[ultravista]

I get fairly decent and consistent efficiency by mashing in a bag.

Perhaps a dunk sparge/mash out of sorts, after I drain the 1st runnings into the kettle and start the boil, add 168ish water to the tun, let it rest for 15-30 minutes, collect 2nd runnings, and add to the kettle.

It takes about 20-30 minutes (at a moderate flame) to get to the kettle wort, or first runnings, to boiling temperature.

I am wondering now if this process is affecting the fermentability of the wort.

For example, when mashing @ 149-150 for 'light body' and 'maximum fermentability,' is the absence of mash out effectively nullifying the lower mash temp process as the wort post-mash is slowly raised to boiling temp?

In other words, targeting a low mash temp without a mash out, is the slow heating of the kettle allowing enzyme activity to continue? Does this move the target above 150 therefore creating a heavier body with less fermentability and perhaps a higher post-ferment gravity?

I've read the mash out 'fixes' the wort and stops enzyme activity.

[kramerog]

You will get some continued enzyme activity during the heating to boiling thinning the beer out a little.  If you are generally happy with your results don't change it because of theoretical concerns.  If you want a bigger body then mash at a higher temperature.

For example, when mashing @ 149-150 for 'light body' and 'maximum fermentability,' is the absence of mash out effectively nullifying the lower mash temp process as the wort post-mash is slowly raised to boiling temp?

No.

[dmtaylor]

I think I understand what you're talking about, but I'll answer from several different angles just to make sure I cover your concerns.

If you're sitting at 149-150 F for a full hour before you pull the grain bag, etc., then raising the temperature towards a boil, fast or slow, will not hurt your fermentability at all really.  If the mash sits at 149-150 F for (let's be extreme) zero minutes, you basically just get the grains wet and then immediately bring it slowly up to a boil over 20-30 minutes, then yeah, your fermentability will suck.  Any mash greater than about 40 minutes will get you good fermentability.  Quicker than that, and fermentability will suffer a bit.

Mashouts are pretty pointless for homebrewers.  There's no need to bring things up to 170 F and hold for a few minutes for a mashout, if you plan to bring the whole wort up to boiling within like 30 minutes anyway, because then the mashout comes automatically in a timely fashion as soon as the wort hits 170+ F on its way up to the boil.

If you were to leave your wort sitting at 149-150 F for a long period while you perform a sparge, etc., then your fermentability will be high without a mashout.  This comes into play for partigyle brewing where you might leave the first or second runnings to sit for an hour if you can't boil both partigyles at the same time.  In these cases, a mashout might make sense especially for the smaller beer to prevent it from becoming extremely dry and watery.

It doesn't sound to me like you are doing anything outrageous, so I think the mashout is a moot point for you.

I should say, however, that I really don't think you need to rest your sparge water for 15-30 minutes.  That's a complete waste of time.  You can do a quick dunk, then immediately <2 minutes move your sparge liquid into the boil kettle.

[Wort-H.O.G.]

I think I understand what you're talking about, but I'll answer from several different angles just to make sure I cover your concerns.

If you're sitting at 149-150 F for a full hour before you pull the grain bag, etc., then raising the temperature towards a boil, fast or slow, will not hurt your fermentability at all really.  If the mash sits at 149-150 F for (let's be extreme) zero minutes, you basically just get the grains wet and then immediately bring it slowly up to a boil over 20-30 minutes, then yeah, your fermentability will suck.  Any mash greater than about 40 minutes will get you good fermentability.  Quicker than that, and fermentability will suffer a bit.

Mashouts are pretty pointless for homebrewers.  There's no need to bring things up to 170 F and hold for a few minutes for a mashout, if you plan to bring the whole wort up to boiling within like 30 minutes anyway, because then the mashout comes automatically in a timely fashion as soon as the wort hits 170+ F on its way up to the boil.

If you were to leave your wort sitting at 149-150 F for a long period while you perform a sparge, etc., then your fermentability will be high without a mashout.  This comes into play for partigyle brewing where you might leave the first or second runnings to sit for an hour if you can't boil both partigyles at the same time.  In these cases, a mashout might make sense especially for the smaller beer to prevent it from becoming extremely dry and watery.

It doesn't sound to me like you are doing anything outrageous, so I think the mashout is a moot point for you.

I should say, however, that I really don't think you need to rest your sparge water for 15-30 minutes.  That's a complete waste of time.  You can do a quick dunk, then immediately <2 minutes move your sparge liquid into the boil kettle.

