Swamp cooler temperature questions

[richfei]

I have an American pale ale which has been fermenting in a 6 gallon bucket inside a Homz tub acting as a swamp cooler. It's the first time I've done this. In the past I would just leave the bucket alone in a closet but the temperature fluctuated wildly and sometimes reached 80-84, which is something I wanted to avoid this time.

The tub is filled with water almost to the brim. The bucket is tall so the water is below the level of the wort. There are wet towels draped over the top of the bucket, which I don't swap out. Fermentation has been active for 3 days but now there is no longer any active airlock activity.

Ambient room temperature is around 80. I pitched at 68 with Safale US-05 and left 4 bottles of iced water in there during the day and overnight. Temperature of the water in the cooler during the day is 64-68. It's about 69 when I wake up. After I switch out the bottles in the morning the temperature goes back down to around 64-65 then settles to 66-68 until I swap out the bottles again

Is it necessary to keep this range between 64-68 until bottling ?

Should I be shooting to keep an even narrower range i.e 60-62 or lower maximum temperature i.e 64 ?

Should I be swapping out the towels everyday also ?

 

[abrix]

With active fermentation being finished, I would let the temperature rise to 68 or even into the mid-70s to make sure the yeast gets done working. If you drop the temp on it too soon, the yeast might quit before they finish cleaning up the diacetyl, etc.

After a couple days warmer, then I would aim to drop it to 60 or lower (whatever you can manage with your setup) for a day or two before bottling.