Yet another niter / brix question

[Lloyd Miller]

I apologize in advance for rambling!
I've been backyard sugaring for many years not paying much attention to brix on my finished product (looking back most batches were "light" syrup but tasted great). After reading posts on this site for a while I decided to get "scientific" and added pre-filters to either my wool or orlon cones and measuring brix. This year I have finished (3.5) gallons of syrup. I have noticed that if I finish to 7 degrees above BP of H20 (as measured on the day I finish) I get "light" syrup (64-65 brix) but if I go to 8 degrees above I get "heavy" syrup (68-70 brix). My thermometer does not have tenths of degrees (although I have ordered one). The light syrup is clear with no niter. The heavy syrup has niter. I usually filter when I reach temperature but tried filtering at 2-3 degrees shy of temperature and reheat to temp without further filtering as suggested by someone on this site. I bottle in mason jars immediately after filtering. Either way I get the same result.
Does anyone have any idea how I can get to 66-67 brix and not get precipitate?
I know for home use this is academic but being of the scientific mind it bugs me!

[dbcriss]

I'd go with a long stem syrup hydrometer for $15 and the ss hydrometer cup, probably $10. The hydrometer is very accurate and consistent.

[Adammp1]

66-67 Brix seems high for finished syrup. I never go higher than 59-60 Brix. You can always "fix" heavy syrup by adding sap. I would highly recommend buying a syrup hydrometer and test cup. Good luck!

[Moser's Maple]

Adammp1,
ummmmm
international standard for maple syrup is 66 brix
vermont standard is 67 brix
if you aren't at least 66 brix........then by definition you don't have syrup.
sorry if you didn't realize this, but this is the density that is considered maple syrup
Jake

[Adammp1]

Jake: yes 66-67 brix at 60degress. I thought the question was refering to hot syrup. 59-60 brix at211 degrees f. sorry I should hve been more specific

[Lloyd Miller]

Thank you everyone for your help and ideas.
First I should have specified I measured the Brix at 60 degrees. I have a hygrometer and refractometer and they agree in all instances so far.
I have since acquired a thermometer that reads in tenths of degrees. I have checked one thermometer against the other. The one that reads whole numbers jumps to the next higher temp when the one reading tenths reaches the the 1/2 degree mark. Today I finished a batch using both thermometers and needed to go to 220.7 degrees (7.2 degrees above the BP of H2O). The whole number thermometer reached 220 at the same time that the other reached 219.5. I finished at 220.6 degrees and the Brix is 67 at 70 degrees (room temp). using the whole number thermometer I believe I was stopping 1 degree below what I should have.

[smokeyamber]

Ok , the niter thing is not the brix, but the temp, as the syrup cools from the top temp the niter precipitates out. So I think the solution is to let if cool to allow the precip and then reheat to around 190 deg and re-filter to remove the niter. My understanding is once you get to boiling again more niter will precip out on cooling hence only going to 190 to get the syrup nice and hot for filtering/bottling. Can a experienced sugarer confirm this step ? The filter on drawoff will definitely help things and I would do it as well.