Before doing anything else, I'd remove the rubber boot at the drain entrance and inspect. Should yank right out....likely held only by indents. That's where crud likes to collect and ferment and can't get flushed out by the action further down.

Is your drain vented properly?

The best place to post is in the plumbing forum.

Post what garbage disposal you have too.

I had assumed, perhaps mistakenly, that the "smell" was fermenting/rotting food smell. That would indicate trouble localized to the unit and is why I suggested removing the boot and inspecting. If it's a sewer smell, that would be an entirely different issue.

Have you tried baking soda?

Is this perhaps an island sink? If so, then I'd suspect that your Studor vent is no longer working properly.

Thanks for the input so far.

No, it's not an island sink, yes, the drain is vented properly (to the best of my knowledge), yes, we've tried baking soda, and there's no plumbing issue anywhere in the house (we just had ALL the pipes replaced, including under the house, a few weeks ago).

Did the stench start at the same time that you had all the major plumbing work done?

Ditto Angie DIY.....is the smell new as of a few weeks ago?