BIAB to Three Tier??

[NormPeterson]

I have used the BIAB, Brew in a bag, method for over 6 months now. I have been seeing a lot of three tier systems and am wondering what the ups are vs. BIAB, and the exact process carried out in each vessel (even without BIAB I thought there was no need for anything other than a cooler for mashing) used in a 3 tier system. I see simple 3 tier systems to elaborate 3 tier systems. It would be helpful to understand WHY/WHAT separates these other than cost.

 

[Ridire]

First the caveat: I have never brewed with a mash tun, so do not consider me an expert. With that said, my take on this:

Purpose of each vessel in a 3 tier system-

1) hot liquor tun - this is merely a place to heat water to add to the mash and to use for sparging.

2) mash tun - used to extract fermentables from the grains (the cooler you reference)

3) boil kettle - used to boil the wort

The benefit to the 3 tier system over the BIAB? I'm sure some will disagree with me but the only benefit I can understand is the ability to brew bigger beers or more volume of beer. With BIAB, your grain bill is somewhat limited by the need to lift the bag, and to fit the grains in the bag. A mash tun can handle a lot more grain without breaking your back or requiring a significantly larger boil kettle.

But for me, it is no problem to brew 5 gallon batches with normal to moderately high ABV using BIAB, so I'm content with that method for now.