BIAB and the reduction of tannins

[Silver_Is_Money]

It seems to me that no sparge BIAB will alleviate concerns with regard to picking up tannin's or other off flavors that may occur during the sparge step. Have others who have made this transition noticed this to be a benefit?

 

[Jayjay1976]

I biab with full volume and use a pump to recirculate throughout the mash, never had any tannic flavor and I use a very fine crush. In my mind, introducing fresh, 1.000 gravity sparge water to a bed of grain already depleted of most of its sugars is setting up perfect conditions for extraction of unwanted compounds, including tannins. I'm not a chemist, but mashing with full volume means that as extraction progresses, the gravity of the wort steadily increases until the extraction "pressure" it puts on the grain bed is practically zero. To leave the bad stuff behind, get yourself a Wilser bag, mash full volume, and don't look back. Oh, and resist the urge to squeeze the bag, just let it hang over the kettle.

 

[kh54s10]

From what I have read about extracting tannins it is quite unlikely in a homebrewing setting. You need a combination of pH and temperature that you should never see. If you are getting tannins with any system you are doing something wrong.

 

[Foosier]

I agree with KH54s10. Tannin extraction is a function of temperature and PH. If we are monitoring temperature and PH the way we should during the mash the chances of extracting tannins are extremely low if not impossible. BUT... If you are not paying attention to mash PH and you are careless with mash temp, mash conditions can exist which will start tannin extraction. I believe you need a temp over 170 and a PH higher than 5.8 (I think that is the number?) to risk tannin extraction.

Since most experienced brewers understand the value of managing PH and temperature and take steps to do so, this is not usually an issue. It is a bigger issue for new brewers who do not understand the key variables to control.

 

[wepeeler]

I too do full volume BIAB. Double crush fine, no sparge. Never had off flavors. Seems to be some who squeeze and some who let gravity do it's thing. Personally, I squeeze the bag like it owes me money (actually, I pay for the grains/sugar, so it does!), and I've never had issues.