"I then split it with some other staff members who didn't have one," she admitted. "We have a small bubble and I felt guilty having one, so we rationed the coffee."
And while the radio hosts joked that it was "so socialist" of her, Ardern went on to say "the saddest thing for them is that I drink half-strength coffee!"
Turns out the PM doesn't go hard and early on the caffeine, even after a level 4 lockdown.
"But after no one having coffee for that long, they needed to take it easy. You don't want to go too heavy, too hard."
Last year when the first level 4 lockdown lifted, Ardern revealed what she'd been craving the most during lockdown.
"Weirdly, I don't drink a lot of coffee and yet I still remember when we moved the ability to go and get a takeout coffee, that felt like a real landmark moment for me," she told The Hits' Laura McGoldrick.
"If not coffee, what does keep you going?" asked the radio host.
"Well my day doesn't start as early as a breakfast radio host but it's often dark at both ends of my day. I drink tea like it's water, I drink a lot of tea."
"Very English, milky. I drink a lot of milky tea just like my grandmother.
"Clearly in this interview you've deduced that I was born old."