How do you boil all of your concentrate

[Big Stoney]

We have just purchased an RO and have never used one before. I read that concentrate spoils much quicker than sap. How do you manage to boil all of your concentrate for the day? I will need to empty my evaporator everyday before I go home.

[maple flats]

No need or reason to remove the contents of your evaporator before you go home. You just need to keep boiling until all the concentrate is in the evaporator and has gotten to a full boil. To do this, if you burn wood, you need to know how much more evaporates after your last fueling. Have a sight level tube on the head tank with a mark at the stop fueling level. Then when the level reaches that mark, add no more fuel, and the way I do it, I adjust my float valve 2 notches to slowly raise the level. My mark is at 18 gal. The last 18 gal then is in the pan before the boil stops (because of the bed of coals). I then shut off my AOF/AUF blower, cover the pans and float boxes and turn off the lights (By then I will have finished cleaning up unless I'm bottling more syrup) and lock the door.
What is in the pans will not freeze, but if real cold it will get a slush on top. The next time you have sap to boil, just start the RO and when you are almost to your stop fueling mark, light the fire. When doing this, then try to regulate the RO concentrate flow at equal to or barely over your evaporation rate. Then the head tank is only a little above the stop fueling mark. Regulate the concentrate flow by adjusting the RO pressure, higher = more permeate, lower = more concentrate. Just don't try to go above the pressure limit of your RO.
Another way, if you prefer is to lower the pressure a little and raise the head tank level for more wiggle room if anything interrupts your routine and then simply have valves set up to run head tank contents back thru the RO to reconcentrate. I often do this method. I have a line to pull from the outlet from the head tank tee (going to the flue pan) to go back to the RO infeed. If you do this, as soon as you switch the valves you need to lower the RO pressure 50-75psi, until the concentrate gets to the RO. Then you can adjust it back to just a little under (10-15 psi) what you run cold sap in at. Check the RO pressure every time you add wood, because it will climb slowly when re concentrating and will need adjustment more often.

[pdr]

Hi Dave,

Just wondering how often you have to drain and clean your pans. I end up with lots of scale/nitre/sugar sand in the syrup pan after just three or four hours of boiling. Afraid of warping it if I don't drain it after each boil. I try to drain/rinse the flue pan after two or three boils. Any thoughts/suggestions?

Paul

[mellondome]

I clean my front pan before every boil. Back pan only when season is over. Im concentrating to 18%. I will flush and filter my back pan every other boil. ( recirculate the concentrate through a filter press and back to the pan flushing any loose sand/niter out).

Front pan I will drain filter once the arch is cool enough to not burn the pan, and fill with permeate to sit till next boil.


To the original question, why do you drain and finish off after every boil? It will not hurt anything to leave in the pans. Sounds like every day you boil, you start like it is the first day of season...

[maple flats]

I check the next day, before I fire up. If it needs cleaning, I clean it then by warming the contents using a 500,000 BTU weed burner torch underneath (but only fired at about half. When the syrup pan contents are slightly warm, I shut the torch off and drain it into my draw off tank. I let it drip about 5-10 minutes after it slows to a drip. Then I add a gal. of white vinegar and again warm it with the same torch. When warm I let it sit for 30-45 minutes (I add more heat every 15 min. or so, then I brush it a, drain and flush using permeate from the RO while I RO the new sap. After a real good rinse I then open the bottom drain on the draw off tank (make sure the syrup pan valves are closed). The filter press pump moves it from the draw off tank back into the syrup pan and I'm ready to boil again. I only do the cleaning if needed, in early season I might go 2 sometimes 3 days, as the season progresses I need to more often. In late season I may need to clean it during the boil. To do that, I stop fueling and after the pan cools to about 100 degrees, I drawoff all but about 1/8-1/4 inch. I then unhook the syrup pan and lift it to a rolling cart. Then I drain the rest and move that pan outside. Then I get my spare pan, bring it in and hook it up, pump the contents originally in the other pan, using the filter press pump to the new pan and I'm getting the fire going about 1/2 hr. after I lifted the other pan off. It can take from about 30-60 minutes to cool the original pan before I can lift it off.
In the past I've only cleaned the flue pan at the end of the season, this year I added a flue pan washer and I'll be doing it every boil or 2, just drain the flue pan, then connect the washer and turn on the pump. With that, permeate is pumped thru 6 spinning spray arms into the flue pan and the permeate is sent to drain.
I see no reason to wait until the contents have cooled enough and the coals have burned out so I can drain it at the end of a boil, especially if I've been burning good hardwood since those coals stay hot a long time.

[Big Stoney]

Thanks for all the useful information. I empty at the end of the day because we are in a cold unheated pole barn. I am nervous about the evaporator freezing. I would feel a little better about leaving sap in the pan if we were more airtight. I did post something last year about leaving sap in the pan and someone posted that he had repaired a lot of sap pans that had been frozen. I did not want to risk freezing ours. The neighbor farmer years ago told me all that I needed to do was to leave a wood chip in the pan and it would not freeze solid, but would expand by the chip and not break the pan. I did not try that.

Dave, how concentrated does the sap have to be to leave it in the pan? I also tried sending you a private message yesterday about smoke stack installation. I am not sure if I did it correctly or if you received it and I do not know where a reply would be received.

Again, thanks for all of your help.

[wiam]

I have never emptied my pans because of freezing. My sugarhouse is very drafty. Not a problem. Even when I only concentrated to 5%.

[adk1]

I have never drained my pans either but a few times I thought about it. Never an issue. Can always throw in a lead light

[blissville maples]

moderate wood towards end, i usually draw 20 gals concentrate into buckets, as bulk tank has approx 30 gallons left i do last small firing and by end im using last of bucket material. just have to get used to things. use smaller pieces of wood at end, no big chunks no hardwood that will last. smaller pine, arm size and smaller, will be gone in a few minutes

[blissville maples]

you don't need to worry about freeze if running concentrate, unless your below 10 -15 degrees, i don't worry. rear pan is fairly sweet, sometimes only slushes. i guess u could use a small electric heater if gets real cold for period of days?? but once tapping very rare to see below 15 degrees

[maple flats]

Thanks for all the useful information. I empty at the end of the day because we are in a cold unheated pole barn. I am nervous about the evaporator freezing. I would feel a little better about leaving sap in the pan if we were more airtight. I did post something last year about leaving sap in the pan and someone posted that he had repaired a lot of sap pans that had been frozen. I did not want to risk freezing ours. The neighbor farmer years ago told me all that I needed to do was to leave a wood chip in the pan and it would not freeze solid, but would expand by the chip and not break the pan. I did not try that.
Dave, how concentrated does the sap have to be to leave it in the pan? I also tried sending you a private message yesterday about smoke stack installation. I am not sure if I did it correctly or if you received it and I do not know where a reply would be received.

Again, thanks for all of your help.
I did it the same way before I had an RO. At that time my sap ran about 2.2% in the early season, but at that time for my first boil of the season I made sure I had enough to boil 3 hrs. This concentrated the sap, but I don't know what % it got to. Back then, I never got to draw off on the 1st 3 hrs boil in a season, so my guess is that the 1st section in the flue pan was not very concentrated. I might GUESS maybe 5%. With that it never froze sloid, but if a cold snap ran for several days it did get slushy. My sugarhouse is also cold, the roof is steel with a vented ridge and only purlins under the steel. I also had board siding with no battens yet the first 2-3 seasons.

[maple flats]

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