DME too quickly. Here is the deal with the energy schemes regarding water with minerals in it such as your tap, and "filtered" water clean of such ions. Salt is a good analogy. If you add salt at the beginning when you are trying to boil water, you will actually increase the time it takes to boil it, however it will boil at a hotter temperature (which is why your pasta cooks faster). By using filtered water from a bottle the water will boil faster but at a lower temperature. This has to do with raising the vapor pressure of the surface of the liquid when adding a salt or mineral (raise the surface vapor pressure, raise the amount of energy needed to boil). All in all, i doubt it made a difference at all under your circumstances and its probably due to adding too much DME too quickly, I have to watch the pot so very closely for the first 5 min after adding dry sugars. Hopefully that made sense, some of that may need to be corrected.