[denny]

Even if you like your beer very much, I agree that it's useful to consider processes/practices that might make it even better. But make sure you understand what a new step is supposed to do. Here, make sure you understand the purpose of mashing out. Only then can you decide if it applies to your brewery.

Mashing out does two things: it reduces the viscosity of the wort, making lautering easier; and 2) it denatures the enzymes so that no further conversion takes place, "locking in" the sugar profile.

It is mostly a holdover from when malt was undermodified. There could still be gummy beta-glucan sugars present at the end of the mash, and raising the temp made them less problematic during lautering. This had the side effect of better consistency between batches because conversion was halted.

These considerations might be important if you are mashing hundreds of pounds of undermodified malt and taking 2-3 hours to collect the wort. At the homebrew scale, they are negligible. I suspect that anyone who can tell a difference is just basing it on confirmation bias.

Mashing out won't hurt your beer but it is totally unnecessary.

i can understand that, though i do imagine increased wort viscosity could be important (that's my main reason as my efficiency is regular, but not amazing)

so, do you guys mash in a ~1.2litres/1lb ratio then just add more mash-temp water? or i guess just sparge directly with at ~165F?

Another case where there's a disconnect between theory and reality.  I've sparged with 170F water and 70F water and found no difference. It may affect viscosity, but it doesn't matter.

[RC]

Even if you like your beer very much, I agree that it's useful to consider processes/practices that might make it even better. But make sure you understand what a new step is supposed to do. Here, make sure you understand the purpose of mashing out. Only then can you decide if it applies to your brewery.

Mashing out does two things: it reduces the viscosity of the wort, making lautering easier; and 2) it denatures the enzymes so that no further conversion takes place, "locking in" the sugar profile.

It is mostly a holdover from when malt was undermodified. There could still be gummy beta-glucan sugars present at the end of the mash, and raising the temp made them less problematic during lautering. This had the side effect of better consistency between batches because conversion was halted.

These considerations might be important if you are mashing hundreds of pounds of undermodified malt and taking 2-3 hours to collect the wort. At the homebrew scale, they are negligible. I suspect that anyone who can tell a difference is just basing it on confirmation bias.

Mashing out won't hurt your beer but it is totally unnecessary.

i can understand that, though i do imagine increased wort viscosity could be important (that's my main reason as my efficiency is regular, but not amazing)

so, do you guys mash in a ~1.2litres/1lb ratio then just add more mash-temp water? or i guess just sparge directly with at ~165F?

It is inconceivable to me that wort viscosity matters at the homebrew scale and in this modern era of well-modified malts.

As Denny said, sparge water temp doesn't really matter. I get mine to ~180F. I'd go higher because it would shave off the time it takes for the wort to come to a boil, but I don't know what the plastic of my MT can handle. Plus my HLT does double duty as a pasteurizer. I don't want to go less because it would take longer for the wort to reach boiling temp. But strictly in terms of rinsing sugars, temp doesn't really matter.

While we're on the topic of sparge water temp, I'll add that the conventional wisdom that sparging with water above 170F will leach tannins out of the mash is completely false.

[denny]

Indeed it is, as long as your pH is good.  I have sparged with water just under boiling when I wasn't paying attention the the temp.  Didn't cause any problems.

[RC]

Indeed it is, as long as your pH is good.  I have sparged with water just under boiling when I wasn't paying attention the the temp.  Didn't cause any problems.

Not to mention that decoction-mashed beers should be horribly astringent if there was any truth to it.

[fredthecat]

Indeed it is, as long as your pH is good.  I have sparged with water just under boiling when I wasn't paying attention the the temp.  Didn't cause any problems.

Not to mention that decoction-mashed beers should be horribly astringent if there was any truth to it.

haha, thats a really good point. i remember discussion on this factor a long time ago and peoples answer was "it just doesnt cause astringency somehow" aka no real answer.

[denny]

Indeed it is, as long as your pH is good.  I have sparged with water just under boiling when I wasn't paying attention the the temp.  Didn't cause any problems.

Not to mention that decoction-mashed beers should be horribly astringent if there was any truth to it.

haha, thats a really good point. i remember discussion on this factor a long time ago and peoples answer was "it just doesnt cause astringency somehow" aka no real answer.

The answer is "because the pH is in the right range".