[EclipseFour20]

This might help....

Source: https://realfoodcampaign.org/content/brix


"Brix" is a technical term to measure and quantify the amount that light is bent passing through a fluid.

We have all seen the optical effect of a pencil sticking out of water. The straight pencil appears to be bent where it enters the water. This is because water has a different density than air, and so light travels at a different speed in water than in air. Thus, the pencil seems bent.



Actually, it is the light which is bent, not the pencil.

Fishermen must account for this optical displacement effect when they look into water for fish. A fish will appear to be in one location, but its true location may be a few inches away because light bends as it passes from water to air.



This difference between apparent and actual location is caused by this light-bending effect of the different densities of air and water.

Other liquids, glass, transparent crystals, many biological molecules, and other more exotic materials also bend a beam of light. This "refraction" is what gives diamonds and other gems their brilliance and sparkle.

What is Refraction?

"Refraction" is the technical term scientists use to denote this light-bending effect of water and other materials. Each substance will bend‚ or "refract"‚ light at a different angle, depending on its specific density. This angle of refraction also changes with certain other conditions, including especially temperature, frequency, magnetism, and concentration.




Scientists have carefully studied many materials to measure how much each will bend a light beam, and created ways to quantify this effect for each material. This numerical data is an index of refraction for that specific substance at a specific temperature.

Some substances‚ such as quartz crystal‚ bend different frequencies of light at different angles. Low frequency red light bends less than higher frequency blue. This separates a beam of light into a band of frequencies, which appears to our eye as a rainbow‚Äîa spectrum of colors, from red to violet.



This property is used by chemists in a spectrometer to detect and measure the elemental composition of complex molecules and mixtures. Astronomers measure refraction of a star's light as its signature spectrum to determine its elemental composition, and also distance from Earth and speed.

How does density affect refraction?

Back down on Earth, in agriculture, measuring this light-bending effect provides useful information about the density of fluids, such as soil moisture, irrigation water, plant sap, fruit juice, blood, milk, cell protoplasm, or other body fluids. Pure water at a specific temperature will bend light at a specific angle. However, any chemical dissolved in the water will change the density of that liquid, and thus change its angle of refraction.

We have all watched salt or sugar crystals slowly sink down in a glass of water, and seen the curling bands of light and shadow that swirl and whorl around the grains as they sink and dissolve. Those bands of light and dark are due to varying light-bending effects of different densities in layers of water around each disassembling, dissolving, descending crystal.

A wide variety of biological substances can increase solution density, and thus cause light to refract (bend) more as it passes through a watery medium:
1. dissolved minerals (salts, acids, alkali)
2. carbohydrates (simple sugars)
3. amino acids (proteins)
4. lipids (special case: oil & water don't mix; form thin films)
5. almost any molecule with covalent bonding
6. very large suspended particles (colloids)

Measuring this change in the angle of refraction can give helpful data and insight about the density and chemical composition of that solution.

How does this affect plant sap?

In the case of plant sap, it is primarily sugars in plant juice that cause refraction. This is because the primary activity of plants is photosynthesis‚ using sunshine to combine carbon dioxide and water to form sugars. This sunlight stored in carbon rings is the primary source of energy for most of biology on Earth, including humans, especially our nervous system.

Thus, the principal substance carried by plant sap fluids is these energy-rich carbohydrate chemicals: sugars‚ the sweetness of life.

Normally, the second most abundant refractive substances in plant sap are mineral ions. However, sugars are quite large compared to mineral ions. Each sugar molecule consists of at least two dozen covalent bonds in a molecule composed of twenty to two dozen or more atoms. Thus, sugars tend to affect the index of refraction more than minerals.

Thus, Brix is mostly a measure of sugars and minerals dissolved in water. however, many other chemicals may be present and contribute some small factor to the Brix reading.

What is a Refractometer?

A refractometer is the instrument used to obtain a brix reading. This simple, hand-held measures the amount of refraction (or bend) in a beam of light that passes through the plant sap. A conscientous nutrient-dense grower takes regular, routine field measurements of plant sap density.



Refractometers come in three basic types: optical, digital and laboratory. For growers, the first two are portable, handheld and simple to operate in the field.

