DA http://jazzbarisax.com/articles/reeds/

“… There are two approaches to preventing warping, the first is to allow it to dry slowly and evenly regardless of environment and condition. The second is to try to control the humidity. In both cases having a case or flat surface as opposed to using the plastic reed protectors the reeds come in is recommended.

Approach 1: Let the reed dry evenly, and slowly!

The first approach takes into consideration why reeds drying out causes warping. It is not simply the drying process, but the fact that the reed does not dry evenly from top to bottom! A lot of saxophonists use reed cases with glass – assuming placing the reed on a completely flat surface like glass will allow them to dry flat and not warp. This may infact be encouraging warping, as the bottom of the reed on the glass surface will retain moisture, while the top of the reed will begin to dry. This creates a water differential that causes warping as different cells in the organic cane are forced to stretch or contract depending on their water contents. Cases that utilize this approach will have ridges under the bottom/table of the reed to allow airflow all around the reed and promote even drying. The cases will also have carefully placed ventilation holes to allow for even and gradual changes in humidity.

Approach 2: Don’t let the reed dry. (Danger!)

The other approach to controlling a reed and preventing damage and warping is to control the humidity of the reeds. Recently, several companies have released special plastic “pouches” that control the humidity inside – using pouches originally designed to control humidity for tobacco. Vandoren ensures the consistency of their reeds sealing their reeds individually at the factory to have greater control over the humidity before the reeds reach the players. Music store or warehouse humidity and storage conditions vary greatly.

Some saxophonists turn to keeping their reeds constantly wet, never allowing them to dry out at all, and thereby never allowing them to warp. This is achieved by having a bottle or some sort of container filled with water/liquid that the reeds are stored in. There are several potential problems with this approach! First of all there is a health risk. Keeping organic reeds submerged in water for long periods is basically encouraging mold and bacteria to grow. There have been several cases of saxophonists developing infected tonsils from reeds that were unclean. If you do choose to keep your reeds always moist you can prevent anything from growing on your reeds by adding a small amount of alcohol based mouthwash (Listerine) to the water you store your reeds in. The alcohol in the mouthwash will keep the reeds sterile, and the minty-ness will probably improve the reed’s taste. On a side note, Do not indulge in flavored reeds! These are really susceptible to having unpleasant things grow on them …”.