Recirculating While Mashing In

[Brewmegoodbeer]

While watching the linked video, I realized, that they left the mash recirculating while mashing in at 4:45 in video.



I always thought that this should be avoided to assure that you get all the dough balls out, as the suction of recirculating will want to keep compressing/setting the grain bed. Any noticeable/negative differences between leaving it circulating while mashing in vs closing the valves? Recirculating while mashing in gives the opportunity of the HERMS system to regulate the temperature loss from adding grain simultaneously and I like this idea because you can heat herms system to exactly mashing temp and just mash in instead of worrying about a higher “strike temp”.

 

[bobeer]

I used to brew on the Blichmann breweasy at my brew shop. I really didn't like the circulating mash with that specific system's setup. Yes, it helped with the mash temp, it kept it to within a degree, but you had to use much more water than you would with a regular mash in a cooler since the heating element in the breweasy always needed to be submerged when it was heating. I always had issues finding the right flow to keep enough liquid in the hlt yet to still have enough to mash the grains with up in the mlt/boil kettle. Mashing out took a while too.. I'd rather just batch sparge.
As far as the dough balls went I recall mashing in while the pumps were off so I could mix it all up well. Once it was all mixed up I turned the pumps back on. I think this process sort of depends on your system and how it all works but I could be wrong.

In all honesty I've only use this one HERMS but I was happy to go back to my cooler mlt. The strike temp app on my phone always nails the strike temp so that's never been an issue with me. I just preheat my mlt with a little of the hot water as it rises to temp. No pumps to get clogged or heating elements to troubleshoot. No nooks and crannies to clean, etc...

 

[Staticsouls]

I don't think you will see any efficiency changes with that method vs underletting or the normal dough in method so long as the dough balls are broken up, mash temps are on, and ph level is where it needs to be.

 

[eric19312]

Wow clearly that beer has been ruined. See how high up on the side wall the recirc return is coming in? No mash cap. All that headspace above the wort. Nasty oxidized wort for sure.

Well maybe they aren't sensitive to the poor flavor that is surely there.

Anyway I gave up my ability to recirc during dough in when I started underletting. I now heat my strike water in my BK and underlet the mash in my tun using my mash pump from kettle out to mash tun out. Once the strike water has transfered I do a quick hose swap and reroute my mash-out to the mash pump and from there to mash-in and start the recirc pump, slowly for about 30 seconds to set the grain bed, then up to about 2 GPM for the duration of the mash.

Before I started underletting I did use my mash recirc system to make sure my strike water was at the right temperature and my mash salts were well mixed. But I always killed the pump during actual dough in and then started it (again very slow at first).

When underletting I find the temperature of the grain bed (especially at very top of grain bed) will tend to be initially lower than the temperature under the false bottom. The water under the false bottom will be at or near strike temperature. The top of the grain bed will be much lower than strike temperature. Once I start circulating that hotter water from under the false bottom is delivered to the top of the grain bed. About 5 minutes into mash temperatures are pretty stable and hold within about 1-2 degrees F. I believe this is good enough. My typical mash profile is a stepped mash starting at 145 for 45 minutes, then ramp to 160 over 15 min and hold for 15 min then ramp to 169 over 10 min and hold for 10 min. I've made some highly fermentable worts with this schedule so am not concerned that I am denaturing my beta amylase enzymes to any significant degree during this period.

 

[Smellyglove]

From my experience with two different false bottoms recirulating while mashing in is a horrible practice as the risk of getting a poor flow or stuck is multiplied through the sky comparing to just keep pumps off, mash in, stir, let grainbed naturally settle for 10-15minutes, then start pump.

And, are those pumps oriented so the inlet is from the top? And purge valves on the bottom? Wow! Either there is something pretty fundamental which Ive missed, or the air in their environment must be heavier than water.