How to use an optical refractometer

• squeeze sap out of a plant
• put 2 drops on the prism
• close the prism cover
• point to a light source
• focus the eyepiece
• read the measurement where light & dark fields intersect is the Brix number

Optical refractometers (above & left) require a few drops of solution to be spread thinly on the surface of a prism. Then, like a tiny telescope or microscope, you peer down a long hollow tube at the prism. Part of the light beam passes through the thin film of plant sap on the prism, while the rest bypasses this specimen.

An adjustment knob allows you to align light and dark areas on a screen to determine the angle of refraction, and thus the solution density. A scale in the viewfinder allows you to easily identify the Brix number.

Digital refractometers (right) are simpler to operate and easier to read. Just put a few drops of liquid in the well hole, and press the switch. The Brix number appears in the digital readout. Both types work great, although digital models require a battery to operate

Why is it called Brix?

Professor Adolf Ferdinand Wenceslaus Brix, a 19th Century German chemist (1798-1890), was the first to measure the density of plant juices. Europe's winemakers could not predict which of various grape juices would make the best wine. Being able to judge quality ahead of actual bottling was of immense importance in an industry where a bottle of the best wine might sell for hundreds of times more than a bottle of everyday wine.

Professor Brix's hydrometer worked, but it was cumbersome and required a tall graduate of juice to actually conduct the measure. This was OK for the vineyard wine cellar, but a nuisance to the grower in the field who wished to squeeze perhaps a single growing grape to judge its potential quality.

Professor Brix was greeted as a great hero when he emerged from his laboratory to claim his most generous prize. He was also honored by having the measuring process named after him.

Adolf Ferdinand Wenceslaus Brix (born February 20, 1798 in Wesel, died February 14, 1870 in Charlottenburg, Berlin) was a German mathematician and engineer.[1] The unit degree Brix (°Bx) for specific gravity of liquids is named after him.

Brix made a career as a civil servant in professions related to civil engineering, measurements and manufacture (1827 Bauconducteur, 1834 Fabriken-Commisionsrath, 1853 geheimer Regierungsrath) and retired in 1866 (when he was promoted to geheimer Oberregierungsrath). He was director of the Royal Prussian Commission for Measurements, member of a technical committee in the Ministry of Trade, and the technical building committee. He was also a teacher of applied mathematics at Gewerbeinstitut zu Berlin (1828–1850), as well as in higher analysis and applied mathematics at the Bauakademie, both of which are forerunners of the Technical University of Berlin.



Who was Carey Reams?

Dr. Carey A. Reams, a Florida native and agricultural engineer who ran a large lab in Orlando from 1931 to 1968, made Brix a popular method in food production. In his college years, Reams discovered huge differences in the mineral content of fruits and vegetables, depending on how and where they were grown. He retired to further his research and give seminars and lectures all around the country.

Reams developed a following of farmers because they found that his methods produced crops of far superior quality. For many years, citrus and grape growers had used the Brix measurement to evaluate the quality of their produce. Reams took that knowledge and formulated a Brix chart, which covers most of the common fruits, vegetables and forage crops.

Shortly after Acres USA began publishing its monthly magazine on ecological agriculture, Reams noticed the paper's contributors talked about higher quality food production, no one had a method to measure and monitor such quality. One day Reams walked into Charles Walters' office with a copy of his Brix chart. The reverberations have been felt from one end of agriculture to the other.

Reams verified that the "soft" rock phosphate, washed away as an "impurity" while cleaning "hard" phosphate rock during the manufacture of acidulated phosphoric fertilizers was, indeed, a prime resource for the biological farmer. Combined with poultry litter and high-calcium lime, and all under the watchful eye of Reams, the formerly disdained soft rock phosphate produced superb highly-mineralized citrus as well as other crops.

Reams was well aware that citrus crop quality was directly proportional to juice richness. His years of incessant laboratory experiments had proven, over and over, that the mineral content of a crop marched in lockstep to the "heaviness" of the juice it contained.

History does not record when Reams first realized that the concept applied to other crops than grapes and oranges. Nor does history record when he first picked up a refractometer and said, "I wonder?" Did someone else say, " Dr. Reams, take a look at this," or did it come to him as inspiration?

Whatever the answer to those questions, it is known that he created a bombshell in the early 1970’s when he, refractometer in hand, walked into the office of ACRES USA and placed a simple chart on the editor's desk. That chart correlated brix numbers with four general quality levels for most fruits and vegetables. Copied innumerous times, it has made its way around the world over and over.



