How to go from very dark to lighter in evaporator?

[john henry]

I was making some light/medium syrup in my evaporator. At the end of the last run I collected @ 800 gallons of cloudy sap from 1 of my tanks. It made a good tasting very dark syrup. Now that I have Clear sap again I have a question. I have @ 2,000 gallons of cold/clear sap to run through the evaporator. Will I be able to eventually go lighter with this sap even though what is now in the evaporator made very dark? I realize the first 4 or 5 draws will be dark but will things start to lighten up on me? I have a 4 x 14 evaporator wood fired with a 10' drop flue pan. I plan to run the sap through the RO removing @ 75% of the water so I will likely have about 500 gallons of concentrate to run. I wouldn't mind draining the front pan and boiling it separate but to drain the whole evaporator would be a lot of sap to waste or boil in my finishing rig... Thanks for your help!

[Sugarmaker]

john,
Should go right back to light or at least amber.
Regards,
Chris

[john henry]

Chris, thanks for your time in replying to this, it was good news too!

[maple flats]

It will likely go lighter faster if you concentrate to 12 or 14% rather than 8%. I read something by Dr Tim a year or 2 ago when he answered a question for someone about whether an RO affected the grade. He said concentrating up to about 10% tends to make syrup slightly darker, but then as you concentrate to a higher % the syrup produced tends to lighten in color.

[john henry]

Maple Flats, thanks for your time and reply. I am sure your advice is correct but I might not be able to get that kind of concentration. I am only on a homebuilt RO and have never tried to go above 8%... I am running a 1 HP feed pump to a Procon 330GPH "high pressure pump" driven by a 1.5 HP motor. This feeds 3 4x40 membranes in series. I figured going above 8% might be to much for my setup? My evaporator also runs @ 160 to 190 gph so I need a decent amount of sap for a boil.

[maple flats]

If you can't get to much more than 8% it will still lighten from the very dark, it will just take longer. As you boil, keep the boil going as hard as you can by using well dried wood, split small, hold the loading door open as short a time as possible and add wood as soon as needed. You might find if you were adding every 8 minutes, try every 7, then every 6 to see if it makes the boil harder. The faster the boil the lighter the syrup (actually it is the less time any drop of syrup spends in the pan the lighter the syrup).

[ennismaple]

If you are getting clear, fresh sap you will definitely make lighter syrup as you push through the sweet in the pans. I've seen ours come back more than 25 points on the LT scale over the course of a boil, even when we last boiled the day prior.

One thing we've done in the past when we had a freeze up is take the old sweet that was making dark syrup out and put it in a drum so we can re-start the evaporator from scratch making extra light (Golden) syrup. Hold onto the "dark" sweet until later in the season and feed it back into the evaporator.

[DrTimPerkins]

It will likely go lighter faster if you concentrate to 12 or 14% rather than 8%. I read something by Dr Tim a year or 2 ago when he answered a question for someone about whether an RO affected the grade. He said concentrating up to about 10% tends to make syrup slightly darker, but then as you concentrate to a higher % the syrup produced tends to lighten in color.

That is correct.

[bill m]

At a talk given by Joel Boutin he said running a flue pan deep will make dark syrup and running it shallower will make lighter syrup. I haven't tried it yet but will be next week sometime.

[Russell Lampron]

It will likely go lighter faster if you concentrate to 12 or 14% rather than 8%. I read something by Dr Tim a year or 2 ago when he answered a question for someone about whether an RO affected the grade. He said concentrating up to about 10% tends to make syrup slightly darker, but then as you concentrate to a higher % the syrup produced tends to lighten in color.

From my own experience 12 to 14% is the sweet spot for making lighter syrup. When you go higher than that it starts to darken again.