BEET KVASS: The Drink That Made Us Ask Better Questions

Where it all began

This article was one of the first real turning points for Wormwood Marmalade.

We didn’t begin by trying to reinvent biology. We were trying to understand why an old fermented drink kept appearing in stories about recovery, digestion and resilience. The deeper we looked, the stranger the question became.

Kvass didn’t give us an answer.

It gave us a riddle.

Years later, after following threads through microbiome research, gut ecology, inflammation, microbial metabolites and systems biology, we’d rewrite almost everything below.

The folklore survived.

Our explanation changed.

The first mistake: treating nutrients as the whole story

For decades we’ve often framed health like a shopping list.

Low iron?

Take iron.

Low B12?

Take B12.

Low magnesium?

Take magnesium.

Sometimes that works.

Sometimes it doesn’t.

The harder question is this:

Why does a body fail to use what it already has?

That question eventually became one of the recurring themes behind our later work.

Iron isn’t simply “low”

Iron biology is remarkably defensive.

When inflammation rises, the body produces hepcidin, a hormone that deliberately limits iron movement through the bloodstream. From the body’s perspective, this isn’t necessarily a mistake.

It’s a containment strategy.

Many microbes require iron to grow.

The body responds by changing iron availability rather than simply releasing more of it.

That makes anemia more complicated than a simple shortage.

Sometimes the problem is supply.

Sometimes it’s regulation.

Sometimes it’s the terrain in which regulation is occurring.

The microbiome doesn’t only matter because of who’s there

This is where modern research became far more interesting than our original article.

One of the biggest lessons emerging from microbiome science is that function and membership are not always the same thing.

A microbial community can temporarily improve its metabolic output without permanently replacing missing organisms.

Researchers are increasingly studying:

• short-chain fatty acids like butyrate,

• microbial metabolites,

• bile-acid transformations,

• postbiotic signalling,

• and why ecosystem function can improve before microbial composition fully recovers.

That distinction changed how we think about fermented foods.

What kvass may actually be doing

Our older article implied that kvass “brings the builders back.”

Today I’d phrase it differently.

Kvass may not permanently reseed an adult microbiome.

Instead, it may repeatedly change the conditions inside that ecosystem.

Think of it less like planting a forest.

Think of it more like improving the weather.

Fermented foods can contribute:

• organic acids,

• microbial metabolites,

• living fermentation organisms,

• and compounds that interact with the existing ecosystem.

Those effects may be temporary.

Temporary doesn’t mean unimportant.

The question that still hasn’t been answered

Here’s the riddle we still find fascinating.

If beneficial microbes are missing…

Why don’t they simply come back?

That question turns out to be much harder than it sounds.

The microbiome behaves less like a collection of isolated species and more like an ecosystem with:

• competition,

• nutrient constraints,

• signalling,

• host responses,

• and ecological barriers.

Adding organisms isn’t always enough.

The environment has to allow them to stay.

Folklore may have been asking the right question

Traditional cultures didn’t talk about:

• short-chain fatty acids,

• microbial metabolites,

• ecological resilience,

• or postbiotic signalling.

They simply noticed patterns.

“When you’re weak, drink kvass.”

Whether they understood the mechanisms is almost beside the point.

They were observing a system.

Modern science is now giving us better tools to investigate those observations.

The riddle continues

Kvass didn’t launch Wormwood Marmalade because it was a miracle drink.

It launched it because it exposed a recurring pattern.

Again and again we found ourselves asking the same question.

What if recovery depends less on forcing a missing component back into the system—and more on restoring the conditions that allow the system to reorganize itself?

We’re still following that question.

The drink stayed behind.

The riddle kept walking.