I'd toss them.

They'll undergo a bit of hydration while sitting on the shelf, it'll reduce the quality of the product should you choose to use it. Weaker bond, etc.

Spend the $9 for a small box of fresh grout and the $15 for a bag of modified thinset. Easy choice.

Thanks. I would hate to do a couple hours work and have it fail again, so will follow your advice. It was tempting, since I have so much left.

As cheap as it is, get rid of it. About a year is the maximum in a climate-controlled environment. Laticrete might be a bit better as their stuff is vacuum sealed.

Even Vacuum sealed. The shelf life is 6 months from the date of manufacture, as opposed to the date you buy it.

Thanks. I get the message.
Would this rule of thumb also apply to general mortar used for brick work? such as Type N mortar? or concrete mix in paper bags?