettle.
Mine was timed after vorlauf…and was non-stop with a fully-open 1/2" full port ball valve. Assuming that your pause to re-fill, stir, and vorlauf took half the 15 minutes, and that your volume was roughly half mine, the rates of actual wort drain-off were very similar; around 1 gallon a minute.
Hmmm… I’m listening to everyone’s comments.
And, yes, being a practical person, I probably will switch to a rectangular cooler.
My intuition still tells me that grain bed depth does make a difference.
Seems to me that when it gets thicker in the sense that lower grain to water ratio efficiency suffers. Which is what happens when brewers have maxed the tun capacity out.
All these comments are very interesting and thought-provoking. Depending on the sources, it seems that, for the homebrewer, the ideal grain bed depth is between 4-12 inches. Perhaps counterintuitively, a deeper grain bed is more “efficient” (up to a point), but not necessarily “faster.” See JP’s HTB Appendices E and F for more details, if interested.
A grain bed depth beyond 12 inches might have compaction issues in a 10 gallon round Igloo cooler (internal dimensions 12 inches diameter x 18 inches deep) given that the height would then exceed the width of the grain bed. That situation (i.e., grain bed height exceeding its width) does not occur in a rectangular mash-lauter tun regardless of lauter design (e.g., false bottom, pipe manifold, or screen) or grist amount (e.g., high versus normal gravity recipe).
My personal observations with the high gravity brewdays seems to suggest slower lautering. But, there are too many other potential variables (different recipes, different wort temps, mill gap settings, coarse vs fine grist, use of wheat, etc.) involved in order for me to really be able to say for sure. So I certainly respect the views of those with far more experience. Nonetheless, being a practical person, I think the hypothetical 3-D MLT design isn’t.