why should sparge water be 170 degrees. is this just a general guideline as in "hot enough to make the sugar drain easily but not hot enough to get weird flavors", or is there another purpose.
Besides the reasons already listed hot sparge water conserves fuel, taking less heat to boil.
But you are saving fuel on heating the sparge water. Energy cannot be destroyed or created, only converted. So Id think you are using relatively the same ammount of fuel. You have to heat either the sparge or the boil more, so it is a wash.
Until more evidence is provided regarding viscosity, etc. I will continue to sparge around 170. I need more proof from our resident mythbuster; Kai.
Look at the big breweries. They basically grind grain to flour then use a mash filter to filter out the grain husks etc. Not sure why they don't taste astringent as hell. BMC-Labbatts/Molson may taste like crap to many, but it isn't because of astringency. I do know they get about 98% efficiency.
I'm not sure why they would be astringent. Homebrewers who do partial mashes in a nylon bag or who do all-grain brew in a bag use much finer grinds to help efficiency, and don't have any problems with astringency.
Astringency could come from too much heat, but just grinding the grain finer seems like it should help efficiency without negative effects.
I think the coarser grind is mostly a product of the sparge systems that 3-vessel all grain brewers use that can get stuck with finer grinds. They're to compensate for a problem elsewhere in the system, they're not necessarily the best way to do it.
I've done a couple brew-in-a-bag brews with very finely triple-crushed grist (and averaged about 85% efficiency into boiler) and haven't detected any astringency yet. there was a fair amount of flour, but it certainly wasn't all powder. I'm not convinced that shredded husks really present a significant possible source of tannins, provided the temp and pH are right for the mash/sparge
That's a decent hypothesis...now all we need is someone to grind their grain to powder and test it out! I recently reduced the gap on my Barley Crusher from the default .039 to .031. My conversion efficiency has definitely been better, with no noticeable astringency. The crush is very fine now, with a ton of flour but I've had no problems with lautering or stuck sparges, but then again I use one of Jaybirds false bottoms that have quite a bit of surface area.
I'm leery of making the crush any finer...I'd rather not ruin a whole batch of beer just to find out if I can gain a few more % efficiency. Repeatability is a lot more important to me than high efficiency at this point.
... A general rule is to terminate the sparge when the pH of the collected wort increases much beyond 0.1 pH units higher than the mash pH. In any case it should not exceed 5.5.
Application of this general rule usually amounts to 1 to 2 Plato extract left in the gains.
If the sparge water has an alkalinity in excess of 50 mg/L as CaCO3, then the Ph will quickly approach the critical point. High temperatures also increase the extraction of undesirable compounds, the critical temperature being about 77c. Thus, best results are generally obtained with a sparge in the range of 74 to 75c and with water whose alkalinity is as low as possible (25 mg/L or below).
Until more evidence is provided regarding viscosity, etc. I will continue to sparge around 170. I need more proof from our resident mythbuster; Kai.
Enter your email address to join: