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Castelvetrano vs Kalamata vs Black Olives: How They're Made & What's on the Label

Audio from the Clean Food Score video of the same name; the video shows the labels and scores on screen.

Most canned black olives started out green: they're darkened with air and an iron salt called ferrous gluconate. We explain Castelvetrano, Kalamata, green and stuffed olives, black olives nutrition and sodium, and the cleanest jars we've scored (as of October 2026).

Full guide and the products we checked
Check any ingredient list free

Products featured (Amazon links, with our 0–100 label score):
• Kosterina Spicy Kalamata Olives — 71/100
As an Amazon Associate I earn from qualifying purchases.

Chapters
0:00 The Short Answer
0:46 Green or Black?
1:24 How Black Olives Are Made
2:10 Castelvetrano Olives
3:03 Kalamata Olives
3:54 Green Olives
4:33 What the Brine Can Add
5:17 Stuffed Olives
6:04 Black Olives Nutrition and Sodium
6:51 How to Read an Olive Label
7:31 The Jars We've Scored
8:23 Your Turn

Product scores are Clean Food Score's 0–100 label scores as shown on cleanfoodscore.com on 2026-10-18. Recipes change, so read the package you buy. We read labels; this is not medical advice.

Music
"Almost Bliss" Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 4.0 License
creativecommons.org/licenses/by/4.0

"Carefree" Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 4.0 License
creativecommons.org/licenses/by/4.0

"Fresh Air" Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 4.0 License
creativecommons.org/licenses/by/4.0

"Friday Morning" Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 4.0 License
creativecommons.org/licenses/by/4.0

Sound effects: Kenney (kenney.nl), CC0.

#olives #castelvetrano #kalamata