One of Warren Buffett's worst investments just took another big hit

Warren Buffett just took another big hit on his investment in Kraft Heinz.

Shares of the food and beverage company plunged by more than 15% early Thursday -- and are now down more than 30% this year -- after second-quarter results showed $1.22 billion of new writedowns and the first half of net income that was half of what it was a year ago.

The sell-off erased more than $1 billion worth of Berkshire's Kraft Heinz holding, which amounts to 325 million shares, or 26.7% of the company. In 2015, Buffett's Berkshire Hathaway and 3G Capital joined forces to combine Kraft Foods and H.J. Heinz. Berkshire purchased Heinz in 2013.

Thursday's writedowns -- which included a $744 milion charge off to the value of its Eastern emerging marketsBrazilian, U.S. refrigerated and Latin America exports businesses and $474 hit to the value its Miracle Whip, Velveeta, Lunchables, Maxwell House, Philadelphia, and Cool Whip brands -- bring the total size of the company's charge-offs this year to nearly $17 billion. In February, Kraft Heinz took a $15.4 billion charge as the U.S. Securities and Exchange commission disclosed an investigation into its accounting practices.

Kraft Heinz's struggles have meant problems for Berkshire as well, with the conglomerate announcing a $3.02 billion writedown which Buffett said was "almost entirely attributable" to its stake in the food company. That ultimately led to Buffett telling FOX Business’ Liz Claman that Berkshire "paid too much for Kraft.”

Last month, Miguel Patricio took over as Kraft Heinz CEO with the hopes of righting the ship.

“The level of decline we experienced in the first half of this year is nothing we should find acceptable moving forward," Kraft Heinz CEO Miguel Patricio said in Thursday's release.


"We have significant work ahead of us to set our strategic priorities and change the trajectory of our business. But in my short time with the company, I have developed a strong appreciation for the affinity consumers around the world continue to have for our brands, the talent, and determination of our employees, as well as the commitment of our customers."