It is no sparge, in essence… all the water is used in the mash runoff, and there is no separate sparge. It is no different than dumping all of your remaining water into the mash tun before vorlauf. It requires a pump, though, but the tradeoff is that you can use a smaller mash tun. And it is also susceptible to channeling issues like fly sparking.
His numbers sure seem to be better than any no sparge I’ve ever done.
He “may” be getting a higher efficiency by the use of a “sparge” as opposed to simply draining the tun, but my no-sparge yielded a 64% efficiency. Now it may depend upon how his pump is setup. If the wort stratifies (and we all know it will), and if we suppose he is pulling from the area with the lowest sugars, he is in essence sparging and collecting in the same vessel and may be maximizing his efficiency by inadvertently taking advantage of the natural stratification.
Based on these statements:
“5) Pump the now liquor/diluted wort from the kettle back into the tun in a continuous recirculating loop
6) Take a refractometer reading every 5 mins until the gravity stabilizes and then let the wort in the tun run off. This usually takes about 20 minutes with a 10 gallon batch.”
I find it hard to believe that he’s getting stratification since he’s recirculating the wort and he’s checking for gravity stabilization.
I think one thing to consider is the residual sugar remaining in the liqour in and around the grain bed
once the bed has been drained.
Washing the sugar from the grain bed is key to good efficiency.
This entails incorporating a thourough rinsing of the grains.
If there is significant liqour remaining in the grain bed, this may negatively impact the mash efficiency.
But data is needed to verify.