Ever since Berkshire Hathaway (NYSE:BRK-A) (NYSE:BRK-B) Chairman Warren Buffett announced that he took a large stake in Kraft Foods (NYSE:KFT) last spring, investors have been wondering whether the stock was ready to take off. It hasn't happened yet, but Kraft's second-quarter earnings release suggest that that the time may be drawing near.

The numbers look impressive. Organic revenue grew 6.9%. Meanwhile, currency adjustments added 5.6% to revenue, and net acquisitions tacked on an additional 8.9%, for a total revenue increase of 21.4%.

Operating income, excluding unusual items, grew at an even higher 27.6% rate. For the first time in many years, all business segments reported operating-income gains. Consolidated North American business advanced 11.5%, and international units soared by 54.2%.

Case volume declined 1%, but that was the result of aggressive price increases that Kraft has undertaken to offset rising commodity costs, which have restrained earnings growth at Kimberly-Clark (NYSE:KMB), Unilever (NYSE:UL), and a host of other consumer-product companies. I would have preferred to see case volume no worse than flat. After all, sales momentum is all about selling more products.

But in a rapidly increasing cost environment, it's a delicate balancing act to decide how much of a price increase is too much. Kraft management seemed cautious early this year, but it now looks to be passing costs through, to see what the market will bear, and giving up on unprofitable volume. In any event, a 1% falloff in case volume doesn't appear drastic during recessionary times -- at least not yet.

Investors cheered the results, driving the stock 5% higher on a day when the broad market indexes were down about 2%. It helped that the company raised its full-year organic revenue growth target from 5% to 6% and its earnings-per-share target by $0.02 to $1.92.

Even with yesterday's gain, the stock is trading just less than $31 per share. Buffett's annual report disclosed that he accumulated his holding at an average price of $33.38 -- and he has also collected a tasty 3.7% dividend this past year. By my calculations, the current situation leaves Foolish investors with the opportunity to buy into a major Buffett holding at a lower price than the master himself paid. I rest my case.

For related Foolishness: