Brew In A Bag - Resource

The Brew in a Bag (BIAB) method of all-grain brewing has gained a lot of popularity in the past years.  The basic concept is that BIAB uses a brew kettle as a mash tun, a hot liquor tank, and a kettle all in one.  It is a one-vessel brewing system.  The kettle is filled with all of the brewing liquor (the infusion water and the sparge water), which is heated to temperature a couple of degrees above the sacchrification rest temperature.  A mesh bag that is approximately the size of the kettle is placed in the water and the milled grain is stirred within that bag and left to sit for an hour or until conversion is complete.  The bag is then lifted out of the water and and the bag is allowed to drain into the kettle as it heats to the boil.  The rest of the process is the same as any other all-grain brewing system.  Lug Wrench first reported on BIAB a year ago.

Brad Smith, host of the BeerSmith podcast, recently interviewed Patrick Hollingdale, an early proponent of the BIAB process.  Patrick provided some history on the BIAB method and described it in great detail.  BIAB was first developed and promoted in the Austrialian homebrewing community as a method to get people into all-grain brewing at a lower cost.  BIAB only requires a large kettle, burner, and the mesh bag.  It eliminates the mash and sparge vessel, thus saving the brewer money.  As BIAB has been adopted by the larger homebrewing community, many of the concerns surrounding it as a brewing method have proven unwarranted.  Some of these concerns included:

• Efficiency: BIAB turns out to be more efficient than batch sparging because the sparge water is actually in contact with the grain for the entire mash time.  BIAB brewers report efficiencies between 70% and 80%.
• Wort Quality:  BIAB wort is usually cloudier than fly sparging wort because there is no recirculation step.  This can result in larger amounts of trub going into the fermenter, but tasting trials have shown no differences in finished beers in triangle taste tests.
• Mash Temperature Drop:  BIAB has a larger thermal mass than other sparging systems because all of the water and grain is in one vessel.  This helps prevent temperature loss and can be augmented by surrounding the kettle with insulation of some sort.

Patrick is an active member of the BIAB online community - BIABrewer.info.  This community provides a lot of free information on BIAB and works to promote this simple, yet efficient method of all-grain brewing.  If you have ever thought of giving BIAB a try, be sure to listen to the BeerSmith interview and take a look at BIABrewer.

Cheers,

TW