Tannins & pH in Batch Sparging?

[Burgs]

I spent the winter doing smaller BIAB brews, but am getting ready to break out the cooler MLT and do some 5 gallon all grain brews again.

This has me thinking about tweaks and improvements to my process, and one thing that I've been considering is no sparge.

This article in particular had my interest piqued about a few things: http://***********/stories/techniques/article/indices/9-all-grain-brewing/1407-skip-the-sparge

My old way of doing things was to single batch sparge. So, if I were to use the method BYO suggests, my only changes would be to:

1. increase my grain used to compensate for efficiency
2. add my batch sparge water right before recirculating & then drain it all together

Now, first off - I don't want to turn this into batch sparge vs. fly sparge vs. no sparge. I'm also not terribly concerned with efficiency.

What I am interested in, though, are their claims that their method produces a more pH-stable and robust wort. How much validity do you guys think there is to this?

I can't say I've really picked up tannic or astringent tastes in my batch sparged beers. However, I also read about how when you drain the grain bed completely, and leave it exposed to oxygen, that you get the greyish "dough" that forms from crosslinking proteins or some madness like that - and I have definitely had the sandy/doughy grain beds.

I have a 10 gallon MLT, so for smaller to medium gravity batches, I can afford to do this and take up more mash volume in my tun. But, is the whole pH-stable & more robust wort claim really worth pursuing, or is it B.S.?

Thanks!

 

[Homercidal]

Theory states that a high pH water above a certain temp can extract tannins from the husk material.

During the mash, there is generally enough acid from the grain to keep the pH in a reasonable level (as far as tannins go) and the temp is generally low enough to boot (except in the case of decoction mashing where part of it is boiled).

However, during the sparge, the acids are washing out of the mash and the pH rises. Since theory states that it's a combination of pH AND temp that causes tannin extraction, people are advised to keep the temp below 170F during the sparge.

An alternative to this is to treat alkaline water ahead of time to prevent the pH from rising enough to make it a concern.

I don't have it handy, but there are chemical reactions quoted that give credence to these theories. It's not just speculation.

Then again, supposedly HSA has scientific backing and that's pretty much not a problem in practice.

Practical experience seems to indicate that although it's a more expensive option, doing a no-sparge brew makes a better tasting beer. I'd have to advise giving a try a few times yourself in order for you to know for sure.

This also gives you a great chance to collect a second runnings that you can also brew separately to see if you can notice any astringency in. It's likely to be much more noticeable since the amount of tannins present would be, comparably speaking, much higher.

 

[Burgs]

When I batch sparged before, I generally shot for 168F as my grain bed temp - I've never played with water treatments, however.

I've been reading no sparge threads on HBT for a while now, but had always assumed that everyone was just mashing with the full volume of water for the full 60 minutes - so you'd have a really thin mash going on for the full rest, then drain it all.

Re-reading this article was the first time I realized that you could just mash regularly and then use your batch sparge volume as an infusion right at the end to bring everything up to 168-170, then drain the full volume. I kind of like that idea.