How does one go about storing phalaris leaves? Ive heard freezing them in alcohol will preserve the alkaloids, but wouldnt the alcohol pull out some of the dmt you want?

Would just freezing them be adequate for a couple weeks storage?

If you cannot juice and extract/brew the leaves right after harvesting, plainly freeze them in an airtight container. That will slow down enzymatic activity and reasonably preserve the alkaloid profile. Unless you can use flash-freezing, I'm not sure if preserving grass this way for a long time would diminish returns, but for a couple weeks it should be okay.

I can say for sure that the dried grass does still contain dmt. It would be most interesting to see some analysis on fresh vs dried grass to see if there really is a difference in alkaloid content.