Dual mashing?

I just had this thought a few minutes ago, so I thought I thought I would see what y'all thought. Logically speaking, it would seem that doing a second mash instead of a batch sparge would increase efficiency without risk of using too much water or extracting unwanted stuff into the wort. My gut, OTOH, tells me there's got to be something wrong with it. I have to imagine that in all the thousands of years we have been brewing, someone would have tried it. And if it were a good method, it would have a presence in the brewing community. I would at least like to try the method on my next batch, but if someone gives me a good reason not to do it, I would be thankful to them for saving me from doing something stupid. Thanks.

-AJ

i would be curious as to your results. nothing is greater at disproving theory than results. that being said (and please, someone correct me if i'm wrong) the mash itself is the actual process that converts your grains' starches to sugars. once the actual conversion is done, no more "mashing" can occur. the sparge itself is just rinsing your grain, and getting all the sugars that are left behind by the first runnings.

So are you emptying your mash tun and just doing a completely new mash? It wouldnt be cost efficient really and you would end up with a high gravity wort.

Like Eggbeater59 said the conversion has already taken place... so if you plan on mashing for another hour after you drain off the first runnings you are addind an unneeded step.

That is correct, but I don't think you can get 100% conversion from a single mash. Otherwise, typical efficiencies would be much higher, or so I would imagine. The theory is that you'll get closer to 100% conversion with a second mash. Barring any comments that disprove my logic, I will try this on my next brew and let everyone know how it turns out.

-AJ

personally i dont think it would be worth the extra hour to mash but expirament away and post back results

here's some good basic info http://www.howtobrew.com/section3/chapter14-6.html
i do think that if you were doing decoction mashing you might see some different results. for single step mashing w/ grains that have enough diastic power for conversion, i don't think you'll see an increase in efficiency. basically you're just doing a long batch sparge.

OK, after reading that link I basically took away that I could probably get the same effect as what I proposed by mashing a little longer, say 75-90 minutes vice 60 minutes combined with a little thinner mash, say 1.75 qt/lb? Thanks for the prompt replies and pointing out the error in my logic.

-AJ

nukebrewer said:

Thanks for the prompt replies and pointing out the error in my logic.

-AJ

Click to expand...

bah, these are the kind of questions that spark brilliant innovations. humanity would never evolve if the people with the "well what if we did it this way..." thoughts kept it all to themselves, whether that be due to fear of witch hunt, bad tasting beer, or getting kicked to the couch yet again...

I think its a good idea, and thats mainly because I literally had the same thought yesterday! Heres my thoughts on the matter: once I had too much sparge water left over after I was done w/my mash. My final runnings were 1.008 into the boil pot, and I just threw in all of the extra sparge water into the mash tun, and left it. A few hours later when everything was done and I was cleaning up, I took a reading from the mash tun, that last read 1.008. It was at 1.030!! Now I don't know if this is a testament to longer mash times, or some sort of 2nd mash. But I think its both. Adding the fresh water I think really helps finish the mash and really convert almost everything. I think we're on to something! For the record my efficiency is around 77% so its not like I just mashed out too early and left all the sugars behind the first time.

You actually can approach 100% conversion efficiency in any proper mash. However, it's losses due to lautering efficiency, absorption, dead space, etc that decrease the overall efficiency number from 100%. Additionally, in order to approach 100% efficiency, one would likely need to crush the grain very fine and sparge quite a bit more than is really recommended, thus putting the pH well outside the normal range and extracting tannins. Simply adding grain and water to an already run off mash will not increase the overall efficiency, but will likely result in decreased efficiency, despite collecting stronger wort from the second runnings.

Lots of great reading here: http://braukaiser.com

punk_rockin - you likely didn't get more complete conversion with your last step. Instead, you accomplished yet another very thorough batch sparge, rinsing even more sugar from the mash. Did you taste the runnings? There's a good chance that the resulting wort didn't taste good due to the problems associated with oversparging.

The goal should NOT be 100% efficiency. It should be good, quality wort with a proper flavor profile and proper fermentability for the style. 60% efficiency is fine if the wort is of high quality and the resulting beer is excellent. On the contrary, 95% efficiency sucks if the wort is full of tannins, attenuates too much, and results in poor beer. Consistently hitting lower efficiency numbers while producing high quality results is far better than striving for very high efficiency and getting inconsistent or even poor results. Use the info and spreadsheet at the link I provided in my last post to analyze your techniques, figure your losses, and determine if there is anything you can do to improve any given step. Hint: read up on conversion efficiency vs lauter efficiency.

The technique suggested in this thread, while perhaps slightly misguided, is not without merit entirely. In fact, it is common practice when partigyle brewing to add some grain and accomplish a short rest prior to collecting the second runnings.