Never try to filter cold syrup, it must always be filtered hot. This is how I do it and never have an issue, I have a 7" 5 plate (5 hollow plates plus waffle plates, 10 individual filter papers):
I heat the syrup to 205-210F, then I draw 3-4 gal of hot syrup into my mixing pot. I add 1.5-2 cups DE, mix and then pump it thru the filter press pump and bypass it back to the mixing pot for 20-30 seconds. That helps ensure complete mixing. I then open the filter ball valve and close the bypass valve, sending the filtered syrup back to the mixing pot. I watch the syrup as it flows out of the hose. When it starts to "sparkle" I open the by pass valve, close the filter valve and then hook the 180 bend that discharges filtered syrup over the top edge of the bottler (or into a barrel). When that batch is finished I draw more hot syrup into the mixing pot. In my case that pot holds almost 7 gal, I fill it to 5-6 gal. I then add about 1.25 cups DE, stir, run thru pump and back to the mix pot for about 20-30 seconds again, then I open the filter valve and close the bypass valve. No need to do the extra step because the filter papers are already coated with DE and the filtered syrup discharge is already sending the syrup to the bottler (or a barrel). If you have more syrup to filter, repeat until finished or whatever you are sending the syrup to is full. My bottler is a water jacketed bottler, and before I start sending syrup to it, I turn it on and have it hot. The filtering will cool off the syrup, but my bottler brings it back up to 185-187F. I'm then ready to bottle, after I verify density using my Murphy Cup and Hydrometer, I then grade it, record the grade, mark the sample couvette (I use a Hanna Checker which gives the % of light passing thru the test vial called a couvette) then I proceed to bottle or jug the syrup. Always bottle at least 180F but not over 190F. Having filtered it much hotter you will not get more niter forming.
However, when I repack syrup that was filtered and bulk packed (into a barrel or other bulk container) I do it a little differently. I heat it to 175-180, then filter as before, but after the filter papers are coated, I only add about 3/4 cup DE on each additional batch. Not heating it to the 205-210 helps keep the grade, the more you heat it the darker it will get and on repack syrup I want to get the grade it was when packed in bulk. That usually works, but if it was on the darker side of whatever grade it was when bulk packed, it may end up on the light side of the next darker grade.
Last edited by maple flats; 03-05-2022 at 09:36 AM.
Dave Klish, I recently ordered a 2x6 wood fired evaporator from A&A Sheet Metal which I will be converting to oil fired
Now have solar, 2x6 finish pan, 5 bank 7x7 filter press, large water jacketed bottler, and tankless water heater.
Recently bought another Gingerich RO, this one was a 125, but a second membrane was added thus is a 250, like I had.
After running a 2x3, a 2x6, 3x8 tapping from 79 taps up to 1320 all woodfired, now I'm going to a 2x6 oil fired and a 200-425 taps.