Brewing Low Gravity All grain 10 gallon batches ... ?

[EagleDude]

I generally brew nothing under a 1.050, but just recently brewed a 11 gallon 1.032 berlinerweisse currently fermenting. At the start of it all, was was concerned about fly sparging 10 gallons + of wort through such a shallow grain bed (12 lbs of grain). Specifically, I was worried about hitting extraction gravities dropping below 1.010 and/or PH (which I dont have a monitor for). I brewed the batch despite these concerns and sure enough I hit my numbers as expected, but the final run-off was down to 1.007 (damn it!).

This is an issue I usually never have to worry about since I artificially set my mash efficiency ~4% lower than I actually acheive. By doing this, I collect all my sugars by the time I reach 10 gallons of wort collected then top off with extra filtered water to reach the desired ~13.5 gallon pre-boil volume. Sure I'm waisting a little bit of grain, but never have to add DME. If the conversion/sparge is less efficient than usual, I just keep sparging to full boil volume. Sparge gravity usually never gets below 1.020 or 1.015.

My thoughts on the low gravity brew would be to calculate the recipe for a 5.5 gallon 1.064 brew (ends up being the same amount of grain), collect the 5.5 gallons and then dilute down to the full 11+ gallon batch volume prior to boil. I know the system won't have an issue with sparge gravity dropping below the 1.010 gravity at the 5.5 gallon 1.064 gravity level.

The real question is what reasons should I not brew any future low gravity beers as described above or if the theory is fine and I should proceed with no worries.

Thanks,

[spiderwrangler]

Unless you have have a philosophical objection, or your system doesn't handle them well, a batch sparge will help avoid oversparging...

[BrewerJ]

I think you are worrying a bit too much about oversparge. As long as your sparge water doesn't have to high of ph i don't think you will notice any astrigent characters. Secondly if you want to do the 5.5 gallon sparge and then top up with water that will work just fine too.

[brewinhard]

To avoid any possible issues with astringency from over-extraction, you could always run a no-sparge mash, then top off with water to hit your boil amounts.

[grod]

To avoid any possible issues with astringency from over-extraction, you could always run a no-sparge mash, then top off with water to hit your boil amounts.

...or just batch sparge.

love

g

[spiderwrangler]

+1 to the grod

[Stinkfist]

Yeah I would do the no sparge method...

[EagleDude]

I definately prefer the fly sparge method since it gives you much closer control of your Original Gravity making it possible to hit your target gravities/volumes easily. I am thinking that collecting the 5 gallons of 1.064 wort then diluting down to the 10 gallons of 1.032 wort would be my best option ... plus would save on time spent sparging. I guess the main concern would be if adding the 6+ gallons to dilute would screw up the pH? No pH meter here so I won't know if that is a real issue.