I recently bought a few metal shelving units from Menards to give me more vertical space for an ever-increasing batch of canned goods, and let me tell you, having sturdy shelves is making a huge difference. The combined weight of myriad cases of canned goods was becoming a worry for my original storage shelves, but these metal units are up to the task and are a huge help for my pantry organization.
The first photo below is of some of the shelves I'd already had set up, and as you can see I've arranged them at right angles to each other to get the maximum amount of shelf space relative to the floor area available for the shelves. As an example, eight shelf units that are four feet long and one foot deep can be set up at right angles in a long row of connected units so that you could fit those eight units in a 5-by-16-foot area--bolt four shelves together side by side (which would span 16 feet in length) and then bolt each of the remaining shelves perpendicular to the left end of the shelves that are parallel to the wall. (The shelves that are parallel to the wall are a foot deep and the shelves that are perpendicular to those shelves are four feet wide, for a total depth of five feet, and the four 4-foot-long shelves are 16 feet long when bolted together.)
In the second photo, hopefully you can see the depth of the storage area to give you an idea of how much you can potentially stock up in what may look like a small area. Shelves are one of your best friends when it comes to creating space for food storage.
I hope this helps you expand your pantry no matter how small it looks!