We've had some inquiries about this situation, so I wanted to get the full details out to you guys before the patch. I'm still operating without a graphics card here, so I apologize for the low quality images I'm sharing. The important part is the information and hopefully you can overlook the rest :)
On the Test Realm, the Dry Yeast and Hops are both gray items. If you have any of these, you should use or sell them now. They will be worthless after the patch. Here are pictures of them:
As you see these will be vendor trash and have essentially no value. If you can't sell them, at least make them into the Lager before patch day. Speaking of which, here's the new version of the Darkbrew Lager recipe after 4.1 hits:
You can see that this version uses vendor ingredients that any player will be able to purchase in essentially unlimited quantities. I'm not quite sure of the reason for this change but it could be serving as a bridge recipe between Wrath and Cataclysm content. It seems to fill the same skill point gap as the Wrath feasts, at least if we can rely on Wowhead's skill rankings. If I get a chance to test this I will give it a go.
I don't know how many of you have noticed this but MMO-Champion posted a bunch of new Cooking and Fishing dailies on Friday. Once my new graphics card arrives I'll be popping in to test those out for you and get the skinny on how they work!