What happened

Packaged foods specialist J.M. Smucker (SJM 3.29%) shed 14% last month, according to data provided by S&P Global Market Intelligence.

The decline pushed the stock to lows that shareholders haven't seen since early 2015.

SJM Chart

SJM data by YCharts.

So what

Nearly all of the August slump came immediately following Smucker's fiscal first-quarter earnings report that was issued late in the month. In that announcement, the company posted a 4% drop in sales as operating income dove by 20%. The results fell short of executives' projections, mainly thanks to market share losses within the Folgers coffee franchise.

A grouping of popular Smuckers products, including Crisco oil and Jif peanut butter.

Image source: Smucker.

Weakness in that brand helped drive sales down 6% in Smucker's coffee division. The company also endured weaker volume in its consumer food segment, especially in the Crisco, Smucker's, and Pillsbury brands.

Now what

CEO Mark Smucker and his executive team now see full-year sales dropping slightly, as opposed to the 1% increase they had originally forecast in early June. They're optimistic that they've made the right pricing and promotion changes to shore up market share in the Folgers brand, though, and so investors will be looking for healthier sales growth in the coffee division over the next few quarters.

Over the long term, Smucker's results will depend on its success at innovating within its portfolio of food franchises while adapting to quickly shifting consumer tastes around packaged snacks.