Briess extract will ferment just fine. The one thing you need to know when using it is that the sodium in their extract is really high at 160-170 ppm when reconstituted with distilled or RO water, so use distilled or RO and DON'T ADD ANY MORE SODIUM. This is because the water they use to make the extract is really crappy, from Chilton, Wisconsin, known to have high sodium and hardness, and I think can lead to additional "extract twang" from this particular product when used with spring water or other hard water rather than soft/distilled/RO. References:
http://www.thebrewingnetwork.com/forum/viewtopic.php?p=154844
http://www.beeradvocate.com/communi...iess-dme-mineral-profile.664153/#post-7426204
Fun fact (though pretty much irrelevant): I live 7 miles northeast of the Briess
malting plant in Manitowoc (not their
extract plant, which is almost an hour west of here in Chilton), and two of the lead engineers from Briess are in my local homebrew club the Manty Malters. I always wonder whether they've seen any of my online posts about their extract, I haven't asked and don't want to.