Hard boiled eggs in the shell keep well for at least a 3 days outside of the fridge, I've eaten them after easter this far removed from when they were boiled for many years with no ill effects...once they are boiled for a few minutes, all offending critters are effectively killed and the interior of the egg is inaccessible to microorganisms.
My recipe for a perfect hardboiled egg:
1. Add eggs carefully in single layer (pricking small hole in top is optional) to the cold water.
2. Cover all eggs with water by at least 1"
3. watch pot carefully, when the bubbles just begin to pop (around 200-205 F), remove the pot from the fire
4. cover and wait 17 minutes. Drain.
5. Put eggs in ice cold water straight out of the pot
Eggs will come out perfectly hard boiled everytime with this method. Yolks are nice and yellow (not green) and the eggs peel easily. Here's a tip to make sure the eggs peel easily: use old eggs! A week or so after you buy them is the perfect time to consider hard boiling.
If you're using new eggs, your eggs will look pretty bad after peeling (although it won't matter so much for a scotch egg!
Here is the ultimate egg post:
[url]
http://forums.egullet.org/index.php?showtopic=85222[/url]
Scroll down to "all about eggs"[url]
http://forums.egullet.org/index.php?showtopic=36902[/url]
Info on "hard cooking" eggs
If you've never been to the egullet before, it's quite a site for cooking enthusiasts!