2018 Shelf-Life Study, 1 Year Later:
In February of 2018, I consulted an outside expert to assist with answering some questions to better understand the product life cycle of the Sunburst Ant Nectar formula, such as, but not limited to the root cause of product degradation, and possible ways to extend the life of the product.
The field expert advised that I conduct an experiment by placing bottles of Sunburst and exposed liquid in a test chamber filled with pure carbon dioxide gas (CO2). At the end of these tests, we came to the definitive conclusion that exposure to CO2 is the root cause of product degradation.
When CO2 contacts the liquid, a series of chemical reactions occur, both with the water and the stuff in the water, which effectively make the liquid less tasty and more susceptible to the growth of microorganisms. Therefore, if the product is exposed to very little air, such as in a sealed or tightly closed bottle, the quality should change very little over the course of the product life.
After 13 months of shelf life study, during which time the bottles were kept at room temperature, the contents of the bottles used in the study have changed very little. The pH, which is the #1 key metric for determining whether the product has been exposed to CO2 as released by either microorganisms or exposure to air, is virtually unchanged from what it was a year ago. This is in contrast to our gas chamber study, in which the control liquid that had direct contact with the pure CO2 gas experienced a nearly 99.985% decrease in [OH-] concentration within a few hours!
Because the buffer capacity of the liquid is one important factor that affects the rate of pH change, smaller volumes of the liquid will respond more quickly to pH decreases as a result of exposure to air. This is one reason why Sunburst is the most attractive to ants for the first few hours or days when it is freshly dispensed from the bottle.
What this all amounts to, is that for bottles which have been opened, but very little used, the product should remain fresh for an extremely long time—possibly years if there is no contamination. However, as the product is used and the liquid volume in the bottle decreases, the product quality will begin to degrade increasingly quickly.
The next step in my study will be to repeatedly open, dispense, and close the bottled product in order to simulate real-world use. We will record and graph the pH change over time to obtain a deeper understanding of what a user might expect from using the product at the rate we recommend, as referenced below. We expect this next phase of the study to last 6 to 12 months, and I'll keep you all updated on the results.
The current recommended useful life is 3+ months for small bottles, and 6+ months for large bottles, after opening and with regular use. This may be a conservative estimate, but I won't know until the conclusion of the study.
If anyone has any questions, don't hesitate to ask them here.
What size bottle should I choose?
While everyone will use the product differently, the following table may offer some general guidelines as to the use-capacity* of each bottle size.
* Use-capacity determined by offering small colonies either 0.5 or 1 ml of product every 3 days, and larger colonies 2 or 4 ml of product every 3 days.
Edited by drtrmiller, March 30 2019 - 4:46 PM.