Last month, officials in Georgia said they were indefinitely suspending executions so they could test a drug they had intended to use in a lethal injection.

That drug had “appeared cloudy” shortly before the execution was set to occur, so they halted the process and said they wouldn’t try to carry out any other executions until they figured out what happened with the drugs.

Well, six weeks later, we seem to have an answer: The drugs were too cold.

The Georgia Department of Corrections said Thursday that pharmaceutical experts the state had asked to check out the execution drugs determined that they “had precipitated,” probably because they were transported and stored in cold conditions.

Drug samples were sent to a lab in Indiana, which found no evidence that the drugs had become adulterated, according to an affidavit from Jason Zastre, an associate professor at the University of Georgia’s College of Pharmacy.

“In this case, the most likely cause of the precipitation observed within the solution was that the solution was shipped and stored at a temperature which was too low,” Zastre wrote.

Georgia had intended to use a fatal dose of pentobarbital, a sedative, to execute Kelly Gissendaner on March 2. However, several hours after the execution was scheduled to occur, the state called it off when authorities saw that the drugs appeared to be cloudy. (This was the second time in less than a week that Gissendaner’s execution was postponed; five days earlier, the state had called off her execution because of a looming winter storm.) The following day, executions were indefinitely suspended.

Officials say they will follow the recommendations of experts who advised them how to make it less likely that the pentobarbital will precipitate in the future.

Georgia’s problems with the lethal injection drugs come as an ongoing shortage of these drugs has caused states across the country to scramble. Even in Texas, the country’s most active death-penalty state, authorities only recently found enough pentobarbital for it to carry out some of its planned lethal injections.

[Why the U.S. won’t stop executing inmates even as a Supreme Court ruling looms]

States have altered their execution protocols because of this shortage, which has created a patchwork system in which lethal injections vary widely from state to state. The U.S. Supreme Court will hear an argument over one of these new lethal injection protocols later this month.

It is unclear when Georgia hopes to resume executions. Last month, it had said that sentencing courts would issue new execution orders when the state “is prepared to proceed.”

A spokeswoman for the Georgia Department of Corrections did not immediately respond to a message seeking comment.

Related: Why the Supreme Court is considering lethal injection again