Jeni's Splendid Ice Creams says it has traced the source of listeria in its Ohio production facility to a spout on its pint-filling machine.
CEO John Lowe says in a statement Wednesday that the company will never be sure how the bacteria got into the machine, which filled a portion of the pints for retail sales. He says efforts continue to clean the Columbus facility.
Lowe says the company estimates it will spend about $200,000 on changes to make sure it doesn't happen again.
Jeni's announced April 23 that it would recall all retail products and close ice cream shops in six states after listeria was discovered in some pints and later in the factory.
The company said it would destroy 265 tons of ice cream worth more than $2.5 million.