+1  mash out or higher temp sparge water moves to denature sooner than later on the way to your boil.

+1 no need for sparge water to sit-just rinsing not converting

edit: here's some good info on this topic from braukaiser.com:

 Mash-out

Although mashing out or not is part of the chosen mash schedule its effect on efficiency should be discussed in more detail. Some brewers report a jump in efficiency when they perform a mash out. While this can be a result of improved lautering it is most likely the result of better conversion efficiency. If the enzymes in the mash were not able to fully convert the mash during the saccharification rest, a mash out can help the conversion efficiency by "super charging" the alpha amylase which works much faster at temperatures between 70 and 75C (158F to 167F). Above 80 C it starts to denature quickly. This super charged alpha amylase now converts the starch that has not been converted during the saccharafication rest and as a result the conversion efficiency is increased. But since the beta amylase is quickly denatured during a mash-out, the extract (i.e. efficiency) gained from a mash-out is mostly unfermentable and will lower the overall attenuation of the wort. As a result a mash-out should not be seen as a tool to increase the conversion efficiency unless the decrease in fermentability is taken into account.

Some authors contribute the extraction benefits of the mash-out to its ability to provide a temperature that gelatinizes even more starch (in particular the small starch granules which have a higher gelatinization temperature)[Scandrett, 1997]. But I have not seen a significant enough increase in the conversion efficiency by performing a mash out and many brewers report the same. While it is true that elevated temperatures will make more starch accessible, the additional amount that is made accessible in well modified modern malts is only small.

[pete b]

I agree that resting your sparge is a waste of time. I have been doing 2.5 gal batches biag the past 5 Wednesday nights after work and being able to do it fairly quickly is important to me because it is what allows me to brew every week. I usually don't sparge, I use the entire volume of water in the kettle. As soon as my timer goes off at the end of the mash I turn the heat back on, pull out the bag and put it in a big bowl, cover the pot, put on a plastic heat resistant oven mitt and squeeze the bag into the bowl and then pour that into the already heating pot.
Using this method I can do all grain batches of medium gravity or less in under 3 hours, including cleanup, and am getting exactly what I had hope and expected for in terms of fermentability of the wort.
I have also made a dark Belgian and last night I made an English Barleywine. For these I sparged because with the larger grain bills and longer boils the water and malt required it. I sparged by running 170 degree water through the bag slowly and immediately put it in the boil kettle.
The only reason I can think of in most circumstances to let the sparge sit is when batch sparging to let the sugars go into solution because that's what you are doing as opposed to rinsing the sugar off, and even that on a small scale probably only takes a minute or 2.

[ultravista]

kramerog, dmtaylor, wort-h.o.g., thank you.

My mash is typically 90 minutes. This time allows me to prep and do other things during the brew day. The tun is a 10 gallon Home Depot water cooler. While the lid is not insulated, it generally holds heat well if pre-heated. I also hit the mash with a paint stirring paddle & electric drill. This ensures a dough-ball free mash

I'll forego the 2nd running rest moving forward. It will speed-up the brew day a bit.

I was concerned that my process was somewhat effecting fermentability and negating the low mash temperature.

I've got a Pliny on-deck next week. Can't wait.

Should I shoot for quick heating of the first runnings to stop enzyme activity?

[Wort-H.O.G.]

kramerog, dmtaylor, wort-h.o.g., thank you.

My mash is typically 90 minutes. This time allows me to prep and do other things during the brew day. The tun is a 10 gallon Home Depot water cooler. While the lid is not insulated, it generally holds heat well if pre-heated. I also hit the mash with a paint stirring paddle & electric drill. This ensures a dough-ball free mash

I'll forego the 2nd running rest moving forward. It will speed-up the brew day a bit.

I was concerned that my process was somewhat effecting fermentability and negating the low mash temperature.

I've got a Pliny on-deck next week. Can't wait.

as long as your getting full conversion during the mash-should be good to go.

[klickitat jim]

Seems like the amount of time to rais the mash to 170 vs putting it in a BK then head toward boil temp, same same. BK might be quicker since its just wide open flame with no scorching concerns.

I "rest" my sparge (recirculate actually) just long enough for it to clear up. I'm notbworried about extra conversion, extra lautering maybe, but if im trying to get extra conversion then obviously I didnt mash right.