remove astringency, bleach in water
醂 centers on treating something to remove harshness or unwanted qualities: removing astringency from food or bleaching something in water to purify it.
醂 combines 酉 (wine jar, related to fermentation or liquid) with 林, which likely contributes the sound. The exact historical development is uncertain, but the character is associated with treating or soaking in liquid.
The wine jar 酉 on the left holds a liquid, and the forest 林 on the right suggests something being soaked or treated. Picture soaking astringent fruit in a jar of water among the trees to remove its harsh taste.
For ラン, imagine running water through a forest to bleach cloth: run -> ラン, and the water in the jar 酉 does the bleaching.