How Sweet It Is: Measuring Brix
I have a sweet tooth. Whether it’s due to the influence of my British granny or to an uncontrollable genetically-based craving for energy, I just love sugar.
Let me clarify. I don’t love saccharine-sweet breakfast cereal, nor high-fructose-corn-syrup-laced soda or sugar-filled cake. It’s straight-from-the-sun ripe fruit that I adore. Juicy farmers’ market Korean pears, fuschia slices of watermelons, mouthwatering Honey Crisp apples, they’re all my favorite sugary snacks.
Last weekend, I set out to learn just how sweet the fruits are that sate my cravings. The metric by which winemakers and other fruit growers measure sweetness is called “Brix.” One degree of Brix is equal to 1 gram of sucrose per 100 grams of solution. Producers around the world use a device called a refractometer to measure the brix, and use this information, alongside other factors like the weather, to decide when to harvest.
On our family farm, there’s a refractometer handy, and plenty of fruits and vegetables to test. Table grapes burst their skins with nectar, red kuri squash reach peak sweetness, and even the last ears of sweet corn explode with sugar.
I collected a few samples out in the fields, and assembled a sweet cornucopia at our kitchen table.
The refractometer is simple to use. It has a small surface onto which one can squeeze the juice of the item to measure, and then holding it towards the light, one can read the scale to see the Brix.
In the absence of wine grapes, I used our table grapes. I started out with a green Concord, tannic and tart to taste. 8 Brix. Moving to a luscious, ripe black Concord, I could taste the difference in sweetness: 14.2 Brix. But when I tested another ripe table grape, a dark red Catawba that seemed less sweet, it was actually much higher: 17! What’s going on here? Sweet tastes sour?
Acidity! The acidity of the grape balances out sweetness, even though it has a higher sugar content.
Here’s another example. Brix of fresh apple cider? 11. Brix of orange juice, which tastes more tart? 12!
I love this lesson as it applies to wine. These fruits and their nectar are tasty examples of the interplay of fruit, acid, and sugar. They’re a lovely reminder of why balance matters, and why winemaking is both a science and an art.
And the surprise of the afternoon experiments? An ear of corn, a Japanese variety called “Mirai,” hit 13 – 14 brix. Now that’s “sweet corn!”