What proof shows that higher brix means higher quality?

Centuries of wine making and work with other fruits and vegetables always show direct relations between high Brix and high quality, expressed most simply and directly as superior taste. The process is somewhat altered for the gardener or farmer in that they test the leaf of the growing plant much earlier and are therefore afforded the opportunity to correct soil deficiencies before the crop matures. The gardener or farmer also benefits in that they soon learn that any crop with 12 or better leaf Brix will not be bothered by insect pests.

BRIX measures the percent solids (TSS) in a given weight of plant juice‚ nothing more‚ nothing less.
BRIX is often expressed as the percentage of sucrose. However, the "sucrose" can vary widely.
BRIX is actually a sum of the pounds of sucrose, fructose, vitamins, minerals, amino acids, proteins, hormones, and other solids in one hundred pounds of plant juice.
BRIX varies directly with plant QUALITY. For instance, a poor, sour tasting grape from worn-out land can test 8 or less BRIX. On the other hand, a full flavored, delicious grape, grown on rich, fertile soil can test 24 or better BRIX.



Remember that sugar is only one of the components of brix. Also remember that many other substances can falsely indicate "brix" readings: rubbing alcohol, whiskey, vinegar, or wine (although those readings are valid in their own right). Interestingly, cooking oil, molasses, syrup, and other thick liquids require a refractometer calibrated to read 30-90 brix. Honey is checked with a refractometer calibrated to measure the water in it instead of solids in water.

Originally Posted by rrog

As Seamaiden said, this is not technically correct

Yeah and Weird posted some good info and basically had it correct. Brix really measure total solids of which sugar is a main component. When look at non-digital type meters what you want to see is a more diffused reading which indicates a broader spectrum of compounds.

If you really want to get into this get a full compliment of sap meters for testing pH, EC, Na, NO3 and K. It's been awhile since doing all the research and pretty sure those are what you can get. Say you are starting to see increasing levels of Na in the sap then you're sacrificing things such as Ca and Mg. I think this is more important in soil situations and helps monitor things such as the base saturation rate. In this case sodium is basically displacing Ca and Mg. Tom Hill talked about this a bit. There is a bacteria product that has been shown to convert sodium to potassium and Tainio Technologies carries that.

Monitoring pH is more important, I believe, to monitor a trend. When you see pH above or below certain levels you will see either pest or disease issues. So here you will see the pH shifting before problems start to visibly show up.

I thought it was when brix gets above 12 is when you start to have much better pest and disease resistance. Supposedly sap sucking insects stay away from high brix plants. Insects in general stay away.

Veg N Out here started to work with brix and stuff and said when brix gets above a certain level canna plants takes on a blue hue. Seems he was making good headway collecting info. Nomaad had a brix tester last year for awhile then lent it to a friend and didn't get it back. Don't think he got a lot of info though.

I do believe that higher brix levels influence finished herb quality just like it does with fruits and veggies. Someone posted higher brix means higher levels of secondary metabolites or something. I bet if you ran 2 plants side-by-side and one was really low brix and the other very high you would see a difference in the bud quality and even things like resin production.

Bob Pike at Pike Agri Labs knows his stuff and studied under Carey Reams. A friend sent some regular wild herb plant material to him for a full analysis and quite revealing. The stuff was crazy high in K. What you see with modern grown plants is typically higher levels of NO3 than K and that's when you also have disease issues. In nature, from what I remember, K is always higher. Lots of good info about brix and sap testing if you scour the net. I do believe that those growers that use sap testing info will have the edge down the road. I mean fruit and veggie growers have been doing this for years and canna growers are supposed to be leading edge lol. Have heard about some growers really getting into sap testing. I worked with an agricultural consultant who's been using sap testing for a few years and very interesting. It's an integral part of his consulting service.

There's a good book called Ask the Plant which goes in petiole testing. There's a CD that Acres puts out of a talk that Bruce Tainio did about sap stuff that was helpful.

[EclipseFour20]

And...an interesting procedure for complete plant testing...including brix, ph & ec.
https://www.pikeagri.com/images/PDFs/...structions.pdf

You can also get chlorophyll testers but those things are stupid expensive compared to sap testers.

[ShroomDr]

i own one, and they are EXTREMELY overrated for MJ.

