BIAB Mashing steps - full volume, steps?

I think I am going to try to do a hefeweizen as my first all-grain BIAB beer. I am wondering what opinions there are on the different approaches for mashing? Multi-rest infusion? Full volume in-kettle steps where the burners are turned on to increase heat as needed. Or there is the Decoction method, which I am still a little fuzzy on. I have a 16 gallon pot I am working with, so I have plenty of options for my 5 gallon BIAB setup. I am just curious what the opinions and thoughts were from those more experienced with these procedures. I have read that different beer styles also lend themselves to certain methods over others, but I haven't really read which ones do best under which methods. I appreciate the feedback.

There is a wealth of knowledge in the biab sticky that is really informative and an enjoyable read too. I over-shoot my mash temp in a 10 gallon kettle by 3-4 degrees, mash in and usually end up right on tempurature. As far as mashout, I have a screen that fits my vessel to keep the bag from getting "direct heat" from the burner. The bag rests a couple of inches from the bottom of the kettle. Heat to mashout temp and stir constantly during the process. I end up in the 70-80% efficiency range normally.

We start with 5 gallon mash and add boiling water to bring it to the next step. We pull the grains out at the last step and boil them for the decoction step. We generally use 8 gallons of water to make a 5.5 gallon batch. Just took 1st with my BIB Kolsh, multistep infusion with 1 decoctation step.

I like BIAB for its simplicity. That said, I do full volume, one rest, no mashout. Quick and easy. Just the way I like it.

BIAB (the original full-volume version) is really designed for a single infusion, but if you want to add a batch sparge, you could do step mashing with boiling water or a decoction if you really wanted to. I don't see the need.

You need a separate vessel with some kind of heating to be able to do the decoction properly. And you have to watch it like a hawk and stir constantly or you'll end up with stuck burnt grains on whatever pot you use for that.

Decoctions are not difficult, but you do need some extra equipment and they take a little more time to perform than your typical single-infusion mash.


There has been a lot of discussion over the relative merits of performing decoctions vs. adding some melanoiden malt to the grist. Denny Conn did an experiment where the results were somewhat indeterminate as to whether decoction helped or hindered the beer, with several different styles and both qualitative and quantitative analysis on the results. There's another brewer here on HBT who did a more recent set of experiments that I think indicated a bias towards doing the melanoiden substitution instead of decoction, and I want to say that Jamil Zainesheff did a similar experiment with indeterminate results as well.