When you make your first batch of beer from a kit, you are starting out with out enough yeast to be efficient,  you have  no idea how old the hops you included in your brew are  or how they’ve been handled and controlling the temperature of fermentation is assumed and the results are okay, but not what they should be.

You want to WOW your friends, but they tell you it’s good, and grab for their old brand if it’s available for the next one.

If you’ve followed the instructions with your kit, youve got most of it right, but you are under pitching your yeast, and controlling the temperature of fermentation is critical to makng the beer your friends will ask for the second time.

Unfortunately, fermentation vessels with temperature controls for home brewers are so expensive we are forced to rely on salvaged refrigerators or freezers with purchased external controls.