Keeping sweet from going ropey

[Bricklayer]

This was the first year I’ve boiled above 12% concentrate. I aimed most times to get to 14%.
This was also the first year I’ve ever had the sweet go ropey on me in the pans. Turned to a snotty goo. And not easy to clean out of the pans.
I followed the same shut down procedure that I have done for the past couple years using Comcentrate.
Boil till I have 30 gallons left in head tank. Fire , bring front syrup pan level up about 1” above set level Flood back pan with the 30 gallons till head tank is empty. Let it come to a boil. Even if I have to fire again to get it really rolling I will.
Then I’m usually cleaning stuff and putting stuff away. So I wait till fire burns down and turn blower off and go home.

Never had a problem like this.

In between boils this year the max was 3 days. It stayed pretty cold and there was days where there was ice in the pans. So I didn’t worry about it spoiling.

I did 2 drains and pan washes this year. To keep the pans clean and keep the nitre from building up.

I’m wood fired. So on off days it’s pretty hard to just fire it up and bring to a boil and shut it down. Not really an option.
Is there anything I should be doing different to prevent this.

[BAP]

Bricklayer, do you make sure that the sap in the float boxes get hot enough at the end? I take hot boiling sap out of the pan and dump it back into the float box on the flue pan to make sure that the sap in the float box has come up to temperature enough to kill the bacteria that causes it to go ropey.

[tcross]

can you drain your float boxes? on mine i can, and i empty them and put them in the flue pan to boil. i also drain my sight glass so nothing stays in there. in my set up, i have 2 front pans. when i shut down i take of a a gallon and a half to 2 gallons of sweet and then flood the front pans and plug them. other than that, my shut down procedure is about the same as yours.

[TapTapTap]

Hi Bricklayer,

Perhaps your sap was already spoiled prior to concentrating and boiling. I've never had a ropey sweet while we're still in the colder end of the season.

We are set up very similar to you - 30"x10' wood fired, look to sweeten to about 14%, do the last fire at about 30 gallons. However, we just continue pushing the concentrate through as we do throughout the boil. We don't flood the pans and I don't see a need to do so. By flooding the pans with concentrate late in the boil, you may have reduced the sugar enough to make it more susceptible to spoiling. In addition, late in the season we will drain the pans for cleaning after every boil and we hot-pack the sweet into ss barrels (front and flue pans separately). This allows us to keep the pans cleaner and less susceptible to spoilage while also better preserving the sweet in the hot-packed barrels.

Ken

[ennismaple]

We've had the same thing happen in less time when barely above freezing. Putting concentrate into the back pan without really getting it to a boil as the fire dies down (in our case due to a power outage) has been the cause of a ropey flue pan in the past.

I agree with the comments about draining the float box and sight tube - both can be the cause of bacteria buildup that will work its way into your flue pan. We fire hard until we're almost out of concentrate and then add about 40 gallons of permeate to the head tank to flush the preheater and float box and dilute the concentrate in the flue pan a bit. We also run the blowers until we leave the camp to push as much heat our of the arch as possible and try to leave the front door to the fire box open a bit when we leave to get it cooled off quicker.

From my own casual observations, the bacteria in sap seem to really like concentrate that's in the mid teens and rapidly multiplies under the right conditions. I've never had the front pan go ropey.

[Bricklayer]

So I have never added boiling sap to my float box. But that makes sense. I do have a separate valve to drain the inlet portion of the float box. So that’s an option too.
I have always thought about adding permeate to the head tank on shut down but never done it. I usually wash out the head tank the next day so always try to have it empty. But I think that by doing this I could give the concentrate a way better boil without running pans dry. Thanks for the tip on that.
A couple gallons of permeate in the flue pan wont hurt anything.
Draining all the sight glasses is a great point as well. I usually only do it when we are getting a good freeze up overnight. So that’s gonna get added to the list as well.

I’m also thinking of just doing a full pan drain 1 or 2 times a season , give the pans a good wash and then re-sweetening the pans. With 14-15 % concentrate it Dosnt take long to resweeten.
I usually drain the pans a couple times a season anyways and save the sweet and filter it and put it back in after pans are clean. So it’s just 1 more step to the process to boil the old-ish sweet down and start over.
Syrup pans are drained and cleaned after every boil anyways. So not much more work.

[DrTimPerkins]

All good advice...for more details:

https://mapleresearch.org/search/?_sf_s=ropy

Also, https://mapleresearch.org/pub/manual/ page 7-24

[ennismaple]

I’m also thinking of just doing a full pan drain 1 or 2 times a season , give the pans a good wash and then re-sweetening the pans.

That definitely helps. Large producers drain their flue pans and rinse with permeate after every boil. We try to do a full wash at least once per week and more frequently towards the end of the season. I don't believe it messes up the gradient as the entire flue pan will slowly mix to the same sugar content throughout once you stop pushing fresh sap/concentrate.