Is sterilization really necessary?

[mantispid]

If I boil the syrup to 67.5 brix, do I really need to worry about heat-sterilizing clean containers? This is my first year producing (personal use), and I'm used to processing honey (where I don't really need to worry about heat-sterilizing). If the sugar content is high enough, won't maple syrup keep just like honey does?

[spencer11]

It will get moldy if left out and not in the cold if its not hot packed, I've never had it happen but it can, as long as you pack it at 185* it will seal properly and you shouldn't have any problems, and you shouldn't need to heat containers

[happy thoughts]

It's not just the brix that counts it's the packing temp. Make sure you pack at 180-185 F and fill the containers to about 1/4" from the top. You want those temps to get a good seal. Higher than that and you'll get too much shrinkage when it cools. That temp should sterilize the bottles and lids- tip the bottles so the hot syrup touches them. There will be some shrinkage in volume. Less head space means less air to support mold growth. Though I don't keep bees I don't think syrup has the same keeping qualities as honey. You need to refrigerate opened bottles of syrup. I've never put honey in the fridge.

I sterilize bottles myself since i recycle them from other uses like salad dressing. But if you have very clean or new containers, I think a really good wash should be enough imho. Try to keep the bottles warm if possible before filling if only to prevent cracking. Some keep them in a warm oven.

post edit- syrup needs to be at least 66 brix for good keeping. Less brix may mean syrup that supports mold growth and will spoil faster.

[mantispid]

Hmm.. Well, I do hot-pack it into quart or half-gallon mason jars. But once most of the nitre settles out, I crack them open and then cold-purify them using a sterile non-filtering system to remove impurities... but then bottle them into clean 100ml containers that are not heat-sterilized. I suppose I'll have to see what happens after a month or two... Then again, almost all of my friends want the syrup so it may not even last long enough to grow any mold.

[MISugarDaddy]

Like spencer11 said, you don't need to heat sterilize your containers as long as you bottle your syrup at 185 degrees to 195 degrees. You want to have your syrup that hot when you bottle into glass because of the cooling effect of glass containers. I built a device to keep my jars preheated before bottling using a small heater to reduce the chance of a container breaking and to ensure that the syrup is hot enough to kill off any bacteria in the unfilled area of the container and to help ensure sealing. After you fill each container, invert it for 10 to 15 seconds to help with this process.

[mantispid]

Unfortunately I'd like to avoid re-heating the syrup for the second bottling process after cold-purifying... Perhaps boiling the final bottles and their lids would work well enough. I'm going to have to experiment.

[happy thoughts]

Hmm.. Well, I do hot-pack it into quart or half-gallon mason jars. But once most of the nitre settles out, I crack them open and then cold-purify them using a sterile non-filtering system to remove impurities... but then bottle them into clean 100ml containers that are not heat-sterilized. I suppose I'll have to see what happens after a month or two... Then again, almost all of my friends want the syrup so it may not even last long enough to grow any mold.

It's ok to repack later but you need to reheat the syrup before packing again into new clean jars. Try to keep it under 195F when reheating so more niter doesn't form. Bottle at the same packing temp as before.

[happy thoughts]

Unfortunately I'd like to avoid re-heating the syrup for the second bottling process after cold-purifying... Perhaps boiling the final bottles and their lids would work well enough. I'm going to have to experiment.

That won't work. You can't get any kind of seal unless the syrup is packed hot at the proper temps. If you pack it cold the syrup will need to be kept refrigerated.

[mantispid]

Yeah, I figure there won't be much of a seal. I'm just trying to go for minimizing the starting amount of mold spores to retard initial growth... Long enough so that mold growth won't happen for, say six months. If I were to ever use this process commercially, I'd have to figure out a method that will never have a loss of sterility, or has a re-sterilization step. I'd likely just cold-purify in bulk, re-boil, then bottle. Re-heating syrup doesn't affect its flavor much, does it?

[happy thoughts]

Yeah, I figure there won't be much of a seal. I'm just trying to go for minimizing the starting amount of mold spores to retard initial growth... Long enough so that mold growth won't happen for, say six months. If I were to ever use this process commercially, I'd have to figure out a method that will never have a loss of sterility, or has a re-sterilization step. I'd likely just cold-purify in bulk, re-boil, then bottle. Re-heating syrup doesn't affect its flavor much, does it?

I would not advise cold packing no matter what system you have in mind. But if you're determined to try it then sterilization of your bottles and lids for at least 15 minutes in a boiling water bath just as you might do for canning would be my first suggestion. To help retard mold growth you might want to use containers with a neck like the standard syrup bottle and fill them as full as you can. Mason type jars would not be a good choice. Mold needs oxygen to grow. Minimizing the surface area of syrup exposed to air will help some. I would still advise refrigerating any syrup packed this way as there is no way you will get any kind of vacuum seal as you can when syrup is packed hot.

[Blocmi]

I always boil the jars, and heat pack. I've had jelly mold without boiling the jars first and I refuse to lose a hard days work for 30 minutes of boiling water.

