sap jugs froze solid

[michael marrs]

I just went to where I tap my trees, and all my jugs, ( milk), are icebergs. I could take them inside, but I have 74 of them, and not sure I want to do that, and a real thaw of sorts could be a week off. I will have to play things by ear. I have only done this about 5 years, and every year so far, the weather has stuffed it to me in some fashion

[BoarsNest]

I'm sure mine are all frozen as well. My sugar bush is about an hour north of GR and that makes this weather a pain. Last year one weekend we had 5 gallon ice cubes and it was highs in the low 20's. The one day we threw out the sap because it was going to warm up the following week and I didn't have storage for 200 hundred ice cubes.

[maple flats]

As long as it stays cold the sap will be good. Being in milk jugs you can't throw the ice out, but when it is half ice and half liquid, you could boil the now concentrated sap. But without another jug to replace it, you would further dilute new sap that ran into the jug, as it melted the very low sugar ice.

[Haynes Forest Products]

Its not going bad so what you do is when the weather breaks and the sap starts to flow it will start to thaw the jugs. Go out and collect as usual the new sap with thaw the ice and it will take a few days but it will all work out. I hope you have a few inches to spare for new sap. Think of it as a frozen water bottle and as it thaws you just remove the liquid. Don't go banking the jugs on the tree ripping threm up.

Its all good sap so don't fall for the idea that after some of it melts all the rest of the ice is 0% sugar. I cant wrap my head around the idea that only pure water froze in the center of the sap and worked itself into a complete frozen blob of only pure water with a outer coating of all the sugars and minerals.

[Cedar Eater]

Its all good sap so don't fall for the idea that after some of it melts all the rest of the ice is 0% sugar. I cant wrap my head around the idea that only pure water froze in the center of the sap and worked itself into a complete frozen blob of only pure water with a outer coating of all the sugars and minerals.

This is opposite of how a vessel of sap freezes. They freeze from the outside to the inside. The water in the sap gives up its heat to the outside colder air. Since water freezes at a higher temperature than a mixture of water and almost anything else freezes, water molecules stick to the ice forming on the outside and very few of the sugar molecules get stuck in it. So the center slowly becomes more and more sweet, postponing its freezing even longer and giving the water molecules more time to stick to the outside. You can test this by sticking a straw into the center of a partially frozen jug of sap and tasting how sweet it is. If you drain the liquid center out, it will have a high concentration of sugar. If you then thaw the shell of ice, it will have a low concentration of sugar. This is proven and testable. It will have some sugar, but it will be a gradient with the least sugar in the ice that is closest to the outside and progressively more sugar in the ice that is closer to the center. So you can save fuel by not boiling the low sugar sap that comes from melted ice without losing much sugar in the process, but you will lose the least sugar if the vessel is only slightly frozen. The more frozen it is, the more sugar you would lose if you threw the ice out.

[Haynes Forest Products]

So there is no real way to defrost the milk jugs of the outer pure water to save the sweet inner concentrate. I still cant wrap my head around it. All the Popsicle I eat are sweet from the outside to the inside.

Now Michael could drill a hole from the top into the sweet inner area and drain the sweet out like a coconut. Or just allow the warm sap to thaw the entire jug full of sap and get back to cooking.

[Cedar Eater]

Yes, unfortunately, unless you time it right and either break up the ice or tap into the center of it, getting the concentrated sap out is tricky. A vessel will normally thaw from the outside in, so the first meltwater should be low sugar content, and theoretically you wouldn't lose much sugar if you dump say the first 10% by volume. But there is no way to tell when the good stuff starts to melt into it other than by testing for a rise in the sugar content to whatever minimum you decide is worth boiling.

A popsicle is much sweeter than sap and it is a small thing being frozen pretty quickly in a freezer that is typically well below 20 degF. Sap is typically being cold-concentrated much more slowly in a large vessel between 32 and 20 degF. Time allows the water to create the sweetness gradient. What I described about the freezing of sap is testable. You can observe that it will freeze from the outside in and you can test the sugar content of the liquid core vs. the outer ice shell. But if the jugs freeze solid, that becomes problematic. Thawing a jug from the inside to the outside just isn't practical.

[Mark79]

If it were me I would bring all 74 jugs inside to thaw out quick so you have them ready for this weekends run. :)

[Haynes Forest Products]

So the decision is to throw the sap out or cook it??

[Mille705]

I would bring them in tomorrow to thaw, cook the sap and be ready for the next run.