Costco is beloved for its bulk-sized items—from almond croissant pastries to viral ice cream sandwiches. But perhaps one of the warehouse chain's most beloved products is its muffins—or at least, they used to be.

Back in December 2024, Costco riled up its customers by making a major change to its muffins. Those giant, fluffy muffins available in mix & match 12-count packs for just $9.99 suddenly morphed into a smaller 8-pack featuring only one muffin flavor for $6.99. But the number of muffins wasn't the only thing that shrank in size. The muffins themselves went from giant to regular-sized. Customers were quick to express their disappointment in the change, writing on Reddit, "I'm shocked they changed muffins up...since it’s something they’re pretty well known for. Won’t be buying these again."

And it seems as though not much has changed over the past six months. Delish got its hands on three different flavors of the new and not-so-improved muffins, and we could totally see where all the customer complaints were coming from. While the lemon raspberry muffins boasted great flavor, the dryness overpowered it and left me (and other staffers) disappointed. They were sadly underwhelming and didn't remotely resemble the gargantuan Costco muffins of the past.

In fact, there's an entire Reddit thread dedicated to the downfall of said muffins. "In a word, will NEVER buy these again, EVER. They suck beyond belief and i'm shocked that Costco ever put out such c**p," commented one customer.

"I’m not renewing my Costco membership over this. The larger muffins have been a flagship product in Costco for years. They have shot themselves in the foot," shared another.

Delish reached out to Costco for comment, but as of this writing, has not heard back.

According to another Reddit thread, employees blame some of the changes on the new CEO, Ron Vachris, who took the reins in January 2024. "It’s been downhill since the new ceo started. Ask anyone who works there," wrote one person. In reply, a 24-year executive Costco member wrote, "I hear your exact comments from Costco employees every time I visit warehouses and engage with employees...Longest tenured employees long gone I’m told plus majority of employee name tags I see have 2024 as employment start year."

A lot of customers are also equating the change in the muffins to shrinkflation, a phenomenon happening across the country at many restaurants and grocery stores.

Professor Toni Farmer, who teaches a class on sustainable agriculture at the University of Pennsylvania, tells me another reason Costco might be shrinking (and changing) its muffins. "In short, massive drought in Peru impacted the blueberry harvest last year," she shares. As a result, Costco is probably "making the muffins smaller and replacing the blueberries with a blueberry flavored cream cheese."

And Costco isn't the only company switching things up. Many big businesses are doing things differently due to both climate change and tariffs. "I believe this is foreshadowing of things to come," Farmer continues. "Companies will be looking at ways to shore up supply chains and ways to work around ingredients that have gotten scarce. Chocolate and coffee are both in danger due to climate change, and many other ingredients will be more expensive if the tariffs remain." No more chocolate or coffee? Now that's a scary thought.