Could you use melted wax to seal the jars? I remember my grandmother sealing jelly jars with it and I've seen it for sale with canning supplies. Instead of heating the syrup, Sterilize jars, fill with syrup, and use hot wax to seal.

[Darkhollow Sugar Bush]

its going to mold

[Scribner's Mountain Maple]

I agree, it will mold, been there, done that. Sterilizing jars will do little. What if you filter syrup while hot, and package right away. This will avoid this problem of having to reheat. It will be clean, packaged, and able to be stored for a long time without any problems.

[mantispid]

Alas, my purification process is incompatible with hot-packing, unless I heat the syrup to boiling a second time after impurities are removed. Does purified syrup generate more sugar sand if it is boiled once again?

[maple flats]

Yes, anytime you heat it to where steam escapes it forms sugar sand. Sugar sand is mostly if not all, just the minerals that could not stay in suspension because it was super saturated (maxed out on holding the minerals in suspension).
You must either hot pack or keep it refrigerated (or better yet, in the freezer, it will not freeze).

[mantispid]

What happens if one uses deionized water to dilute down to, say 60 brix and then boil back to 66 brix? Might that avoid production of additional sugar sand?

[happy thoughts]

What happens if one uses deionized water to dilute down to, say 60 brix and then boil back to 66 brix? Might that avoid production of additional sugar sand?

I don't think so. It's the temp needed to bring it back to density that will cause more niter. Even syrup at the correct density will precipitate more niter if brought back to temps nearing 200F. I don't see how diluting it then reboiling will help any. Can I ask why you don't want to reheat before repacking?

[Blocmi]

Is your concern sugar sand forming in your finished syrup after you reheat?

If you only reheat to 180 any sugar sand if at all will be minimal and I wouldn't be concerned.

[happy thoughts]

mantispid- This is a nice short downloadable goodie from the university of maine about maple syrup quality control. Here's what they have to say about cold packing, mold growth, reheating and niter formation.

Maple Syrup Quality Control Manual - The University of Maine
http://www.umext.maine.edu/onlinepubs/PDFpubs/7038.pdf


“Cold” pack has caused more spoilage of syrup than almost any other factor. Always pack syrup hot! When packed at the right temperature, the hot syrup will sterilize its container, preventing spoilage. Then, when properly sealed, a vacuum will be created, preventing contamination.

The lowest safe temperature for packing syrup is 180 degree F when the cap goes on. Syrup that is left uncapped for a few moments can cool sufficiently and collect enough yeast and mold spores from the air to spoil some cans in an otherwise perfect lot.

Research by Dr. MariaFranca Morselli of the University of Vermont Maple Research Center indicates that packing syrup at temperatures higher than 180 degrees F (but not higher than 200 degrees F) will result in fewer trouble-causing microorganisms. However, if temperatures are raised too high for too long, new niter may precipitate, causing cloudiness. (Refiltering reheated syrup can eliminate cloudiness.) Continue to check temperature with a sterile thermometer immediately prior to filling the container.

[happy thoughts]

Is your concern sugar sand forming in your finished syrup after you reheat?

If you only reheat to 180 any sugar sand if at all will be minimal and I wouldn't be concerned.

Not to nitpick but reheating to 180F might not be hot enough for safe packing and a good seal. Syrup needs to be at a minimum of 180F when the cap goes on. Syrup is going to cool a bit transferring from the pot or canner to the bottle just like it does from the pan to the hydrometer cup. Keeping bottles warm will help. Bringing the syrup up to a little higher temp will also help. I usually start packing when the syrup is about 185-190F.

[emo]

Hot packing is the best way to avoid spoilage in anything you jar/can/preserve. If it is not packed correctly, anything can go bad; just when syrup goes moldy, it is easy to see. Wife has Zuccini relish from 5 years ago that is still good. I have boiled the jars lids and rings for at least 5 minutes after you get a good boil and heat the syrup to at least 180. This year I have reheated the syrup to 180, boil the lids and rings, but run the jars through a high temp wash in the dishwasher by themselves, only bringing the jars out when I need them. Have next to no new niter in the jars and only 1 jar out of about 25 did not seal. When I boiled the jars, if the jars and syrup were both really hot, I got sugar crystals on the bottom of the jars. Wife would get the crystals out, run it through a coffe grinder and use it as sugar in baking or as a sweetener in coffee; said it gave the coffee a slight maple flavor.

[mantispid]

Correct, my concern is additional impurities forming after I just spend time removing impurities. My method doesn't use any filtration at all, so is faster and doesn't lose any syrup to filters. Plus, it also reserves the niter for other purposes. I'll put together a set of experiments to determine just how far I'll need to go to minimize mold growth. I'll have a couple small bottles that are cold-packed, and then will do the same with heat-sterilized bottles/lids, and then finally do the same with heat-sterilized bottles/lids with ~195F syrup. I'll leave just enough air space to be able to see any growth without opening the bottles. (These are all 50ml maple leaf nip bottles).

