I brewed my second batch this last weekend. The bubble action of this batch is totally different from the first batch. The first batch had an OG of 1.071 and used Safale-04 yeast. This batch bubbled vigorously and for only a few days. The second had an OG of 1.052 and used Nottingham yeast. This second batch hasn't bubbled as vigorously but is still going at it. Is this because of the yeast, because they have different OGs, or because it was sunny this weekend and snowing the first weekend?