A possible drawback to One Pot Brewing – using one vessel for the entire brewing process – is that you’re “one pot” will be tied up. You cannot brew several batches at once, or two batches in two days. That’s not entirely true and misses the point of the method. Why would you want to brew two batches in one day? –because you haven’t brewed in so long? Simply put, you will most definitely make more beer with One Pot Brewing because brewing is easier, faster, less cleanup, and more enjoyable.
Secondly, fermentation doesn’t take that long. 10 days tops? (I just brewed a Pilsner that took 10 days grain to glass). Let’s say 13 days at the most, including cold crashing. In those 10 days, I begin planning my next batch, looking at my recipes, and getting the ingredients ready. Honestly, how often does a person want to brew? More than twice a month? It’s all quite lean and has a nice flow. Homebrewers tend to brew in fits and starts, and it’s because the process takes a ton of work. One Pot Brewing is more like cooking – a constant thing. This is why I brew more than most homebrewers, why my fermentation chamber is rarely empty.
However, if you really want to brew a lot, you simply ferment in a plastic bottling bucket (which also comes with a spigot attached at the right spot, above the trub line). They are very cheap. I’ve done that a few times and it works just the same. It’s simply another vessel to clean after brewday. It’s a great feeling, however, to not have anything to clean when brewing is over – not even a pot with crap in it.