Continuous Flow Process - how long is too long

[Fort Wisers]

Good day everyone.....
First, many kudos to everyone who maintains and contributes to this forum, it's a wealth of information, especially to those just getting their feet wet like us!
Second, here's our situation;
We have a very small operation being only 6 taps, so far we've collected close to 100 litres of sap and plan to add 1-2 more taps before the season is complete.
Last year and the first part of this year we had been boiling on a small woodstove modified to accept a turkey deep fryer pot.
Last year we were successful with it and this year we planned to carry on as is.
Long story short, without getting into too much detail, we ended up getting a decent deal on a larger (as in larger to us, it's still just a small hobby unit) evaporator system.
It's not a dual pan continuous flow as is normal (flue + syrup pan).
It has a single pan, ribbed (sort of like dropped flues to increase surface area) and baffled to create the gradients from one side to another.
Although it's single pan it does have the ability to produce finished syrup from raw sap, we saw this at the manufacturers site who is running a 1000 tap operation of larger versions of what we bought).
This process is new to us, obviously, and we've already learned a lot just get started, but we have much much more to learn!

We've boiled down our entire ~90 litre supply and are now waiting on more sap. We boiled on Sunday and anticipate another boil tomorrow or Thursday.
According to calculations, based on Big Eddys post, it will take about 500 litres to sweeten the system and start producing, a number we simply won't hit with our tap count.
Basically we're way over capacity in terms of evap unit vs sap production, but we bought it with the intent of expanding taps count, it just won't happen this year.

So our plan is to boil what we can, as we collect, until roughly mid March (generally when our trees start to dwindle in terms of production).
Then when the trees stop producing we'll transfer the half finished product to our old system and finish on that, since we'll never hit enough to truly sweeten the larger system.
We plan to boil every 2-4 days depending on what our trees produce and weather.

So our question is, assuming weather stays cool enough to not cause rapid spoiling, and assuming it doesn't go so cold to run the risk of freezing the product hard and risk cracking the pan.
If we boil every 2-4 days or so, leaving the half finished product in the system, is it ok to continue doing this until Mid Mach or is there a time limit half finished syrup should stay in a continuous flow system?
We know most folks running this method leave their system sweetened all season (or maybe a break or two in between) but what about a case like ours where we'll never hit the point of full sweetened?


Does this sound reasonable, are we way off course?
And yes, we realise running a continuous flow system with such a small amount of sap production makes little sense LOL!

Thanks for any input/guidance you can give!!

[Michael Greer]

An interesting conundrum. First, half finished product won't freeze. Sap will freeze and could damage things, but by the time you've reduced it that much, you've created a liquid that's a bit like anti-freeze. To my mind you're more at risk of losing your syrup to spoilage. It wouldn't surprise any of us to see a few 60 degree days in March, and that's too warm. If possible I think I would take off the unfinished liquid and put it in the freezer until the end of the season and finish it all at once. If you are lucky enough to be able to cook every few days, the boiling will keep the syrup sterile, and no precautions would be necessary. Tapping more trees next year will solve this problem...and give you new ones. Have fun.

[Fort Wisers]

An interesting conundrum. First, half finished product won't freeze. Sap will freeze and could damage things, but by the time you've reduced it that much, you've created a liquid that's a bit like anti-freeze. To my mind you're more at risk of losing your syrup to spoilage. It wouldn't surprise any of us to see a few 60 degree days in March, and that's too warm. If possible I think I would take off the unfinished liquid and put it in the freezer until the end of the season and finish it all at once. If you are lucky enough to be able to cook every few days, the boiling will keep the syrup sterile, and no precautions would be necessary. Tapping more trees next year will solve this problem...and give you new ones. Have fun.

LOL, love that last statement!
So, in your mind, if we're boiling every few days we should be ok?
If we see a few days of warmer weather in the forecast, the idea then would be to abandon the original plan and just empty it.
We'd work our plan until weather didn't permit us.

Thanks!

[maple flats]

You certainly have too much evaporator for 6 taps. Even with what you think might be just week to 10 days left, I'd add at least 10 more taps. Then boil at least every 2 days unless it is too cold for sap flow. If too warm, don't let it stand more than 3 days, in that case, drain the pan and put it in the refrigerator. Then when you get more sap and are ready to boil again, put it back in the pan and boil. If the sap doesn't come again, finish as you suggested using the old method.
One result from having far too much evaporator for the taps you have, is that your boils will be too short, and repeated short boils will result in much darker syrup generally. Don't get me wrong, Dark is my best seller, but Very Dark is slow seller. Many people only like to use it for cooking because the maple flavor is far stronger, but a few want it for table syrup for that reason. Just be aware of what several short boils is likely to yield.

[Fort Wisers]

Thanks Maple Flats, appreciate the advice.
In our case we're fine if it turns out dark because we're not selling or even giving away the product, at this stage we're just using it for ourselves.
So it's a good time for us to experiment and learn a little.
Just for our own knowledge what duration would you consider a short boil vs a normal boil?

Totally agree that we need more taps for the evap unit.......

Thanks for the response!

[Sugarmaker]

Short boil vs long boil is all about how fast your evaporator will process sap vs how much sap you have.
I missed waht size your rig is. Bu lets use a 2 x 6. boil rate about 30 gallons per hour.
Your 6 to 10 taps may produce from 1/2 gallon to 1 gallon of sap each run. say 3 to 10 gallons of sap. You would need to save sap for several days, Even then your boil time may be only a hour or two.
Just guessing. Example: Our 3 x 10 can boil about about 130 gph. so 140 gallons of sap takes about a hours boil time.
Keep gathering and boiling!
Regards,
Chris

[crzypete]

I am pretty new to this but have been reading a ton, so I give you this thought with a grain of maple sugar. I would run it as a batch pan rather than a continuous flow, boil a batch and empty it. repeat as you get enough sap. Plan on tapping enough trees to do continuous flow next year if that is your prerogative.

Pete

[Fort Wisers]

Thanks guys appreciate the advice!
We'll keep you posted how things turn out!

[bigschuss]

Thanks guys appreciate the advice!
We'll keep you posted how things turn out!

Good luck. I'm on a small 2x4 evaporator and sometimes I think my 90 taps aren't enough to keep it fed. When the saps flows slow or are non-existent I do what crazypete said and just to batch boils. I'd rather do 3 or 4 batch boils and have to start over sweetening the pan each time, then lose 2 or 3 gallons of almost syrup waiting for the next run.