Use only freshly bought eggs.
Never direct from the referigerator. Take it out from the fridge
and the night before.
Look at the type of egg. Big eggs, average egg, Seng Choon eggs,
Chews eggs. Pasar eggs, kampong chicken eggs. Not all eggs are the
same.
The water must boil until bubbling and then stop heating. Set
that as the standard. Then experiment with the timings and the type
of eggs. And remember the resuts. This egg, this timing, this
done.
If your egg still cold from the fridge, your results will not be
the same. Eggs not fresh, yuckky. Water less than 100° C will
affect the cooking and timing need to be adjusted.
Simpler just to the coffee stall and order one set.