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​The Flavor Brief​

A weekly letter about food, science, and why things taste the way they do

​Read Past Newsletters​

Hi Reader

Have you ever picked up two identical-looking peaches from the same crate, only to find that one is a honey-sweet explosion and the other is muted, even mealy?

In the kitchen, we tend to blame ourselves, the farmer, or the season. But part of the answer is stranger. At some point during that fruit's development, pieces of DNA may have moved.

These are called transposons, or "jumping genes." They don't change your fruit in real time, but earlier in development they can shift position in the genome and influence how traits like color, aroma, and sugar are expressed.

We know this because of Barbara McClintock.

In the 1940s, working largely alone, she looked at corn under a microscope and saw something no one else believed: the genome isn't fixed. Parts of it move. When they do, they can change how traits show up, from the color of a kernel to how a plant grows.

Her work was dismissed for years. It didn't fit the idea of DNA as a stable blueprint. She stepped back from publishing, continuing quietly, until decades later the field caught up. In 1983, she was awarded the Nobel Prize in Physiology or Medicine. By then, what she had seen in corn had reshaped how we understand genetics.

Today, we see traces of that movement everywhere.

In speckled corn. In striped apples. In white grapes that came from red ones.

Even peaches and nectarines are nearly identical. A small genetic change determines whether the skin is fuzzy or smooth.

Sometimes these shifts happen near genes tied to aroma and flavor. Tomatoes can vary in how strongly they produce aromatic compounds. Strawberries can differ in fragrance. Blood oranges turn red only when a pigment gene is activated by cold.

But this is only part of the story. Ripeness, storage, and environment still do most of the heavy lifting. Which is why two pieces of fruit from the same crate can taste completely different even when they look the same.

Recipes assume consistency. Nature doesn't. So the job isn't to follow instructions perfectly — it's to pay attention. Taste as you go. Adjust. Work with what's in front of you, because what's in front of you has already been shaped by biology, chemistry, and a little unpredictability. Sometimes by the season. Sometimes by how it was stored. And sometimes, quietly, by a genome that moved.

That's the thread we're pulling on this season in Flavor Forward — what actually builds flavor, and why. We start with fat.

On screen this week

FLAVOR FORWARD - IS FAT FLAVOR? If you find the chemistry of umami fascinating, you’re going to love our Season 2 premiere. For decades, we were told there were only five basic tastes. But scientists are now closing in on a sixth: Oleogustus. Is fat just a texture, or does it have a secret chemical signature of its own? Watch now on YouTube →

THE RECIPE

This week's recipe is one I keep coming back to — simple enough for a Tuesday, interesting enough to think about all week and it's at America's Test Kitchen.

Blueberry Rhubarb Cornmeal Pudding I don’t think people say "blubarb" anymore the way they did a few years ago; that trend came and went. But what has lasted the test of time is the bright fruity combination of juicy blueberries with rhubarb. This cornmeal pudding has a thin golden crust on top and a soft layer underneath filled with the jammy and sweet juices of blueberries and rhubarb. With a hint of tartness held together by the rich sweetness of cornmeal, it’s a simple pudding that comes together with ease and is equally magical. Get the recipe →

Cinnamon Cacao Nib Cookies What if your chocolate chip cookie tasted less like a snack and more like something from a high-end chocolatier?Enter the Cacao Nib. These cracked, unprocessed cacao beans bring an unapologetic bitterness and fruity acidity that cuts right through the sugar. Paired with deep, caramelly panela and a hint of cinnamon, it’s a sophisticated nod to Mexican chocolate that's well worth your weekend. Get the full recipe hosted at ATK Get the recipe →

THE SCIENCE EDIT

THIS WEEK'S PRINCIPLE

The Enzyme Battle in Your Pantry

Cooking tip:

​Last week, we broke down the "Umami Multiplier"—the mathematical magic that happens when glutamates and nucleotides meet on your tongue. We talked about how a cheeseburger or a Caesar salad is secretly a high-level chemistry experiment.

But many of you asked: "How do I maximize this in my own kitchen without just adding more salt?"

The answer is the Dried Shiitake. It is a rare "all-in-one" umami bomb, containing both glutamates and the powerful nucleotide guanylate. However, most home cooks accidentally destroy that flavor before the mushroom even hits the pan.

The "Savory Stink" of Lenthionine

When you open a bag of dried shiitakes, you’re hit with a pungent, meaty aroma. That’s lenthionine. This cyclic sulfur compound is created during the drying process and puts shiitakes in the same "craveable" chemical family as truffles and garlic. But to keep that depth, you have to manage the enzymes.

The Thermal Tug-of-War: Builder vs. Destroyer

Your mushroom soaking liquid is a battlefield between two enzymes with very different agendas:

1. The Destroyer (Nucleotidase): This enzyme is most active between 113°F–122°F (45°C–50°C). Its only job is to break down guanylate into tasteless guanosine. If you soak your mushrooms in warm tap water, you are giving this enzyme a head start to wipe out your umami.
2. The Builder (Ribonuclease): This enzyme thrives between 140°F–158°F (60°C–70°C ). It actively produces more guanylate from the mushroom's RNA, supercharging the savory signal.

The "Golden Hour" Protocol

To win the battle, you need to be strategic with your temperatures:

• The Cold Start: Always rehydrate dried shiitakes in cold water in the fridge. This allows the mushroom to plump up while keeping the "Destroyer" enzyme dormant.
• The Fast Jump: When you’re ready to cook, don't let the liquid come to temperature slowly. Bring it rapidly past the 122°F (50°C ) danger zone and hold it near 149°F (65°C) for a few minutes. This bypasses the destruction phase and maximizes the "Builder" phase.
• The Synergistic Finish: Pair those shiitakes with dried Porcini. While the shiitake provides the "amplifying" guanylate, the porcini brings a massive load of glutamate and earthy 1-octen-3-ol. Together, they add flavor and they multiply the perceived intensity by up to 8x compared to the ingredients alone!

Kurihara K. Umami the Fifth Basic Taste: History of Studies on Receptor Mechanisms and Role as a Food Flavor. Biomed Res Int. 2015;2015:189402. doi: 10.1155/2015/189402. Epub 2015 Jul 12. PMID: 26247011; PMCID: PMC4515277.

Yamaguchi, S. (1967).The synergistic taste effect of monosodium glutamate and disodium 5’-inosinate.Journal of Food Science, 32(4), 473–478.

The Flavor Equation by Nik Sharma, Chronicle Books (2020)

What I'm Cooking

Last weekend I had some friends over and spent most of the day at the grill — smoked ribs with a tangy homemade BBQ sauce that came together better than I expected. I'll admit to one shortcut: I forgot to grab potatoes at the store and didn't realize until it was too late, so store-bought mashed potatoes filled in without complaint. The sungold tomatoes in the garden are going strong right now, so I pulled a handful and threw together a quick tomato basil salad with a splash of balsamic and good olive oil. A good afternoon, potato situation notwithstanding.

COMING SOON!

Fundamentals of Flavor is available for preorder now — this one has been six years in the making and I'm genuinely proud of it. If you've been cooking with me for a while, this book is for you. Preorder Now →

Thanks for reading, I hope something here makes it into your kitchen this week.

Nik