Can Sap be Boiled Too Hard???

[Maple Man 85]

I was cooking this weekend and considered the idea of if sap could be boiled too hard? My thought was as long as I could keep it in the pan I wasn't boiling too hard. Any thoughts...

Maple Man 85

[motowbrowne]

Yep, as long as it stays in the pan, you're good to go. Check out a video of an intense-o-fire, force 5, inferno, etc evaporator running sometime. Them things boil HARD.

[Cedar Eater]

I think it can, but probably not at the temperatures a wood fire can pass through a stainless steel wall. If you got the temperature of the pan floor up to cherry red, you would probably be coking the sugar molecules.

[lpakiz]

Raw sap cannot be boiled too hard. It's science. Evaporation is a cooling process. The hotter you attempt to get the sap, the faster it evaporates, thus cooling it down. Water will NEVER get hotter than 212 (theoretically) depending on elevation and barometric pressure. You will never get the pan material hotter than the boiling point, as long as the sap is in full contact with the bottom of the pan, which conducts the tremendous heat produced under the pan, into the liquid and out as steam, cooling itself.
Now, where you need to be careful is when the water (sap) gets closer to syrup. Then the liquid cannot evaporate fast enough to use unlimited heat. Then the liquid becomes more bubbles and less liquid in contact with the bottom of the pan metal. Now, you can get in trouble if not enough real liquid is not in contact with the very hot pan material.
Or another way to say it is, you must be able to conduct all the heat produced under the pan, into the liquid on the other side of the pan, in order to keep the metal cool enough to not damage it.

[MaxJ]

Raw sap cannot be boiled too hard. It's science. Evaporation is a cooling process. The hotter you attempt to get the sap, the faster it evaporates, thus cooling it down. Water will NEVER get hotter than 212 (theoretically) depending on elevation and barometric pressure. You will never get the pan material hotter than the boiling point, as long as the sap is in full contact with the bottom of the pan, which conducts the tremendous heat produced under the pan, into the liquid and out as steam, cooling itself.
Now, where you need to be careful is when the water (sap) gets closer to syrup. Then the liquid cannot evaporate fast enough to use unlimited heat. Then the liquid becomes more bubbles and less liquid in contact with the bottom of the pan metal. Now, you can get in trouble if not enough real liquid is not in contact with the very hot pan material.
Or another way to say it , you must be able to conduct all the heat produced under the pan, into the liquid on the other side of the pan, in order to keep the metal cool enough to not damage it.
You hit the nail on the head Ipakiz on how it works and how one can get into trouble with the latter point of not enough liquid in contact. I experienced it first hand last Wed. night everything was boiling great then 5 minutes later it was all over except for the blue air of curses at my stupidity of leaving the shack to empty a container.
13769

[Sugarmaker]

max,
That was not a good thing! How did it clean up?
Regards,
Chris

[BreezyHill]

Be very careful at the end of season or dusring warm stretches as we are in now. If the sap degrades you will be into ropey syrup...this is very easy to boil to hard. I did it Saturday night. Small burnt area on the finish pan. Shortly after we stopped for the night, let the rig cool, drained the pan and filled with permeate. The next morning drained off all but 1/4" of the permeate and cleaned off the black spot with the air drinder and a polished wheel. 10 minutes with that and then let the permeate flow thru to rinse her down for 20 minutes and we were ready to fire again.

Ropey sap is stickier than regular sap and will allow a larger bubble of steam to form. if this buddle is to large you will have an air pocket form by the metal for a split second. To much fire...like from our new AUF fan.. and you can burn the pan. This syrup is what a butcher wants to use to do maple smoked meats. It can be a pain but he pays $3/# in 5 gallon jugs so we do it rather than dump the sap.

Never had an issue in the flue pan only the finish pan. I recall years that dad would just quite as it was to hard to not scorch the pan. We did the same last season. If it has a burnt flavor it wont work for the butcher.

[Maple Man 85]

Thanks for the advise everyone, I run a flat pan with a jimmy rigged continuous flow from a tank so I never lose boil. Running wide open I have roughly 1" of sap in a 8"deep pan with 4" of bubbles evaporating 20gph. Every batch (5-8 gallons) of syrup I clean the pan because there is a copper color on the stainless bottom. Just didn't know if I was firing too hot. I've see copper colored stainless stacks due to heat but haven't heard or seen it in a pan before (other then mine).

[Flatpan1]

My ss pan gets that copper color on it too,after along boil. Not sure what it is. Vinegar and water and some heat it come off rinse well and back to boiling.

[obi96]

Something must have been in the air, my pans looked like they had a melted sugar daddy in them too. I was getting rained on Saturday night and shut it down with a inch in the pan, hosed the fire down completely and went to bed. Woke up to a sticky mess. The lesson? Bricks (first year using them) hold a lot more heat than than I thought. They dried the unburnt wood and re kindled the fire. At least it didn't scorch.

[motowbrowne]

Something must have been in the air, my pans looked like they had a melted sugar daddy in them too. I was getting rained on Saturday night and shut it down with a inch in the pan, hosed the fire down completely and went to bed. Woke up to a sticky mess. The lesson? Bricks (first year using them) hold a lot more heat than than I thought. They dried the unburnt wood and re kindled the fire. At least it didn't scorch.


I wouldn't recommend hosing down hot bricks. I think that's likely to break them. If you're gonna walk away and not come back in an hour to check on things, put a few inches in that pan.

[MaxJ]

max,
That was not a good thing! How did it clean up?
Regards,
Chris
The metal worker tried to flatten the pan but the centre is bowed. Tried two different pan cleaners on the burnt mess and both didn't do squat, so I spent many hours with an one sided razor blade as it was the only thing that would get the burnt material off. Did my first boil with the pan yesterday, it pools a bit deeper in the centre section, but it'll work until the new pan arrives.

[DrTimPerkins]

Be very careful at the end of season or dusring warm stretches as we are in now. If the sap degrades you will be into ropey syrup...this is very easy to boil to hard.

Good example. Another way to run into the problem of boiling too hard is if you have a build up of niter on your pans. This can create hot spots and scorch the niter and the syrup, and create bows and pockets in the pan.

[Flatpan1]

Is niter the copper colored coating on the bottom of the pan.

[psparr]

Is niter the copper colored coating on the bottom of the pan.

Kind of. More of a tan yellow.

[Maple Man 85]

Interso-fire's, votex, and force 5 evaporators get away with boiling hotter than I am based on the pictures I've found how are they not wrecking pans by boiling to hard? I understand that there is more structural integrity in a sectioned or flue pan but that shouldn't effect the temperatures they reach. How are the pros maintaining the integrity of their rigs?

[motowbrowne]

The sap keeps the pan cool, that's really all there is to it. Same reason you can boil water in a paper cup.