HONOLULU (KHON2) — Some local shave ice spots have been running out of the tasty treat by the afternoon.

The owner of Shimazu Shave Ice told KHON2 that he has no choice but to close up shop on some days.

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“Well, last week Wednesday I think we closed around 3 o’clock because it just ran out,” said owner Kendall Shimazu. “If anybody else comes in, I’ll just kind of shout, ‘Sorry, out of ice!’ Most people understand, some people they’re like, ‘What?'”

Some might think that it should not be hard to make ice — just freeze water! It is not that simple for shave ice stores, however.

Block ice — which is then shaved down — has a bit of science behind it.

“It’s more dense, less air in it,” Shimazu said. “If we try to freeze it on our own, it might melt too quickly or it might shatter right in the middle of us making it.”

Shimazu Shave Ice does not make its own block ice, but Uncle Clay’s House of Pure Aloha (HOPA) does.

Sky Yamamoto, HOPA’s product manager, told KHON2 that they simply would not be able to keep up with demand without their own supply.

“Just the demand within the last two years for our shave ice has gone up considerably,” Yamamoto said. “We make our own ice here pretty much every day, like we try to refill our own tubs, you know, just Tupperware things.”

HOPA posts on social media when they expect to run out. They had to do just that on Friday, July 1.

“We’re always worrying, like, can we make it through the day,” Yamamoto said. “Are we going to have to sell ice cream for the rest of the day? We tell the customers the same thing pretty much every day, we’re like, ‘we apologize.'”

Hawaiian Ice Company said their main product is cubed ice in bags. They do sell blocks, but not enough for the entire island of Oahu.

Mike Wildberger the owner of Kihei Ice Company on Maui said manufacturing blocks professionally comes with the same patience as doing it in-store.

“It’s a solid 24 hours and if you don’t get it out by 48 then the block might be cracked and not usable,” Wildberger said. “So, you have a window when it’s frozen, but not too frozen.”

Shave ice shops are used to busy summers and told KHON2 that they are not going anywhere.

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“And summertime there’s always going to be a shortage of ice, that’s just how it is. So, you know, just serving what we can with a smile,” Yamamoto said.