None that I can think of unless there are chemicals in your water donated by your water system provider. I usually set up all the materials before I plug in the pumps, but I also squeeze the bags holding the amendments and compost during brewing as well.

One of the benefits of using air pumps is that the bubbles will dislodge the fungi within the compost, the bacteria will multiply on their own. With a short brewing time of 24 hours or less one is assured of aerobic compost tea that should be maximum population of microbes limits. IMO, the acids and pre-digestive juices are as important as the microbes, so brewing longer seems like a waste to me. I trust this helps in some small way...

Blutranes

Thank you blutranes. Your answer was helpful, but raised another question for me.

It has always been my practice to steep compost tea for a day or two before adding molasses. For the life of me, I can't remember why--that's just how I do it.

Would there be any advantage to putting in the molasses at the same time as the compost tea bag? I make tea in a 32 gallon plastic garbage can.

"Would there be any advantage to putting in the molasses at the same time as the compost tea bag?"

Yes, less brewing time to get a good tea to use. Waiting more than 24 hours can set up the dynamic for the tea to become anaerobic, which is not good if using the tea for a foliar spray IMO. A fresh, sweet smelling compost tea gives me the results I have come to expect and enjoy watching as the leaves and stalks of my plants open up as only compost tea will give. I really don't feel stronger tea is a good thing Maupin, I have found weaker, diluted solutions work better in most cases, and allow for a better spread of the tea while spraying (more bang for the buck).

Again, this is my experience, and I will admit I have gotten almost as good results from just dumping compost in a drum (I make 55-gallons at a time), stirring it, waiting a couple hours and then using the tea. I guess it boils down to weather one is willing to go through the trouble of making aerobic tea; for me there is no trouble, I love the entire process....

Blutranes