MilkRun Basics: Horseradish

Chasing the White Dragon — Why We Like Horseradish

by Ian B. Wilson

Since people first started domesticating wild plants and breeding them for flavor, we’ve had an insatiable fascination with their dangerous side.

Analyzing food history shows that perhaps only second to sweetness, pungency is king when it comes to the invisible forces guiding our agricultural trends. Case in point, the piquant and unique “heat” of the baking spices we’re familiar with now were once the highest valued and most sought after luxuries that anyone, in any far corner of history, could lust after.

For most of human history, food was, by most measure, bland. And that’s especially true by today’s standards.

Whether you lean into a co-evolutionary perspective, a-la-Botany of Desire, or simply a more free-form, chaotic cascade of coincidences, it’s impossible to deny that people like spicy. A lot. A lot, a lot. And for most of our history, our relationship with spice has been ruled by two plant families, or maybe more specifically two chemical compounds:

  • Capsaicin, the volatile compound in chili peppers
  • Allyl isothiocyanate (mustard oil) the colorless oil  responsible for the pungent taste of mustard, horseradish, and wasabi.

The topic of today’s lesson is the latter.

The Humble Horseradish

While it is true that during the last couple hundred years chilis have found warm reception in nearly every cuisine the world over, for most of human history they were only present in Mexico, their place of origin. Conversely, the “cold fire” found deep in the roots and leaves of brassicas has been a desirable, albeit particularly elusive, sensation for people on every continent, since prehistory.

In German, it’s called meerrettich (sea radish) because it grows by the sea. Modern etymologists now believe that the English mispronounced the German word “meer” and began calling it mare-radish… though eventually it became known as horseradish. And in this case “horse” stuck as it aptly described its often large physical size and strength of flavor. Many food traditions across Europe, the Middle East, and Asia evolved to capitalize on its fleeting, intense, cool-heat. A veritable culinary swiss army knife! Just as it acts as a natural foil to gamey and rich flavors, it shines and enlivens — in an almost ethereal, effervescent way — delicate proteins and vegetables.

There is an astounding amount of chemistry that goes into understanding all the intricacies of why mustard oil does what it does to us and our delicate sensory organs. Luckily, the core of it and its application, couldn’t be simpler. In short, there is a chemical in horseradish that’s presence suggests an evolutionary retaliation to deter would-be predators. When the naturally occurring enzymes found tightly locked up in the undamaged cells of the plant come into contact with oxygen they explode in a chain reaction that turns sinigrin (a glucosinolate found in some brassicas like broccoli and black mustard) into mustard oil. In nature, this whole process would presumably take place in ambient temperatures and a fairly neutral environment (in terms of ph, that is.) Almost instantly, whoever bit into said root would feel a surge of white, blinding heat fill their eyes, sinuses, and mouth, inciting an involuntary gag reaction. And if that wasn’t enough, a large dose of these chemicals hitting your stomach (especially when its empty) is enough to make even large mammals nauseas. Oof.

And what should all of this mean for us? Well, if you have a sadist streak and an ounce of cunning about you… it’s a recipe for pleasure. We are going to take the source of all of this magic, build an environment where its chemical symphony can unfold, and bask in its cold, spicy glow.

Happily, we have access to fresh, amazing horseradish, and thought we’d empower you, dear reader, to take a crack at a very satisfying (and surprisingly easy!) method (or three) for reveling in freshly grated and prepared horseradish in your own home.

How To Make Prepared Horseradish At Home


  • Horseradish
  • Ice
  • Vinegar*
  • Sour Cream (optional)
  • Xanthan Gum (optional)
  • Neutral oil (optional)

*a note on vinegar: seek out a vinegar that you actually enjoy the flavor of. Using distilled vinegar is functional, but flavorless. Try using a nice Champagne vinegar to push the limits on how bright your food can shine, or an unfiltered apple cider vinegar to pay homage to this condiment’s low country roots.


A blender or a microplane.

Really, that’s it.

Method 1

The dead simplest and freshest option:

  1. Fill a 16oz jar with 10oz of water and 2oz of the vinegar of your choice
  2. Peel a horseradish root (you might want to open a window) and submerge it in the brine
  3. After its had 30 min or so, grate with a fine-toothed microplane

It is going to be at its very sweetest (you might be surprised just how sweet, actually) and prickly this way, the only drawback to this method, is the involvement you have signed yourself up for, grating fresh horseradish on everyone’s roast beef to order… But, good on you!

Method 2

The most stable, and classic option (also, science):

  1. Peel 300g. of horseradish and cut into ½” coins and chunks. Throw it in a blender (or a strong food processor would do)
  2. To the horseradish, add 100g of ice, and pulse a few times

The goal here is to do 2 things: 1) to damage/bruise the majority of the cells and start the cascade of chemical reactions that make it spicy and 2) drop the temperature of the environment dramatically, thereby slowing all of the oxidation down… more on that in the next step.

  1. Wait about 10 minutes.

There is a sort of bell curve of intensity with how spicy horseradish can get. Once you introduce something acidic like lemon juice or vinegar, it destroys most of the enzyme activity, and chemically “freezes” the process. In the cold ph-neutral environment the horseradish bell curve is much longer and easier to “catch”  In our trials (and you can find other folks online who experiment with these things too…) we found the greatest intensity to be after waiting between 7-10 minutes after blending but before adding acid.

  1. Add 50-100g of vinegar and salt to taste. Blender or process to your desired consistency, we like it super smooth.

Method 3

You know, cause some people like to get lush with it:

  1. Follow steps 1-4 of Method 2
  2. Add  ¼ Cup of sour cream

(Or as a vegan alternative add 1.5 tsp Xanthan Gum and stream ⅓ Cup of neutral oil into your finished horseradish while it’s still in the blender)

Like all fresh foods, horseradish is better when its fresh. After 10-14 days it will lose a lot of its potency, so keep it in the fridge and enjoy the heat.

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