Here’s part two of the fresh vs. dried lemon balm experiment. 
Both tinctures started with the same 80‑proof vodka (40% alcohol). After tincturing the lemon balm, I used a hydrometer to check the alcohol content. For the dried lemon balm tincture the hydrometer still reads 80 proof / 40% ABV; which is exactly what we’d expect when there’s essentially no extra water coming from the plant. The fresh lemon balm tincture, though, now reads about 70 proof / 35% ABV, because the water inside the fresh leaves diluted the alcohol. Fresh plants are often around 70–80% water, and that water dilutes your menstruum.
Why does this matter? For long‑term stability (and to avoid fermentation or spoilage), most herbalists aim for a final alcohol percentage of at least ~30% in an alcohol tincture. That means if you’re using very juicy fresh herbs, starting with low‑proof alcohol (like 60 proof / 30%) can drop you below that preservation zone once the water in the plant joins the tincture. Dry herbs are more predictable in this way, but fresh herbs really are not.
So if you love working with fresh, aromatic plants like lemon balm, think in terms of higher‑proof alcohol to make room for that built‑in water...or reserve the lower‑proof spirits for dried material. Same plant, different math. This is the artistic side of herbal works; not just what you extract, but also the solvent balance that keeps your medicine stable over time.
Buying a hydrometer is a great investment for testing your final formulas. There are two kinds. A mead/beer/wine hydrometer only goes up to about 20% alcohol and does not show proof. "Proof" is only used to measure distilled alcohol. So, for tinctures you will need a hydrometer for distilled alcohol that goes up to 200 proof. Comment below if you've tried this!
