Just today Brulosophy just posted this experiment with interesting results, specially the clarity between the batch sparge and the no sparge. For the experienced home brewers, what do you think of the results?
Please keep in mind that it’s only a single data point. The key to validity in citizen science is repetition. Don’t take this, or most any experiment done by Brulosophy or Experimental Brewing, as the final word. For instance, the difference in clarity could be from a number of things. A single trial is only the starting point, not the end. Try it yourself and see what you find.
The author acidified the sparge water by quite a bit. I wonder if that has anything to do with the haze.
Another possible cause could be the second stirring required. I love press pot coffee and the key to a good clean press is to only swirl in the beginning and NEVER stir before the press. Maybe something similar is happening here.
I doubt it’s the stirring. For that matter, I doubt it’s the batch sparge. Too may people make crystal clear batch sparged beers for that to be the difference.
No doubt, just pointing at possible causes.
The difference in clarity is evedent in the post fermentation, pre gelatin pictures. My first thought was chill haze or a varible with the gelatin process. But perhaps it is a yeast performance issue?
It could be a number of things, which is why it’s kind of a meaningless indicator with only a single test.
Yeah, lots of variables involved to make any sweeping pronouncements. All I know is that I can get crystal clear beers batch sparging. Works for me. 
I think something else is going on. Maybe some unintentional difference in the gelatin application method.
I find the only 2 point gravity difference between batch and no sparge to be interesting. I expected a bigger difference in efficiency.
I too am intrigued by this. Should be at least a 10% efficiency swing in my experience if not way more. Otherwise I have to wonder if they did it right! Brings the whole thing into question.
That said, I am not at all surprised that tasters could reliably detect some difference, given the benefit of the doubt that the no sparge truly was not sparged etc.
Efficiency loss from skipping a sparge depends on how strong the beer is. Light beers use a small amount of grain, so loss of wort to grain absorption is smaller than for a strong beer.
Full volume mashes also leave nowhere for doughballs or air pockets to hide, which helps counter the lower efficiency.
I regularly skip the sparge for light beers with under 4.5% abv. Not just for time saving but also for clarity as I think the cloudiness from sparge runnings can persist into the final beer as haze or excess body.
I haven’t found your first point to be true. In a high gravity brew, you will lose a lot of efficiency even with a sparge but with no sparge or a “poor” sparge where I only pour a small amount of water over the grains for 1 minute my efficiency has never dropped below about 55% even for a big beer.
Also I too regularly do no sparge for small beers simply because my efficiency is already close to 90% with small beers so there’s no point in making it any “worse” by taking it to 95% or more!
I have never had a problem with cloudiness from batch sparging. I use gelatin on every batch. The beer is crystal clear 1 week after kegging 99% of the time. I don’t think the 1% of the time the beer takes longer to clear is due to batch sparging.
That’s not really a lot of 10% phosphoric acid. According to BrunWater it will neutralize about 75 ppm of bicarbonates. Plus, I don’t see how a lower pH in the sparge would so anything but prevent tannin extraction.
The sparge volume (8.75 gal) being much larger than the mash volume (3.75) is non-optimal efficiency wise.
What was the temp of the sparge?
Ah… I was thinking 88% lactic.
Dave, Dave, Dave…these results, whether from Brulosophy or Experimental Brewing, should ALWAYS be in question! All we can do is orovide some data points based on our investigation to point you in a direction to find out for yourself. No one should take any of these as absolute gospel.
Doesn’t matter a whole lot.
Doesn’t matter. Hotter sparge water does not extract more sugar.