Dunk sparge advice needed

[Greynolds16]

Hey everyone - I am thinking of moving up my volume from 2.5 gallon all grain BIAB to making 5 gallon batches. My issue is that I have an 8 gallon kettle, which rules out doing a straight up 5 gallon BIAB because there isn’t enough space. I am waiting to pull the trigger on a mash tun eventually but wanted to try a dunk sparge as a route to get to my 6.5ish gallon preboil.
How much water should go in the mash and how much should be reserved for the dunk sparge to get to 5 gal?

 

[IslandLizard]

You can mash with any amount of water that will fit your kettle, while leaving at least 2 inches of headspace so you can comfortably stir it, without splashing too much.
There are calculators for that. I think the one at Priceless Brewing is highly rated.

When the mash is done, lift the bag out, and drop it into a bucket to dunk sparge it.
Dunk sparge once or twice (twice gives better efficiency).

Total sparge water volume = your calculated preboil volume (your estimated 6.5-ish gallons) - the volume in your kettle after lifting the bag, letting it drip, and squeezed it.

If you do 2 sparges, cut your total sparge water in half for each sparge, using 2 equal volumes (again, for best efficiency).

You could preheat your sparge water and store it, such as in an (old) insulated Gott, while mashing. Many claim sparging with cold or lukewarm water works just as well. I've never tested that premise.

Make sure to treat all your brewing water with a pinch of Campden to remove any chlorine or chloramines, if present (e.g. all municipal water), before mashing, sparging, or using it in beer, otherwise.

 

[bracconiere]

i'd treat it like a batch sparge and dunk in something like this...$20 bucks....

https://www.uline.com/Product/Detai...uXZ0F1DPCR2un5rQ5zxoC1IIQAvD_BwE&gclsrc=aw.ds
i've heard temp doesn't matter that much for sparge water....so just throw the bag in, run the hose over it....pull it out, then dump the wort it in the kettle!


edit: some people question my brewing skills though.... but i'm serious, that's what i'd do....either that or get a cheap barb i could fit in the bottom of the can, then drop the bag in on a chair higher then the kettle, and just sparge it till the kettle was full......could use a hose shut off instead of a ball valve to slow it down....cheaper still!