Black birch makes a flaky precipitate. Thursday (4-25-2024), I let some simmered 4% settle at room temp in a half gallon jar tilted 45 degrees. Next morning, the junk was stuck to the side walls. Most of my 12 V vacuum pumps vibrate a lot. That is something to try next.

25 years sorghum
20 years maple and other tree syrups
RO, freezer, electric skillet and vacuum pumps