Hello again,

This is a good question. Whether or not something can be safely stored at room temperature depends on several factors - these can include the acid level (pH), available water (water activity), and quality changes due to light or oxidation. The type of packaging used, the presence of oxygen in the package, and many other things will also impact the quality of your product long term.

For your tincture, the primary component that could make your product shelf stable (able to be stored at room temperature) would be to control the available water.  This is accomplished with the glycerin. High levels of glycerin (greater than 55% of the total volume or higher) will keep the available water of your tincture low enough (water activity <0.75) that it will not mold. If the glycerin content is lower than 55%, then it would likely mold.  If the glycerin content is too low (less than 25%), then there is enough water available that some of the bad bacteria (pathogens) could grow in your tincture (and it would likely mold).

From a chemical perspective, some of the beneficial components in your tincture will breakdown with light exposure, at higher temperature (room temp versus refrigerator), and over time. Therefore, the quality of your tincture would be the highest if you stored the tincture in a dark container and in the refrigerator.

For more info on the benefits and harms of elderberries, you may want to take a look at this article: https://www.sciencedirect.com/science/article/pii/S<personal data hidden>0247X

Hope this helps.

Joy