Is this made in Korea?

Grown in China, processed and packaged in Korea. I would give it a pass and pay the premium for the Korean grown stuff. Cant speak for difference in quality but if you know anything about groundwater contamination and farming practices in China the Korean grown stuff starts looking a lot less expensive.

Could red pepper flakes from a regular American grocery store be substituted for this? How are they different?

It's a different type/breed of pepper. American red pepper flakes typically use dried jalapeno pepper or cayenne peppers. Gochugaru is a Korean red chili pepper (called taeyang-cho). Is you sub the flakes, your dish will taste "fine", but it won't taste authentically "korean" - just my opinion. It'll taste like a spicy soup, or spicy meat, or whatever you're making like a fusion-style cuisine. I would never sub the flakes. Once you take a sniff of the Korean gochugaru you will know the difference - there is a sweetness, smokiness and depth to the flakes. Hope this helps.

Can this be kept in the refrigerator for long?

I've keep it in refrigerator for 2 years at a time. Still great.

How many cups of chili flakes does this contain?

There are 5.66 cups of flakes in the package based on the service size info on the package. 1088 quarter teaspoons is 272 teaspoons. Plus that into a converter to get 5.66 cups.

Package Dimensions	37.59 x 27.3 x 7.01 cm; 1.36 kg
Units	1419.53 Milliliters
Brand	Taekyung
Format	Powder
Age Range Description	Adult
Special Feature	Kosher
Package Information	Bag

Tae-kyung (3 LBs) Korean Red Chili Flakes, Gochugaru, Hot Pepper Type Powder By

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