Making the Case for a Fermented Passover

We’ve all heard the story of the Israelites hastily leaving Egypt and not having time for their bread to rise. We know this as the explanation for why we’re forced to eat matzah, or unleavened bread. But are there any other explanations for why we scorn chametz, or leavened bread, during the 8 days of passover?

Lets first look at the word chametz which is a cognate to the Aramaic word meaning, “to ferment or leaven” and the Arabic ḥamuḍa, “to be sour”, “to become acidic”. Long fermented bread is more sour & aptly named sourdough. And in the ancient times, all bread was sour. Humans didn’t have technology to mass produce light & sweet breads — it was all heavily fermented, sour, and made good use of the wild micro-organisms in the environment as a fermentation starter. Ancient breads were likely what we would now call ‘rustic’ sourdoughs. And the starters humans used to kick-start each new bread batch was maintained throughout the year. Many think that passover was used as a time for folks to restart that old sourdough starter. Think wiping clean your pantry and starting a fresh batch of fermented dough with all new microbes.

In the past, this was a way to keep your bread fresh & wipe out old & ‘unclean’ micro-organisms. And so folks came to associate ancient sour breads with uncleanliness. Think of the symbolism that we use nowadays for chametz and its ‘corrupting influence’, ‘souring’ our souls with false pride.’ This was potentially an ancient survival tactic, keeping our bread fresh and stale microbes at bay.

Cut to modern times where anti-microbial soaps and hand sanitizer is commonplace and where our food (and soil in fact) is sanitized, pasteurized & sterilized. This has led to an equally sterilized body. Our intestines are not brimming with life & rich diversity anymore and we are only beginning to understand the negatives of our modern war on bacteria. Maybe it is time to rethink this war, this this doctrine against sourness. And maybe passover is the perfect time to explore the upsdie of chametz thru a reinterpreted seder plate where we can together investigate the value that ‘unclean’ bacteria play in our lives!

This coming passover, I plan to incorporate fermented foods on my seder plate. I plan to lead a discussion on the ubiquity of fermentation in Jewish cuisine and put it specifically within a Passover context. To symbolize the harsh suffering and bitter times Jews endured as slaves, I will incorporate lacto-fermented bitter & pickled greens on my seder plate. And my karpas will be dipped into sauerkraut brine, which is essentially alchemically activated salt water. The brine will represent less the Israelite tears and more the conductive material for transformation. Around our seder plate, we will discuss how the pain of slavery can be a transformational experience towards community connection and solidarity in the same way that brine & microbes are a transformational experience for the cucumber on its way to becoming a pickle!

So let us rethink chametz together and find ways to incorporate traditional fermented foods on our seder plates. And let us reinterpret our passover traditions and redefine them in ways that make sense today.

Jeremy Ogusky, Studio potter (, fermenter, and founder of the Boston Fermentation Festival (