I just ran across this article, and didn't see it shared here
Great Commercial Beer from Malt Extract
by Donald R. Outterson
Extract brewing, the step child of the brewing family, can produce top-quality brewpub and microbrewery beers. The key is understanding the properties of malt extracts and working with them.
I have had the unique experience of professionally brewing a wide variety of beers using many different methods, from cask-conditioned English ales using single-temperature infusion to Reinheitsgebot lager beers using upward infusion, and including work in malt extract brewpubs using ale, wheat, and lager yeasts. I also worked at a malt extract brewpub in Australia with limited access to supplies.
The most difficult of these formats to master was the malt extract lager brewpub. In going from full mash brewing to extract brewing, the brewer loses a degree of control over wort quality. The process is rebrewing as much as it is brewing. For this and other reasons, many avoid and even look down on extract brewing. Malt extracts, however, can produce great beers if the brewer understands the peculiarities of malt extract and how to work with it.
This article provides some simple tips for successfully brewing with malt extract. Although the context is commercial extract brewing, the practical issues are equally relevant to home brewers.
Read the rest of the article here: http://brewingtechniques.com/library/backissues/issue1.4/outterson.html