[Blocmi]

I do the same as you. No filters, just gravity. I've never had a niter or mold problem re-heating to 180 and filling sterilized jars. I am meticulous about sterilization... The jars and lids come out of boiling water and only sit long enough on clean dry paper towels for the water to dry out of them.

[happy thoughts]

Just an FYI- somewhere in the back of my brain from a few years back I remember some posters saying that use those leaf nips are especially prone to mold growth. Again, if I remember correctly if at all, packing into hot bottles helped.... that's of course hot syrup we're talking about. The thought I believe was that those bottles cooled too quickly for good sterilization from hot syrup. FWIW, I think the nooks and crannies in those bottles may also be a factor in that they are hard to clean so that any mold spores in them to begin with may be harder to remove than in a more straight sided container. Sterilizing them before packing should also help I'd think, though a recently cleaned warm jar packed with hot syrup should accomplish the same thing.

And that said, people reheat syrup for repacking all the time. Bulk container storage for later repacking is common. If you're careful not to go above 190-195F on reheating, more niter formation shouldn't be a problem. For something that took so much time and effort to produce, packing cold is not worth it because of the high risk of mold growth.

[mantispid]

Hmm... what about baking the filled bottles in an oven at 190F for say... 30 minutes? Lids just loose enough to allow for pressure equalization, then tighten them down when removing. Think that might work?

From here on out I'm going to boiling water sterilize the bottles, then fill with ~190F purified syrup.

[spencer11]

Hmm... what about baking the filled bottles in an oven at 190F for say... 30 minutes? Lids just loose enough to allow for pressure equalization, then tighten them down when removing. Think that might work?

From here on out I'm going to boiling water sterilize the bottles, then fill with ~190F purified syrup.
I think that would melt the cap unless they were metal, I'm pretty sure it would weaken the glass to

[Run Forest Run!]

Hmm... what about baking the filled bottles in an oven at 190F for say... 30 minutes? Lids just loose enough to allow for pressure equalization, then tighten them down when removing. Think that might work?

From here on out I'm going to boiling water sterilize the bottles, then fill with ~190F purified syrup.

Definitely do not put filled bottles in the oven. Sterilize them in water prior to filling.

I don't know what your water is like, but mine is very hard. Sterilizing bottles in hard water leaves a chalky film on the glass and inside the jar. After a few years of trial and error I've hit upon the solution. My hot water talk is hooked up to a water softener. I use hot water to fill my canning pot and then add some white vinegar (about 1/3 cup) to the pot. The combination rids all of the residue that one plagued my jars.

[lpakiz]

First, what is cold purifying??
You can place filled jars in a water bath canner, making sure the jars do not touch the actual bottom of the canner. Insert a Taylor digital thermometer probe in one of the jars. When it reads 185 turn off the heat and install the lids. Done.

[mantispid]

I think that would melt the cap unless they were metal, I'm pretty sure it would weaken the glass to

No melted cap! I experimented with one bottle. Of course, a sample size of one is never useful for predicting how well a process works. It could very well weaken the bottle.


Definitely do not put filled bottles in the oven. Sterilize them in water prior to filling.

I don't know what your water is like, but mine is very hard. Sterilizing bottles in hard water leaves a chalky film on the glass and inside the jar. After a few years of trial and error I've hit upon the solution. My hot water talk is hooked up to a water softener. I use hot water to fill my canning pot and then add some white vinegar (about 1/3 cup) to the pot. The combination rids all of the residue that one plagued my jars.

Yeah, this weekend I'll be using water. Had to experiment though. It is the scientist in me. ;) My well water is ridiculously hard, but I have a softening system that works quite well. No more chalky residue when I can things.


First, what is cold purifying??
You can place filled jars in a water bath canner, making sure the jars do not touch the actual bottom of the canner. Insert a Taylor digital thermometer probe in one of the jars. When it reads 185 turn off the heat and install the lids. Done.

It's a process I'm working on. Might be patentable. We'll have to see if I can work out the bugs with the whole sterilization thing! Almost makes me wish I had one of those gizmos for radiation-sterilizing food, like what they use for shelf-stable milk. Hmm, I may just do what you suggest regarding the hot water canner. The trick will be regulating the heat on my stove. It isn't known for precision...

[lpakiz]

Mantispid,
You really don't need any heat regulation. Just place the filled jars in the canner on a rack to keep the bottoms of the jars off the floor of the canner. Don't over fill the bottles, as the syrup expands way more then you think. You can top off the jars later, when they are almost at final temp.
Add enough water around the bottles to get the water about even with the shortest bottle. Turn the burner on MAX! Insert the probe from the Taylor thermometer into one of the syrup jars. Set the programmable alarm to 180. When the alarm goes off, start to boil the lids if using Mason/Ball canning jars. When it gets to 185-188, turn off the heat and extract the jars. Apply the lids. They will seal when the syrup cools.
The Taylor thermometer is available at the big box stores or at our local farm supply chain store. About $16-20