CDL Vacuum Filter

I have been using CDL's 12" Vacuum Filter since 2020.  To say it is an easy piece of equipment to master would be a BIG FAT LIE!  It has been a struggle, but it was well worth it in the end.  Here are some tips and tricks I have learned the hard way, and hopefully, you will find them useful.

1.  Remove the cheap tube gasket that it comes with.  In most cases, it has been glued in place, and there is a small gap where it does not come together.  Instead, use a two-part gasket.  Cut two 1" wide 12" rings out of silicone baking mats first.  Second, order a silicone gasket ring for pressure cookers (11.5" in diameter).  Together, these two will form an airtight seal, and even the smallest shop vacuum will create 5hg or more of a vacuum.

2.  However you connect your vacuum to the unit make sure you use Teflon tape and tighten completely.  

3.  Draw off your syrup and keep above 200 degrees.  Wet 5-7 paper prefilters to the top of your filter and clamp down.  I batch boil which increases the amount of niter/sugar sand making normal gravity filtering very difficult and wasteful.  My process is to add 1 cup of diatomaceous earth for every gallon of syrup.  Whisk it in thoroughly.   Next start pouring syrup into the top of the filter but only a little past the halfway point.  Turn on the vacuum and watch it go down.  If it goes down relatively quickly (under 2 minutes) you have enough diatomaceous earth.  If it takes 5 minutes or does not completely go through you need to add another 1/2 cup of diatomaceous earth for each remaining gallon.  Continue this process until you have filtered all your syrup.

4.  Next draw your filtered syrup back into a pot and put on the stove.  Bring up to 211 degrees and test density with hydrometer.  I normally have to add permeate or distilled water.  Once you have it perfect - 67 brix you want to add 1/2 cup of diatomaceous earth for each gallon.  

5.  This time you want to add the heavy orlon disc and 5-7 paper filters to the top of the filter.  Make sure you wet them prior to filtering.

6.  Pour your syrup in above 200 degrees and this time you can fill up to 1" from the top.  The syrup will go through very quickly.  Filtering a second time makes your syrup come out crystal clear and is must if packaging in glass.

7.  After each pour remove the top layer prefilter and continue the process until you have filtered all your syrup.