Flavor Loss & Grain Salads - Advice?

Ahhhh, a simple solution. Thank you both.

I can't say I've had this problem but what you might consider is to set a partial batch of cooked, undressed grains aside. Hold them with a coating of olive oil and dry seasonings (herbs, salt and pepper) refrigerated and finish them with a freshly made dressing the next day.

some of the 'flavor' components in dressing may be volatile and tend to dissipate as soon as they leave the bottle. The chemical 'ethers' & 'esters' responsible for these flavors are alcohol soluble which explains why red wine tends to 'unlock' them as opposed to a water based solvent. (this is the same reason why wine is often added to tomatoes Adding water can simply never release these chemicals from the tomatoes). My tip would be to add the dressing as and when you eat the salad.