Wednesday, August 08, 2011
Brix Testing Tomatoes to Measure Sugar Content
Over the past few years, I’ve told anyone who would listen that Farmscape tomatoes are the best I’ve ever tasted. Then again, I’m not exactly an unbiased observer. Taste is subjective, and my opinion is biased by the gallons of sweat and more than a couple of drops of blood I’ve spilled growing our tomatoes.
Enter Brix testing. Brix is a measure of the sugar content of a liquid. Using a brixrefractometer, you can measure what percent of a fruit’s juices are made up of sugar. Using brix testing to measure taste is common in agriculture–it is often used by commercial winegrowers to measure the quantity of sugars in their grapes, and can be used to diagnose nutrient deficiencies.
Sugar content is obviously not the only factor in determining how a tomato tastes; I myself prefer tomatoes with a bit of tartness. Still, because there is no way to objectively measure deliciousness, brix is the best tool we have to measure tomato quality and render a pseudo-objective judgment. As it turns out, you can learn a lot from brix. Food blogger Jon Rowley has brix tested tomatoes for years, and says that brix is a pretty good proxy for taste. According to Rowley, tomatoes with a score of 4.0 – 5.0 tend to have “undistinguished taste,” while a brandywine that scored 14.0 was “unbelievable…A flavor to make an Italian grandmother weep with joy.” Last year, Rowley hosted hosted a “10.0 Brix Tomato Challenge” in which he challenged farmers at his local market to grow a tomato that scored 10.0 or above.
While Rowley’s challenge is already over and wasn’t exactly directed at Farmscape, we decided to take it up anyway. We purchased this brix refractometer and we assembled a hodgepodge of tomatoes from different sources, and tested them over the course of a couple of weeks.
Meet our test subjects!
Grocery Store Tomatoes
We purchased three grocery store tomatoes–a standard red tomato, a red heirloom tomato, and a “black” heirloom tomato. Here were the results:
Large red heirloom – 4.5 (Grocery Store)
Boring standard red tomato – 3.5 (Grocery Store)
Large black heirloom – 4 (Grocery Store)
Average Score: 4
Farmer’s Market Tomatoes
We purchased and tested six different tomatoes from the Pasadena and Hollywood farmer’s markets, yielding the following results.
Roma – 5 (Farmers Market)
“Heirloom” – 5 (Farmers Market)
Round Red – 4 (Farmers Market)
Orange Heirloom – 4.5 (Farmer’s Market)
Small Dark Red Heirloom – 3 (Farmer’s Market)
Red Farmer’s Market Heirloom – 4 (Farmer’s Market)
Average Score: 4.25
Farmscape Tomatoes: Sun Golds, Red and Yellow Brandywines, Cherokee Purple, Green Zebra.
Cherry – 7 (Pasadena)
Black Prince – 7 (Pasadena)
Momotaro – 6 (San Gabriel)
Momotaro – 6 (Pasadena)
Brandywine – 6 (Pasadena)
Black Prince – 5 (Pasadena)
Sun Gold – 9 (Venice)
Green Zebra – 5 (Venice)
Momotaro – 6 (Venice)
Yellow Brandywine – 6 (Venice)
Cherokee Purple – 7 (Venice)
Red Brandywine – 6 – (Venice)Average Score: 6.46
Our data indicates that your taste buds don’t lie: Farmscape tomatoes are objectively delicious. Our tomatoes scored substantially higher on average than either grocery store or Farmer’s market alternatives. Although our test was decidedly non-scientific, the results were remarkably consistent. All of our tomatoes scored between 5 and 9, with the majority scoring either 6 or 7. Farmer’s market tomatoes scored between 3 and 5.5, and grocery store tomatoes scored between 3.5 and 4.5. Every tomato from a Farmscape garden tested as high or higher than every grocery store or farmer’s market tomato we tested.
The Farmscape tomato scores were skewed a bit upwards by the sun gold cherry tomatoes, which received scores of 8 and 9. Because cherry tomatoes tend to score a bit higher on average, our test was slightly unfair to the competition. Before you call the sample size police or the federal bureau of scientific method, take note of the consistency with which our tomatoes scored higher. At the very least, I’m willing to take this as proof that my boosterism for Farmscape tomatoes is well-founded.
Hopefully, this is just the beginning of our brixperimentation. The summer season is winding down right now, but our plan is to post brix scores for other Farmscape produce during the coming winter season and next summer.