Its hard to get a 'full drop' of MJ fluid. I could probably do it if i hacked a large enough piece off, but a large fan leave will (generally) not suffice.

I even bought a garlic press to fold the leaf up in, and juice, its just not worth the trouble.

^ I was waiting for someone to come by and drop some truth.

I just couldn't see how it would be possible to squeeze enough juice from your plant without having to take too much off.

Then having to hack a new piece off each week to test the brix.

I think if you know your plants well enough, know your soil well enough you should be able to tell if your plants are operating at max potential.

Refractometer to me is for the farmer growing acres of veggies and is unsure about the exact mineral content of his fields or portions of his fields. If you make your own soil you should already know if your mineral content is up to snuff. And even then it can take a few years of soil regeneration to get that optimal array of broken down minerals in your soil. Minerals don't break down over night so if you are using your soil just once this whole concept is pointless.'

[analogue]

refractometer demonstration

Also a useful accessory will be a garlic press to squeeze the juice out of your leaves. Only takes a few leaves, less than 5 or 6.

Collect your leaves to test at the end of the day during lights on. Highest Brix readings at that time. During lights off, Brix levels go down in the leaves as sugars get transported to the roots.

I use a 30$ model, looks just like all the other ones... tests from 0 - 32% Brix. You don't need higher than that when testing cannabis. You'll probably test out in the low teens.

[rrog]

I'm also unsure of why we MJ people would care, other than just curiosity. To get high Brix figures, you basically amend soil as we do already. Measuring the Brix doesn't change that at all

One more thing I can add about leaf testing is removing the mid rib. The chickweed that Bob Pike tested was lower in brix than he anticipated. His thought was it was difficult to remove the mid ribs as the leaves were very small thus influencing the final reading.

I think if you know your plants well enough, know your soil well enough you should be able to tell if your plants are operating at max potential.

Refractometer to me is for the farmer growing acres of veggies and is unsure about the exact mineral content of his fields or portions of his fields. If you make your own soil you should already know if your mineral content is up to snuff. And even then it can take a few years of soil regeneration to get that optimal array of broken down minerals in your soil. Minerals don't break down over night so if you are using your soil just once this whole concept is pointless.

I hear ya on the first paragraph but that's still guesswork. Do you ever at least have your soil tested to really know what you have? I don't see how it would take a few years to get the optimal mineral profile but that's just my opinion.

I can see for indoor growers with smaller plants doing this type of testing is probably not worthwhile. For large outdoor growers I think it's valuable. These guys are pushing things trying to maximize yields and monitoring plant health is important for disease/pest issues and still believe it helps quality. You are assuring your plants are performing at their peak. The top outdoor growers I know test their soil.

You can use sap testing to monitor things like nute uptake after watering/fertigation. Soil O2 levels drop after water then rise as the soil dries. With lower O2 levels you have lower nute uptake. If you adjust water/fertigation ORP levels you don't slow your plants down with that drop in O2 levels. I'm guessing you can figure out the optimum ORP value adjustment by watching nute uptake. Tom Hill talked about adjusting ORP levels and assumed he's using sap testing to figure out the optimal level but that is a guess on my part.

All the little 'hiccups' you have through the growing season add up in the end. You can watch what's going on with the sap.

As for the bolded part not really. Farmers who are doing sap testing are already doing soil testing so know what's going on there. If doing sap testing they're usually doing plant tissue testing at a lab also and getting valuable mineral info from that. They're using sap testing to monitor their program and only an aspect of what they're doing and part of the whole puzzle.

I'm also unsure of why we MJ people would care, other than just curiosity. To get high Brix figures, you basically amend soil as we do already. Measuring the Brix doesn't change that at all

I can see that people would care if they are interested in understanding exactly what's going on better. Basic science takes out guesswork. For me the information would help you grow the optimal plants.

[rrog]

Originally Posted by Nondual

I can see that people would care if they are interested in understanding exactly what's going on better. Basic science takes out guesswork. For me the information would help you grow the optimal plants.

I think a soil analysis would be more helpful. If there's some soil deficiency, a soil test would tell everything very specifically. Measuring Brix seems to be an art in and of itself. Measurements change during the day due to transpiration, change after watering, after top dressing, etc.

We know that starting with great soil, amending properly as we go, produces the best product. Not sure I need a meter to measure brix to confirm this.