Mash rakes and low oxygen

[IceChisel]

Are mash rakes compatible with low oxygen brewing? I can't imagine a mash rake in an enclosed environment causing wort "shear stress" like a pump...?

https://www.homebrewersassociation.org/forum/index.php?topic=28739.0

 

[Schlenkerla]

I don't know of anybody using rakes who do LOB, at least not at the hobby level. I used a mash paddle for a year before switching to pump and then a HERMS. The pump was mostly for recirculating at lauter time. HERMS kind of changed all that. A rake I guess is OK, if you do it quickly and intermittently and you have the metabisulfites for protection. How are you mash capping?

 

[IceChisel]

Don't currently own a brewing system, so no mash cap but was just curious if there was any adverse effects.

 

[RPh_Guy]

As far as I can tell, shear stress only matters if you're filtering. With high shear stress the beta glucans bind together and increase viscosity, which makes filtering more difficult. There's no evidence to suggest this occurs in a home brew system; the thread you linked seems reasonably convincing that it doesn't matter (thanks mainly to @Die_Beerery ).

On the other hand, it would be considerably difficult to design a mash stirring system and maintain low oxygen, and you would still want to do some pumping in order to get clear wort.

 

[day_trippr]

I dunno...Die_Beerery uses a lot of gas purging - of pretty much everything in his system.
Seems to me a rake could be easily accommodated if one is willing to go to that level

Cheers!

 

[RPh_Guy]

I dunno...Die_Beerery uses a lot of gas purging - of pretty much everything in his system.
Seems to me a rake could be easily accommodated if one is willing to go to that level

Cheers!

Read the linked AHA thread, he did test a stirring gadget instead of pumping.

 

[day_trippr]

I wasn't commenting on efficacy, just implementation...

Cheers!

 

[RPh_Guy]

I agree stirring is compatible if you can avoid additional wort-air interaction somehow.

"Easy" isn't a word I'd use, but if it's easy for you, we'd all appreciate more data on the subject.

Then the question becomes "why?"
Regardless of how easy it may be. The only reason to implement such a process is for a perceivable improvement in beer quality, which hasn't been demonstrated. Maybe your experiment will have different results.

 

[Die_Beerery]

I have a stirring mechanism, that is on a VFD, and sealed. So yea it can be done.