Wine Uncorked: Mevushal, Vineyards, and the Kosher Harvest

Welcome to Keeping It Kosher, where Rabbi Ezra Sarna takes us behind the scenes of the kosher world. This week, we are sitting down in the OU Kitchen with Rabbi Nachum Rabinowitz, the OU’s resident expert on kosher wine and alcohol, to discuss the incredible scale, complexity, and unique halachos of massive kosher wine programs across the globe.

In this episode, we cover:

• Why Wine is Unique: The foundational stringencies of wine in halacha, historical handling restrictions, and why simple grape juice is treated the exact same way as wine once it’s pressed.
• The “Mevushal” Question: What “mevushal” actually means today, why it is critical for catering and food service, and how additives or dilution impact the brachos and Arba Kosos.
• The 44-Man Harvest: A behind-the-scenes look at what it takes for a major winery to operate with a fully Shomer Shabbos team during a grueling 20-day harvest window.
• Technology & Halacha: How modern automation—like automatic pump-overs, high-tech drip sampling, and temperature divert systems—helps solve ancient halachic challenges on the factory floor.

Whether you are picking out the perfect bottle for your Shabbos table or just want to understand the extreme logistics behind the hechsher, this episode provides a fascinating look at the reality of what goes into every glass.

Listen, Rate, and Subscribe!

Is there a kashrus topic you’d like us to explore? We’d love to hear from you – share your ideas in the comments or leave us a review.

Have kashrus questions? Reach out to the OU Kosher Hotline at kosherq@ou.org or 212-613-8241.