I've been brewing a bunch of 1-gallon batches of cider in clear glass jugs, as well as a couple other batches of wine and mead on the side, and I've become quite confused about how the final clarity of the brew comes to be. So I'm going to share what I know, and then I'm hoping some of you will come through and add to, qualify, or maybe even straight up refute what I say here.
That being said, lets talk Clarity:
Here's what I know/suspect:
While fermentation is going on, so is flocculation, the process whereby suspended solids settle out of the must.
The yeast itself is a prominent suspended solid. This is why the must often becomes cloudier as it ferments.
The amount of flocculation that occurs is affected by several factors. Notably, the yeast itself has a variable tendency to flocculate (ultimately settle out of the must).
Pectin, a carbohydrate, is another prominent suspended (or is it dissolved?) solid. Pectic Enzyme (one of several enyzmes known as a pectinase) breaks down pectin, which is then allowed to flocculate.
That being said, I notice a great deal of variability in the final clarities of my brews, even when I prepare them under seemingly identical conditions. Sometimes, the pectic enzyme seems to make the brew sparkling clear, other times it seems to have little effect. The white wine that I am currently brewing is about as close to opaque as I have seen, and it started off clearer than most of my ciders and with twice as much pectic enzyme.
A couple key questions:
Flocculation occurs, but does precipitation (the process whereby dissolved, as opposed to suspended, solids settle out) also occur? What are the determining factors that cause or do not cause precipitation?
What is the full spectrum of suspended solids that cause brew to cloud? What different factors cause them to settle out?
Various brew additives (yeast nutrient?) bind to elements of the must that are considered unhealthy for the yeast, and cause them to settle out of the brew. Does this contribute noticeably to flocculation or overall clarity?
Thank you all so much for your input!