Help identifying bottled syrup issue.

[BlueberryHill]

I should know the answer to this! Kind of embarrassed to ask. I have a jug of syrup on the shelf that has the sides "sucked in". I'm guessing some kind of contamination in the bottle? Fermented? Have not cracked it open yet to check. I have scores of other bottles and they are all good. It's all from this spring. Thought it was weird that this one random bacon jug is like this. Never had it happen before.

[TapTapTap]

I'm new to sugaring but I'm pretty good at physics. So I'll offer up my 2 cents:
- it can't be an organic reaction because that would create gas and expand your container.
- it seems more likely that there was enough empty headspace over the warm syrup when it was bottled that it created a vacuum when it cooled that was enough to cave in the container.

[lew]

I agree with Ken. Perhaps you thought the jug was full but really had excess foam in it causing a void.

[n8hutch]

I had this same problem with the Bacon Jugs in particular the half gallons, I would fill them rim full with 190-195 syrup and when it cooled a combination of the syrup shrinking and the cooling would suck the sides in, switchEd to a different brand of container and it hasn't been a problem.

[maple flats]

That is not a jug manufacturer type issue. You either had foam or over filled the jug, and your temp was too hot. Don't fill at over 190 and don't fill all the way to the top of the neck, filling at 184-188 is best. A full measure is just at the bottom of where the cap threads start. If you fill above that you leave no space for a vacuum to occupy and then the sides of the jug are sucked in. If you have a truly accurate scales, weigh the jug as filled and subtract the weight of an empty jug. Should be 11 lbs. If you don't have that accurate of a scale this will not work and if density is off too much it won't either.

[n8hutch]

Your certainly welcome to your opinion Dave, I have never had an issue with any other container, just the Half Gallons, I always check the Density of the syrup before I fill containers, generally it's a cold test. Regardless I have had that problem with multiple Batches of half gallons, so I gave a different container a try, used the samend
Methods and no problems since, my target heat temp is 190 but as you know I'm sure it's not always that easy to maintain exact temp.

[WESTVIRGINIAMAPLER]

I run syrup through filter press at boiling and often bottle at temps over 200 and have never had an issue with a jug sucking in with either Les Cruchon or Sugarhill which are only 2 brands I have ever used. I shoot for a target temp of around 190 but for first third of batch temps are much higher usually until it cools off some. I bottled many thousands of bottles in last 15 years like this and have no nitre issues either in plastic or glass because the syrup is that temp coming through the press.

[maple flats]

OK, that was just my thoughts. I've never had any suck the sides it.

[n8hutch]

No worries Dave, guess I may have come off a little dismissive, didn't intend to do that, I Value your opinion and ideas , it's all good stuff. Maybe I was doing something wrong but it's working for me know, I agree best thing to do would be to fill them bye weight not volume but I haven't gotten that far.