Here is the official answer, based on USDA recommendations: Almond milk should not be consumed if it was left out for more than two hours. This applies to refrigerated almond milk or shelf-stable almond milk after it has been opened.25 Nov 2021
Is almond milk safe if left out overnight?
A word of warning: never leave almond milk out at room temperature overnight. If you do so by accident, don't even bother to check if it's still okay! Just throw it out right away.20 Feb 2021
Does almond milk go bad at room temperature?
Almond milk needs to be refrigerated once it's opened. If the almond milk hasn't been opened and it's of the shelf-stable variety it will usually be okay at room temperature for a few weeks. However, some types of almond milk need to be refrigerated even if unopened.