Quick Answer: What Makes a Mezuzah Kosher
A mezuzah is only kosher if the scroll inside is:
- Handwritten on parchment by a trained Jewish scribe (sofer).
- Letter-perfect, with no cracks, smudges, or missing letters.
- Made with kosher materials—parchment from a kosher animal, ink, and quill.
- Written in the correct order
- Checked and certified by qualified experts.
If any of these requirements are missing—even if the case is beautiful—the mezuzah is not kosher and does not fulfill the mitzvah.
This is why certification is critical. To the untrained eye, all scrolls look the same, but only an expert can determine validity. The STaM Project exists to ensure Jews everywhere can access mezuzot that are truly kosher.
Why This Question Matters
Many people assume that when they buy a mezuzah from a Judaica shop or online store, it will naturally be kosher. Unfortunately, that’s not always true.
- Printed scrolls are often sold as kosher, but they are not valid under Jewish law.
- Cheap mezuzot may contain machine-made scrolls or incomplete texts.
- Faded ink or even one broken letter invalidates the scroll.
As Jewish Action has reported, the mezuzah industry has long lacked consistent oversight. New initiatives, like OU Kosher’s STaM certification program, are helping to change that—but awareness is still key.
Breaking It Down: What Makes a Mezuzah Kosher
1. The Mezuzah Scroll Must Be Handwritten
A kosher mezuzah scroll (klaf) is painstakingly written by a sofer with ink and quill on parchment. Every letter must be formed according to precise halachic rules.
- Printed scrolls? ❌ Not kosher.
- Photocopied scrolls? ❌ Not kosher.
- Handwritten with errors? ❌ Not kosher.
This is why certification is essential—you can’t tell by looking at the outside of the case whether the scroll is genuine.
2. Every Letter Must Be Perfect
Jewish law requires the scroll to be letter-perfect. That means:
- No smudges or cracks.
- No broken or missing letters.
- No touching or overlapping letters.
If even one letter is damaged, the mezuzah becomes pasul (invalid).
3. Kosher Materials Only
The parchment must come from a kosher animal, the ink must be made according to halacha, and the writing instrument is traditionally a quill. These details safeguard the sanctity of the text.
4. Written in the Correct Order
The sofer must write the scroll in the precise order of the verses. Skipping, erasing, or rewriting out of order invalidates the mezuzah.
5. Certified and Checked
Finally, a mezuzah must be inspected to confirm its validity. Without oversight, invalid mezuzot flood the market. This is why organizations like The STaM Project are so important—they provide certification, education, and trusted sources for purchase.
Why Certification Matters More Than Ever
The mezuzah is a mitzvah deeply tied to Jewish identity, faith, and protection. Yet many Jews unknowingly hang mezuzot that are not kosher.
Certification addresses this by:
- Ensuring authenticity — scrolls are handwritten and halachically valid.
- Protecting consumers — so families don’t waste money on fake or invalid mezuzot.
- Building awareness — teaching communities why validity matters.
OU Kosher’s STaM initiative and projects like STaM Project’s Where to Buy list are transforming the way mezuzot are trusted and purchased worldwide.
The Role of the Case vs. the Scroll
It’s important to stress: the case is not the mitzvah—the scroll is.
While many people spend money on ornate silver or glass mezuzah cases, the real focus must be the scroll inside. A $200 case with a fake scroll is not a fulfillment of the divine command—worthless halachically. On the other hand, a simple plastic case with a certified kosher scroll fulfills the mitzvah beautifully.
To understand more about the scroll itself, see our earlier blog on mezuzah meaning.
Common Misconceptions About What Makes a Mezuzah Kosher
How to Check If Your Mezuzah Is Kosher
Since most people can’t read STaM script or identify flaws, the only reliable way is through:
- Certified purchase: Buy only from vendors verified by trusted organizations like The STaM Project.
- Periodic inspections: Halacha recommends checking mezuzot twice every seven years, and more often in humid or harsh climates.
- Rabbinic guidance: Local rabbis often know trusted sofrim or can recommend certified sources.
- QR code verification: Any mezuzah certified by The STaM Project comes with a unique QR code. You can scan the code and enter it on the STaM Project website, which will confirm whether the mezuzah has been verified by their experts. This gives buyers peace of mind that their mezuzah is authentic and kosher.
FAQs: What Makes a Mezuzah Kosher?
How often should a mezuzah be checked?
Twice every seven years, and more often if outdoors or in humid climates.
Can I buy a mezuzah online?
Yes—but make sure it comes from a trusted, certified seller. See Where to Buy a Mezuzah for guidance.
What if one letter is cracked?
Even one broken letter invalidates the scroll. A sofer may be able to fix it if done according to halacha.
Is a printed mezuzah ever kosher?
No. Printing does not fulfill the mitzvah. Only handwritten scrolls are kosher.
Conclusion: Ensuring Your Mezuzah Is Truly Kosher
So, what makes a mezuzah kosher? The answer is both simple and complex: a kosher mezuzah is a handwritten scroll, made with proper materials, letter-perfect, written in order, and checked by experts. Without certification, it’s nearly impossible for the average buyer to know whether their mezuzah is valid.
That’s why projects like The STaM Project exist: to safeguard this sacred mitzvah for Jews everywhere. Not only do they certify mezuzot, but every certified mezuzah comes with a QR code that you can check directly on their site. With one scan, you’ll know if your mezuzah was verified by their team.
Combined with initiatives like OU Kosher’s STaM program and the awareness raised by Jewish Action, the future of kosher mezuzot is more secure.
Your mezuzah is more than a ritual—it’s a connection to heritage, protection for your home, and a daily reminder of God’s presence. Make sure it’s kosher, make sure it’s certified, and make sure it carries a QR code you can verify with The STaM Project. That way, you know with confidence that your mitzvah is fulfilled.