L-Valine

Valine is by a wide margin the most soluble of the three BCAAs — 88.5 g/L in water at 25 °C against isoleucine's 41.2 and leucine's 24.3. In a 2:1:1 blend it is never the ingredient that limits your concentration, which is worth knowing when you are diagnosing a hazy BCAA drink: the problem is leucine first, isoleucine second, and essentially never valine.

Its solubility is also the flattest with temperature of the three — 83.4 g/L at 0 °C to 102.4 g/L at 65 °C, only about a 23% swing. That makes valine the most predictable BCAA across a cold chain, whereas isoleucine roughly doubles over the same kind of range.

Valine sublimes without melting at ordinary heating rates and decomposes near 298-315 °C in a closed capillary. Sublimation matters for vacuum drying and lyophilisation, where you can lose material to the condenser rather than to degradation.

It is insoluble in common neutral solvents and only very slightly soluble in alcohol, so like the other BCAAs it is aqueous and dry-blend only.

Valine and leucine share the branched-chain pattern but differ in molecular weight (117.15 versus 131.17), so a 2:1:1 blend by weight is not a 2:1:1 blend by moles. If you are specifying a ratio, state whether it is w/w — the industry convention is by weight, but say so.

Reported crystal density is 1.23 g/cm3 at 25 °C. As with the other amino acids in the range, ask for bulk and tapped density separately if you scoop-fill; the crystal figure will overstate what fits in a scoop.