Sparging a Small Beer

I am looking to do a 5 gallon batch of Berliner Weiße that should clock in at 1.028 OG - all grain, batch sparge; no boil.

Grist is 2.5# German Pilsner and 2.5# German Wheat Malt; mash hopping with an ounce of Tettnanger; mashing in w/ 6.5 quarts at 133 x 60 minutes, then raising to 151 by decoction, and mash-out at 170.

On my system, I would expect to get about 1 gallon of first runnings, so would be batch sparging a total of 4 gallons.

Should I be worried about tannin extraction with that large a volume on a small mash? Would acidifying the sparge water give a bit of a buffer if I’m bordering on oversparging? With that small a grain bill/low an OG, I am assuming the batch sparge may be south of 1.010.

I’ve never done precisely what you are describing, so my info could be off, but one of the advantages you typically get from batch sparging is you don’t need to worry about tannin extraction. Because you are not slowly changing the water profile and rinsing out the buffering capacity along with the sugars, there is no slow increase in pH that would cause tannin extraction.

I agree with the assessment above. Why do you plan to only have first runnings of 1gal though? With this grist you could do no sparge if your tun is big enough.