Why is the COVID-19 pandemic causing a ketchup shortage?

PHILADELPHIA -- The COVID-19 pandemic has caused a shortage of one of America's favorite condiments: ketchup.

Restaurants have relied heavily on takeout orders to survive during the pandemic, which has caused a need for more ketchup packets.

But once those started running low, some eateries began pouring out bulk ketchup into individual cups.

The Wall Street Journal reports that low inventory of ketchup is hitting mom-and-pop restaurants as well as chains like Texas Roadhouse.

SEE ALSO: Consumer alert: Manufacturers warn of price increase for house hold staple

Diapers, paper products, cereal and pet food are set to increase in price as companies pay higher freight, manufacturing, shipping fees and products for ingredients due to the pandemic.

According to the restaurant-business platform "Plate IQ," the ketchup shortage has caused packet prices to rise 13% since January 2020.

USA Today reports that Heinz is working to increase its supplies in order to produce 12 billion packets a year.

-- CNN contributed to this report.