Re: [mnbrewers] Reverse Sparge? - mba

12 Feb 2003

I mash in a converted cooler.  I adopted the practice long ago (per Ellingson's
suggestion) of underletting rather than just a top down sparge.  This certainly helped
bump up the number of extraction points, but sorry, I don't have those numbers any
more.  The procedure I use is:
- circulate the first 2-3 gal., then pull off first runnings;
- underlet, stir (very essential), and let the bed resettle;
- circulate the next 2-3 gal., then start pulling off second runnings;
- sparge top down with remaining sparge H20, keeping the top of the grain bed covered with
H20.
I've had no problem with aeration nor tannin extraction.  My extraction rate is
typically around 26-28 pts/lb/gal, but I leave a lot of sugar behind.  To avoid high
tannins, keep temp of grain bed below 168F (I use 170F) and stop sparging when the pH of
the final runnings start to rise (I think you're good to a pH of 6, if I remember
correctly).
...
 Well, sort of not really.
Many brewers underlet (lifting the bed) to add hot water without aeration in a combination
mash/lauter tun.  By huge effeciencies, the laboratory maximum is beyond any brewery which
is about 34 gravity points per pound.  I typically extract about 28-30.  You extract
tannins after the sugar is extracted or if the pH rises.
R
 >> englandkris(a)hotmail.com 02/12/03 03:40PM
>>> I have heard about alot of the pro brewers using the reverse sparging
technique to get HUGE efficiencies.  From what I get, its where the
sparge water enters from underneath the mash and lifts it up.  They
then reset the mash again until it runs clear and then collect the
wort.  Anyone know anymore about this.  I would be worried about
extracting tannins but if you keep the temp 170F it should be fine, right?
Kris 
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Michael Valentiner, Minneapolis, Minnesota
mpv(a)yuck.net