Not much. If it tastes too sour than don''t drink it.
Yogurt usually lasts longer in the fridge. But yogurt would last between 1-2 weeks.(According to most expiry dates)
Milk can last unrefrigerated for about 2 hours before it spoils.
That would depend on the quality of the yogurt, how long it has been unrefrigerated and how much it might have been mishandled before. When you realize that yogurt is the result of controlled spoilage and is chock full of desired bacteria, it would make sense that not much other bacteria are going to be growing in it - at least not for very short time frames of temperature abuse. "No more than 2 hours" is the standard advice for unrefrigerated potentially hazardous food. I don't refrigerate my yogurt on the trip home from the store nor on my commute to work. Putting yogurt through temperature abuse can reduce the populations of the good culture and can eventually permit the growth of yeasts, molds and other acid-tolerant bacteria. If the store or delivery service has the yogurt unrefrigerated for an unacceptable length of time, I suggest you talk to them. If you do not get a good response, talk to your local health department. After all, you are buying yogurt for a reason. You should get it at its best quality.
for 2 hours
Unrefrigerated milk typically lasts for about two hours before it spoils.
that happened to me... the pharmacist told me that if it has been unrefrigerated for more than 12 hours, it has lost effectiveness and a new prescription is needed. Unrefrigerated for less than 12 hours he said would still be OK.
They are considered safe, unrefrigerated, after no more than 2 hours. But this must depend on what the eggs are made of. A chocolate egg will be safe unrefrigerated for years.
4-hours is not a problem.
several hours
Refrigerated food can only go unrefrigerated for four hours.
That depends how long they have been unrefrigerated. If they've been sitting out for more than 2 hours, I wouldn't use them.
Two hours.