As a note, I can’t claim credit for any of this. This section is the work of a couple of users on the StraightBourbon.com website, mainly Josh, Oscar and a guy named Taanstafl2 – and see the note just below. But it’s too important to leave out even if it’s a bit more advanced.
I use the format: Distillery Brand Name (%corn/%rye or wheat/%malted barley). This is a breakdown of "macro" distillers. Wondering what the different char levels look like? This is a good illustration.