| 🔬 Adulterant | ⚗️ Effect on Recrystallization | 🧊 Appearance When Cooled |
| 💎 MSM (Methylsulfonylmethane) | Delays or prevents; forms oily mix that resists solidifying | Clear or cloudy oil that stays liquid |
| 💧 Water (moisture contamination) | Slows or halts; may result in syrupy consistency | Syrupy or tacky layer that dries slowly |
| 🧪 Acetone/Ether (solvent residues) | MA remains dissolved; needs full evaporation to crystallize | Oil with slow evaporation and delayed solidifying |
| ☕ Caffeine | Hygroscopic; traps moisture and delays recrystallization | Sticky mess; may remain brownish or clumpy |
| 🌿 Ephedrine/Pseudoephedrine | May recrystallize but introduces artifacts or stickiness | Partial recrystallization with clouding |
| ⚖️ dl-Methamphetamine (racemate) | Slow, uneven crystal formation; may stay waxy or oily | White-yellow wax or smeared residue |
| 🍬 Sugars (e.g., glucose, sucrose) | Sticky or gooey residue; often caramelizes if heated | Burnt sugar smell; amber droplets |
| 🥄 Baking soda / Soda ash | Forms cloudy or chalky paste; rarely crystallizes | No crystals, opaque mass |
| 💊 Vitamin B powders (e.g., B1, B6) | Creates colored powdery mix; does not recrystallize | Chalky or powdery residue |
| 🪨 Talc / Inert fillers | Remains gritty or powdery; does not form crystals | Dry but gritty and non-reactive |