Is fermenting not a winter activity?

Last Sunday I bought a gallon of apple cider. After drinking a few glasses of it (over the course of two days) I decided that it was no where as good as I remembered apple cider being. It was from a farm, and it looked nice and dark, but it just tasted like very sweet apple juice --- no kick. So I decided to leave it out near the window sill (where it was still pretty cold) for a few days. Forgetting about it until Friday, I was very surprised that when I went to open up the plastic jug, I heard a loud hiss of air (CO2 more likely). When I pour the cider, it bubbled and when I tasted it, my taste buds jumped for joy. Just a few days of fermentation (completely uncontrolled) had given me a tangy, slightly hard, cider. The overwhelming sweetness was gone, as the fermentation had surely consumed much of the excess sugar. I think I remember the cider at the right time. Had I left it much longer, it may have become a little too strong, though who knows.
Inspired by my inadvertent success with fermenting cider, I decided to reattempt Dosa making. Months ago I had some difficulty getting the right consistency and right texture to my Dosas. I repeated the same recipe, mixing Urad dal, a little Chana dal, some short grained rice (sushi rice this time) and some Methi or Fenugreek seeds (which made headline recently as being the smell behind a chemical/gas scare in New York a few years ago). I soaked these in water overnight and then blended them to a course pulp in the morning. In the evening I tried to make a Dosa. It came out rather plain and lacked a crunchy texture and contained too much of the original courseness of the ingredients. This evening, after another day of fermentation, I approached the bowl of Dosa batter. The change was marked. It had begun to foam and the course grains had somehow been consumed and changed by the fermentation. The fermentation (though slowed from the cold) had certainly transformed my mixture. A cast iron pan and a little oil quickly yielded my first very successful Dosa. It was crispy but not grainy and the bottom was nicely browned, though the top stayed a little spongy. Still not as good as the Dosa cart, but I have enough batter to experiment for another few days. Who knows, maybe in another day or two, the batter will have evolved further. Though, I had refrigerated the batter since there is a lot left.