If you were planning to serve whipped cream with your holiday desserts this year, you might want to acquaint yourself with the homemade kind. Thanks to a nationwide shortage of nitrous oxide, a critical ingredient in aerosol whipped creams, some major manufacturers have announced that they won't be able to keep up with holiday demand. Among the companies that expect to see shortfalls are ConAgra, which makes bestselling whipped cream Reddi-wip, and Dean Foods, which sells whipped creams under a range of local brands. But the impact of the shortage will likely be more widespread than that, experts say.

The story behind the whipped cream shortage — which involves laughing gas, a tragic explosion and a federal investigation — reveals one of the industrial food system's core weaknesses: the increasing concentration of power among a few companies, in a few areas and at a handful of plants.

"It's very concerning how vulnerable we're making our food system to weather, fuel shortages, accidents, strikes, foodborne illnesses," said Philip Howard, a sociologist at Michigan State University who studies consolidation in the food system. "There are many variables that make it possible that the food on our grocery shelves this week won't be there the week after."

A key ingredient in whipped cream is nitrous oxide, sometimes called "laughing gas" for its ability to relax people and ease the pain of tooth extractions. But it also acts as a propellant to get whipped cream out of the can and a preservative to keep it from going rancid.

Just two companies, Air Liquide and Matheson Tri-Gas, produce nitrous oxide for all of the United States and Canada. Together, they operate five nitrous oxide plants, which supply the three packing facilities that can the majority of America's whipped creams.

At each of these highly consolidated nodes, even a small disruption could impact a large number of products further down the supply chain.

"This story is a metaphor for the vulnerability of the entire food system," said Daniel Block, a professor at Chicago State University who has studied the geography of food distribution. "It serves as a sort of canary in a coal mine, in the case that was a real industrial disaster."

On Aug. 28, the Air Liquide nitrous oxide facility in the Florida Panhandle town of Cantonment — operated by its subsidiary Airgas — suffered an explosion that left one man dead. The incident, which is still under federal investigation, reduced the company's nitrous oxide output in "the short term," spokeswoman Sarah Boxler said — though she did not give a specific timeline and said that the explosion handicapped the facility "indefinitely."

Air Liquide has allocated its remaining supply to medical clients first and back-burnered its clients in food manufacturing. With a limited supply of nitrous oxide, ConAgra and Dean Foods said they had to slash their whipped cream production, leaving peppermint hot chocolates and gingerbread cakes naked in the midst of the holiday season.

"We are proactively managing the production of Reddi-wip, and are doing the best we can to make it available to as many consumers as possible," said Lanie Friedman, a spokeswoman for ConAgra. "We should have our full supply up and running by February."

Neither Kraft, which makes Cool Whip, nor Saputo, which sells whipped cream under the Land O'Lakes label, responded to questions about whether they, too, would see shortages. But because most aerosol whipped cream brands are made at the same large packing facilities, it's likely that a shortage that impacts one label impacts all of them.

"The nitrous oxide shortage has impacted the majority of food suppliers who distribute aerosol products," said Reace Smith, a spokesperson for Dean Foods. "Our co-packer is working closely with suppliers and allocating the supply based on greatest need."

Manufacturers say the shortages will strike consumers on a store-by-store basis, depending on demand and pre-existing inventory. Dairy cases from Boston to Omaha, Neb., have already gone empty.

Right now, Smith added, restaurants, hospitals and schools — not grocery stores — are taking priority.

And yet, even after Reddi-wip is back in stores, the core problem will remain: the concentration of food production among a few companies, in a few areas, and at a handful of facilities.

For instance, dairy farms — which supply the cream in whipped cream — are growing larger and less numerous, as are the dairy cooperatives that distribute their product. The number of dairy manufacturing plants fell by 75 percent from 1970 to 2005, according to the Department of Agriculture.

Howard said they see a close parallel in the Eggo waffle shortage of 2009, which deprived consumers of the frozen breakfast food for several months. Kellogg's, which makes Eggo, eventually revealed the cause was a flood in one manufacturing facility, and the outbreak of listeria in another — problems that would have had a less dramatic impact, Howard argues, if Kellogg's had a less concentrated production process.

"If there is a problem at a single facility, there's a big impact," said Paul Wolfe, a policy specialist at the National Sustainable Agriculture Coalition, which advocates on behalf of midsize farmers. He calls the whipped cream shortage a "symptom of the consolidation taking place" everywhere from pork slaughterhouses to California pear orchards.

Reversing the trend will not be easy, Wolfe acknowledged. The NSAC has lobbied for more antitrust enforcement in the agricultural sector, particularly in chicken and livestock processing, where the market is dominated almost entirely by four large firms.

Howard said he would also like to see regulators reduce subsidies for large companies and do more to empower competition from small producers.

He points to craft beer as one industry where such initiatives have worked. Despite the mergers of large beer companies like Anheuser-Busch InBev and SABMiller, small and independent breweries have flourished, benefiting from federal and local tax incentives that target smaller operations. The number of breweries in the country reached a record-high 5,005 this year, according to the Brewers Association.

In the meantime, consumers will still be able to get whipped cream this season, if they're willing to compromise or look around. Brands that have already built up their inventory will be spared, for instance, such as Natural by Nature, an organic brand sold along the East Coast. There will also be no impact on nonaerosol whipped cream products, such as Cool Whip tubs.

The best solution, however, might be whipping your own — because there's no nitrous oxide required.