If you made a beracha on a food or drink item and you took a sampling of it, how much time must pass until the next sampling for you to be required to make an additional beracha?
It is an important question as there is a prohibition of bracha levatala and I also asked it.
Answer I was given is that if you originally had the intent to eat/drink over a prolonged period of time, you do not make a bracha again. For instance, if you drink something as you work/learn, the original blessing covers you for many hours as long as you are in the same place/under the same roof. This is especially the case if the/your normal practice is to eat/drink multiple times in the same place.
My rav says his rav would make one blessing for all the water he would drink over hours of study.
See here for some more details.
PS. Noticed by "coincidence" a while after writing that it had already been answered on MiYodeya here
PPS. Coincidence, MikReH in Hebrew = Rak Me Hashem :->