BeerBorg

Do any of my fellow biabers brew two beers from one mash? I don't mean by splitting the wort in half but by using what would be called the second runnings in a traditional set up.

I'm wondering if I could brew one high gravity beer and then dunk sparge to get the second lower gravity beer. Does anyone have any experience doing this with a biab process?

I've not done it but I've watched so many YouTube videos and seen it done with the traditional set up. I'm not sure how well you'd work out with the BIAB process but adding some DME would help out.
Seems like many vids I've seen they start with an imperial stout and with the second/third runnings they end up with a low gravity stout. Then you also have the option of using a different yeast and if you want, adding other things such as cocoa nibs, coffee or whatever.

I've done it "back in the old days" when I had a cooler mash tun. Used to brew a huge Belgian use the second runnings for a small Belgian table beer.

But I have not tried it with BIAB, and I'm not sure you could pull it off by just doing a dunk/sparge.

If I was going to try it, what I'd do is do my BIAB, pull the bag, and then put the bag into another pot with fresh strike water, and do a "second mash". Just let it go and see what you get. It might work to make a small beer if you were brewing something big in the first pot. You might want to go with a thinner mash in the second pot.

But that's all just a SWAG.

The good thing is that it costs you nothing but water if it doesn't work, IE check OG of second runnings before you commit to brewing with it.

You might also try letting the bag drain into a second vessel, at least partly. If you do a regular BIAB batch and check the sparged gravity, you would have a basis for calculations.

Braukasper and I are still going through possibilities for the RCE, but are considering using this approach, why is known as partigyle. I would use BIAB for mine, since that's my approach to all-grain. I usually batch sparge, but in this case I would increase the initial grain and use no-sparge, with the sparge being the mash for the second beer. I would also add more specialty grain to the second mash, so it has enough flavor and body. I have had this type of plan in mind for a while, but not done it before, although I have used second runnings from a club brew-day, with additions like this. There is an article in the current BYO that includes partigyle.

Dawg LB Steve and I are thinking of this for our RCE as well. I biab. I never sparge but if I pull the bag and let it drain into a separate kettle and then sparge over the bag it should work. I might have to add extract to up the OG.