General Category > All Grain Brewing

Fly Sparging

<< < (2/6) > >>

mabrungard:
My sparging technique is similar to Jeff's.  There is one component that I disagree with, the mash bed cutting.

Those that know me well are aware that I'm a geotechnical and environmental engineer.  I've had extensive education and training in flow through porous media (soil).  The parallel is that a mash bed is porous media too.  Penetrating a stable bed of media with something like a knife would actually increase the likelihood of flow short-circuiting, not reduce it.  The thing that the cutting would provide is increased permeability through the bed (by the increased short-circuiting).  I highly recommend that anyone that performs this misguided technique should try NOT doing that for their next mash.  The runoff may be a little slower, but you won't have to worry about short-circuiting.  I don't know where this wive's tale came from, but its not doing what you think it is.

PS: Pro brewers don't do this either.  But its probably because in large tuns, there is no way to 'cut' the mash.  But they also know that its unnecessary.

conley:
In any of my experience i have not ruined a batch by cutting my bed of grain. its not something i practice with every batch, but its never created a channel, as long as they are thin cuts.

although your educational expertise indicates this is a "wives tale" i'm going to find out some ways i can practice this on a home brew scale now that is has got me thinking.

Where have you read that no Pro Brewers do this, as there are many brewers out there and everyone seems to have different opinions, even the  pros?

jeffy:

--- Quote from: mabrungard on January 05, 2013, 06:02:42 PM ---My sparging technique is similar to Jeff's.  There is one component that I disagree with, the mash bed cutting.

Those that know me well are aware that I'm a geotechnical and environmental engineer.  I've had extensive education and training in flow through porous media (soil).  The parallel is that a mash bed is porous media too.  Penetrating a stable bed of media with something like a knife would actually increase the likelihood of flow short-circuiting, not reduce it.  The thing that the cutting would provide is increased permeability through the bed (by the increased short-circuiting).  I highly recommend that anyone that performs this misguided technique should try NOT doing that for their next mash.  The runoff may be a little slower, but you won't have to worry about short-circuiting.  I don't know where this wive's tale came from, but its not doing what you think it is.

PS: Pro brewers don't do this either.  But its probably because in large tuns, there is no way to 'cut' the mash.  But they also know that its unnecessary.

--- End quote ---

I learned that from Jeff (hopfen) who learned it at Sierra Nevada beer camp, so there's at least one major pro brewer that needs your expertise.
I have found that it helps when there is a lot of fine particulate on the surface of the grain bed.

narvin:
Commercial mash tuns are going to be a lot deeper, so raking the surface of the mash to disrupt coagulated protein (teig, or top dough) is going to have less effect on the grain bed itself.  That being said, in a cooler I wouldn't go more than a couple inches deep or you could have channeling.

Don't Worry Be Hoppy:
Thank you all for the input. I have a better understanding of how to fly sparge. Brew On!

Navigation

[0] Message Index

[#] Next page

[*] Previous page

Go to full version