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Why are My Radishes Spicy?

Any gardener or farmer can tell you– that radishes are always MUCH spicier when grown in hot weather than in cooler fall/ winter months. Beyond just radishes and mustards which have a spicy reputation, all brassicas like turnips, cabbage, broccoli, kale, etc. (read more about brassicas here ) can get a little bit in hot weather…. but WHY exactly? The answer is a chemical compound called Allyl Isothiocyanate (Sometimes referred to at AITC) These compounds are formed when the plant tissue is injured or mechanically disrupted.

Why are radishes spicy?

If you don't love the summer spice of brassicas– good news; Allyl Isothiocyanate can be reduced in several ways

  1. Heat: Allyl Isothiocyanate off-gasses at about boiling, roasting, or cooking your radishes/ spicy brassica is a great way to completely eliminate their spicy flavor.

  2. Osmosis: Allyl Isothiocyanate is also water soluble, so soaking your spicy veggies (or making quick pickles!) is a great way to temper the spice. It will not remove it completely, but it will dissipate the kick.

If you DO like a little spice in your veggies, I have even better news. The science is still inconclusive, but Allyl Isothiocyanate and many other plant metabolites like it have powerful anti-microbial, anti-inflammatory, and anti-cancer properties. This article in NATURE highlights promising anti-cancer findings, and this page in the Food and Nutrition Journal summarizes a whole lot of other promising research . I think it is probably safe to say generally that a little brassica spice is probably doing something supportive for our bodies. :-)

This time of year, it is still HOT and many of our early radish and arugula crops will have a little kick to their flavor. Consider leaning into the flavor and health benefits. Citrus dressings do a great job balancing the spice and bringing the flavors together. Try making coleslaw with your radishes the day before and give the spice some time to off-gas before eating. Or roast your radishes into a delicious soup (this one uses tops and bottoms!)

Last but not least, I actually just read this story a few weeks ago about the first ever mustard green bred specifically WITHOUT the enzyme to create Allyl Isothiocyanate.

Don't worry, we are not clamoring to grow this new mustard anytime soon, we love the spice, and hope you do too! It reminds me of the season and the constant change and changing flavors and joys of the seasons.

VRDNT’s Brassica Forecast.

Fall is the major Crucefer/ Brassica season as they do better in the cooler fall weather. Arugula and radishes will be the first to show up in your boxes (in the next 1-2 weeks) behind that we will have salad turnips, fresh daikon, watermelon radish, kale, collards and kohlrabi in the next month or two. Last but not least, broccoli, cauliflower, cabbage, and Rutabaga will be ready in the Last fall/ early winter. (Nov-December)


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