I've tried a few different fermentation temperature control systems. I recently did a detailed review on the BrewJacket Immersion Pro. It's not cheap, but the temperature control is awesome (stays within +/- 0.5 degrees of your set point). It's easy to get going, and its best feature is it's electro-thermal heat transfer engine. You don't have to mess around with pumping cold water, or shuttling frozen 2L bottles of ice. You set the temperature you want and then you can be gone on vacation, or just go about doing other things. I'm surprised there are no other competitors out on the market making use of this technology.
If you read the review and have any other questions about it, let me know.
http://www.homebrewfinds.com/2018/02/hands-on-review-brewjacket-immersion-pro.html
If you read the review and have any other questions about it, let me know.
http://www.homebrewfinds.com/2018/02/hands-on-review-brewjacket-immersion-pro.html