1. Diamond Naturals dog food: Confirmed

Websites including Dog Food Insider claim that Kirkland Signature Dog Food is actually manufactured by Diamond Pet Foods, also known as Schell and Kampeter, Inc.
That might not be enough evidence on its own, but in 2012 the Kirkland brand was part of a recall for Diamond dog foods following a salmonella outbreak at Diamond’s production plant in South Carolina. Costco and the Kirkland brand were both named in a class-action lawsuit.
There’s been no word of a break with Diamond following the incident, and the Kirkland brand remains popular with pet lovers.
2. Starbucks coffee: Confirmed

Even coffee snobs may be intrigued by a few of Costco’s relatively inexpensive house blends, which boast of their ties to the world’s largest coffeehouse chain.
Kirkland offers certain varieties of their house blend with the stamp, “Custom roasted by Starbucks.”
The two-and-a-half-pound Starbucks-affiliated bags include Kirkland’s Signature House Blend Medium Roast, Espresso Blend Dark Roast and Decaf House Blend Medium Roast.
3. Perrigo infant formula: Confirmed

While Kirkland Signature’s Infant Formula was once a product of Abbott Laboratories — the makers of Similac — it seems the brand has converted to Perrigo.
A USDA report to Congress on baby formula prices and availability says Abbott Laboratories began producing infant formula for Costco under the storebrand label in 2001.
However, veteran parents have noticed the yellow box of Kirkland’s Signature Infant Formula has since been replaced by a blue box bearing the name Kirkland Pro-Care Infant Formula.
Perrigo’s StoreBrandFormula.com, which catalogues the company’s retail relationships, includes Costco on its list of partners and links directly to the Kirkland Signature Pro-Care Infant Formula on Costco’s website.
4. Jelly Belly candy: Confirmed

It’s in the name.
Kirkland openly teamed up with candy company Jelly Belly to sell their signature “gourmet” jelly beans. At Costco you can get four-pound jars of sugary goodness featuring 49 different flavors that are kosher and fat free.
Assuming an equal distribution of beans, that means you’ll be able to enjoy a full 1.3 ounces of your favorite flavor in every jar.
5. Duracell batteries: Confirmed

Many buyers avoid store-brand batteries for fear they’ll drain faster than the ones produced by the big-name brands. You won’t know until your device drops dead at the most inconvenient time.
Thankfully, Costco’s generic batteries are made by a company that’s “Trusted Everywhere.”
Costco CEO Craig Jelinek revealed that Duracell is the manufacturer of Kirkland Signature Batteries in an interview with Atlanta station WSB-TV in 2016.
6. Grey Goose vodka: Denied

Plenty of people will tell you with confidence that Costo’s vodka is a duplicate of Bacardi’s Grey Goose, produced in France. And the now-defunct alcohol research site Under the Label reported that both vodkas are made using water from the Gensac Springs in the Cognac region.
However, the global ambassador for Grey Goose denied the rumor in an interview with Business Insider, and Costco representatives have never commented.
Don’t be too disappointed, though. Kirkland Signature Vodka has trounced the expensive name brand in multiple blind taste tests despite being a fraction of the price.
7. Bumble Bee tuna: Confirmed

Next time you’re hankering for some white albacore, don’t worry about sacrificing quality for cost.
In a 2003 interview with Money magazine, Costco executive vice-president Tim Rose argued that the canned tuna available on the market had declined in quality for years. So Costo struck a deal with global seafood company Bumble Bee to make a meatier product, just “like it used to be.”
The new “superior quality” solid white albacore hit shelves in 2002.
8. Formaggi Zanetti Parmigiano Reggiano: Confirmed

Unlike the “Parmesan” you sprinkle out of a can, the name Parmigiano Reggiano can only be applied to hard cheeses made in certain regions of Italy and subject to strict standards.
Anyone trying to pass off their product as the genuine article can expect a visit from the Consorzio del Formaggio Parmigiano-Reggiano.
The back of Kirkland’s parm shows the 24-month aged cheese is “specially selected” by Formaggi Zanetti, an Italian company that exports cheeses around the world.
9. PureOlogy moisture hair care: Speculation

Rumor has it that those affordable sets of cream-and-purple Kirkland Signature Moisture hair care bottles have high-end origins.
On Reddit and around the web, you’ll find a lot of speculation that L’Oréal’s PureOlogy division could be behind Costco’s shampoo and conditioner. However, there doesn’t seem to be much evidence.
The bottles look pretty similar, and reviewers online suggest Kirkland’s product is a fine replacement for the PureOlogy version. Take from that what you will.
10. Kimberly-Clark diapers: Confirmed

Kirkland Signature Diapers are made by Kimberly-Clark, the same manufacturer responsible for trusted nappies such as Huggies and GoodNites.
Costco finance chief Richard Galanti confirmed the connection in a 2017 interview with the Wall Street Journal. Costco had asked both Kimberly-Clark and rival corporation Procter & Gamble to produce diapers under the Kirkland brand, however only the former agreed.
Parents will notice that the only name-brand diapers sold at Costco are Kimberly-Clark’s Huggies. Procter & Gamble’s Pampers are nowhere in sight.
11. Reynolds aluminum foil: Confirmed

Costco partnered with New Zealand-based Reynolds of aluminum foil fame to produce its Kirkland Signature Foodservice Foil.
The proof is on the packaging, with the Reynolds logo proudly displayed on the shiny blue boxes.
The Kirkland foils come in larger sizes than the regular Reynold foils on Costco’s website, and their higher prices reflect the difference.
12. Gordon Biersch beer: Plausible

Depending on where you live, your Costco’s Kirkland craft beers could originate from one of two places. The Takeout claims that Kirkland beers on the East Coast come from Matt Brewing in New York and that beers in the West link to Gordon Biersch.
The publication says West Coast Kirkland beer bears the name “Hopfen Und Malz Brewing Co.” on the label. The site Mashed adds that the address of Hopfen Und Malz matches that of Gordon Biersch in San Jose, California.
Meanwhile, Mashed says, beer on the East Coast bears the name Bricks and Barley Brewing Company from Stevens Point, Wisconsin. It’s unclear whether this company is related to Matt Brewing.
13. Chinet cups: Confirmed

A staple at house parties, Costco’s giant packs of disposable red cups come from a familiar place.
The packaging clearly bears the blue Chinet logo under “Kirkland Signature” and next to the bold title “The Big Red Cup.”
The American company Chinet has produced disposable tableware such as plates, bowls and cutlery for over 90 years and sells them through other big retailers like Target.
14. Humboldt Creamery ice cream: Probable

After filing for bankruptcy in 2009, California’s Humboldt Creamery was sold to competitor Crystal Creamery and started selling its products nationwide through retailers like Walmart.
ABC’s KRCR News reported in 2016 that Humboldt has been manufacturing vanilla ice cream for Costco under their Kirkland Signature house brand.
However, Humboldt Creamery’s vanilla ice cream has also appeared under its own name at Costco, and both products have disappeared from store shelves at times — so the supplier situation may not have settled yet.
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