My wheatgrass taste duller than usual

Hello, vibrant healthy people!

(i am a new member )

I recently bought my wheatgrass seeds and soil from a new supplier and for some reason It doesnt have that sweetness, Tang-kick like my other trays I been growing in previous months.
What is the possible reason, Is it the seeds, soil perhaps? If you have any knowledge how please describe fully

Also can someone tell me where can I find good quality topsoil, peatmoss and kelp from on a steady basis( I use to get from random places but I want steady supplier now)
Am I better off getting my soil and p moss from a town garden center than commercial places like home depot?

Thanks a million!!