Interesting, how can one avoid this? Mashing low and raising to mash temp? Just not sure I understand how one can avoid this and why it is harmful as I believe most here use an infusion method?
After re-reading my post I realize that I may have given the impression that the infusion method makes beer "taste green." It's a "problem" that doesn't need to be solved because it's merely part of the process:
any beer produced under any method will taste green if it is not conditioned adequately. What I meant to say is that the infusion method is suitable if you want to drink an ale fairly quickly after fermentation is over, and that aging an ale, while necessary, is not usually an extended process. By way of analogy: you want to eat a soufflé shortly after it comes out of the oven - but neither while it is scalding nor a couple of hours later when it is cold. Cassoulet, on the other hand, is usually better the next (or even the next) day. It's all about timing: different beers require different aging times, and, as stated above, beer at 6-8 weeks old can be considered "fresh" instead of "aged."
No knock on the infusion method intended; it's not "harmful" at all. It's how I learned to brew British bitter using Marris Otter and Crystal malt. I expect to have a quality beer about 2 months from brew day (e.g., 1-2 weeks for fermentation and six weeks for conditioning). Some people can do it in less time; my experience has been that extending the aging time to 6 weeks and then tasting the beer helps me to find that point where the beer tastes best (to me).
However, the infusion method has some inherent limits that brewers must find ways to get around. The high-modified malts that work well for the method may not drop the pH of the wort sufficiently to favor beta amylase enzymes. Consequently, you need to find a way to drop pH, but not so far as to disfavor alpha amylase; pH 5.4 seems to be an acceptable compromise. Then there is the problem of mashing at the appropriate temperature for both enzymes: alpha favors higher temperatures but beta denatures at 149F. Hence you can, for example, mash-in at a temperature that favors beta, and then do a step mash to a higher temperature that favors alpha, etc. The problem is that you are always looking to find an acceptable mean for both enzymes with respect to pH and temperature; it's like threading a moving needle, and some can do it better than others. Look here for posts about how to do a step mash and also
here.
There are other ways to produce a beer that will age-out well: exploring different yeasts, pitching rates, and fermentation temperatures allows the brewer to produce a beer with esters that create different flavor profiles, and these profiles can develop in a beer in significant ways. See here for an introduction.
See Gordon Strong's
Brewing Better Beer, and Stan Heironymous'
Brew Like a Monk for some excellent discussion about ales.
Lagers, on the other hand, benefit from other mashing methods and an extended aging time. After you've done a few step-mashes, consider decoction method for producing lagers. It solves many of the problems described above, but it is significantly more labor intensive. It's what I've been doing for the past year or so, and I've liked the results - but I consider myself a neophyte here. Look for posts by VladOfTrub on the forum for some in-depth discussion about the method. I'm planning to brew an Altbier this spring and then circle back and see if I can produce a British ale using a similar method.
