I’ve seen a number of YouTube videos demonstrating higher brix values for homegrown veggies compared to those bought in a store or at a farmer’s market.
But I don’t think I’ve ever seen a brix test done on crops grown in the same garden, with the same base soil, but with different soil amendments.
Specifically, I’d like to see if veggies grown in soil amended with rock dust will have higher brix values than those grown in the same base soil, but with no rock dust.
This video will be my first step toward trying to answer this question.
Brix readings represent the percentage of soluble solids in a solution.
So, a brix value of 8 means that 8% of a solution consists of soluble solids.
These values can be determined using a brix refractometer.
The most prevalent soluble solids in fruits and vegetables are sugars, pectins, organic acids, and amino acids.
Minerals are also present but at a lower level.
All of these solids contribute to the brix value,
but because sugars are most prevalent in fruits and vegetables, brix readings are often used as an estimate of sugar content.
The theory behind rock dust increasing brix values is that plants will take up the minerals in rock dust,
thereby increasing their mineral content and total level of soluble solids, resulting in higher brix readings.
So, to get things started, I decided to test 3 sweet million tomatoes from both my control and rock dust groups.
I made sure to pick only tomatoes that were very ripe and nearly ready to fall off the vine.
I started with the control group tomatoes, which were grown in soil with no rock dust added.
I squeezed juice from the first tomato onto the refractometer prism, making sure there was enough juice to cover the entire prism surface.
I closed the daylight plate over the prism and looked into the eyepiece to determine the brix reading.
The view inside a refractometer looks something like this.
The brix value is the point at which the blue and white colors meet.
For the first tomato, the blue and white met right at 9.
After each test, I cleaned off the prism and daylight plate with distilled water to ensure the integrity of each individual test.
I then moved onto the second tomato, which also had a brix value of 9.
Finally, the third tomato had a reading of 9.2, giving us an average of 9.06 for the control group.
According to highbrixgardens.com, a value of 8 is good for a tomato, so I was pleased the control group was above that.
But I have to admit I was a little disappointed not to get an excellent reading of 12 or more, and hoped for a higher reading from the rock dust group.
The rock dust tomatoes were grown in the same base soil as the control group.
However, the soil was amended with one pound of rock dust per square foot.
Following the same procedures as with the control group, the first rock dust tomato had a brix reading of 9.
The second had a value of 9.2, and the third had an 8,
giving the rock dust group an average of 8.73, which was just a little lower than the control group’s 9.06 average
and definitely short of the excellent reading of 12 that I was hoping for.
So, clearly this was not the dramatic slam dunk that some might expect for the rock dust tomatoes.
That said, this was the first of many tests to come and a different picture could emerge by the end of the season.
I’ll continue to brix test tomatoes as well as peppers, celery, and hopefully lettuce and beets in the fall.
I’ll share the final results with you at the end of the growing season.
At that point, I should have a much better idea if rock dust minerals had any impact on the brix values of veggies grown in my garden.
Before closing, I’d like to thank fellow gardener and biologist Stephen Legaree for sharing his expertise
and helping me better understand what brix testing is about and how rock dust might have an impact on brix readings.
If you haven’t already checked out Stephen’s channel, I’ll provide a link at the end of this video.
Well, that's all for now.
Thank you very much for watching,
and until next time remember
you can change the world one yard at a time.