Bottling and storage woes

[Johnnyjohn]

Hey all, perhaps you can help me out with this dilemma.

We are new to bottling maple syrup and have been having some issues with mold development on our bottles - we bottle in clear glass bottles 375 ml and 750 ml formats using a synthetic bar top cork.

First, we test our syrup for brix, and it is always above 66.6. Next, we heat our syrup in the boiler pan, run it through the a warm press and then into a 32 gallon closed top bottle filler at 200 F. All of our bottles and corks are new, shipped directly from the factory. We preheat our bottles in a water bath and bottle each one by one. We do routine spot checks with a thermometer to ensure that the syrup is always over 185 F after it has entered the bottle. Directly after filling we cap the bottle and turn it upside down for at least 1 minute to sterilize the headspace and the closure. Once they have cooled, we put them in boxes and store them in our house which maintains an ambient temperature of about 68 F. <

We have had problems with mold developing on the surface of some bottles and are trying to figure out why. Whenever we remove a cork from the bottle, there is clearly a vacuum tight seal as the removal of the cork is met with some resistance (the cork actually gets sucked back in if not removed fully) and makes a distinct pop sound when it comes out.

Could the problem be due to condensation forming inside the bottle and creating a layer of diluted syrup on the surface? Is there an ideal temperature and humidity level at which to conduct bottling? Same for storage?

Any information would help.

Thanks

[Indiana-Jones]

Are you getting water inside the bottle from your water bath? Two years ago we had some mold in some bottles and we were submerging the glass in the hot water bath and then filling. Last year we used canner grippers and held each bottle one at a time in the hot water up to their neck to preheat then filled. We had no mold.

I think and it was suggested here on the board that getting water inside the bottle allows a few drops of water sit on top of the syrup to mold.

Just my two cents worth.

Chris

[regor0]

Are you using new or used cork? I used to bottle the same way you do. I also had mold issues. I now use glass with plastic caps. I think the problem is the cork, it's very hard to get all the bacteria killed in that cork. Since changing to plastic caps I've had no more mold.

[rayi]

Corks can let small amounts of air in. Wine ages in a bottle because of this. After some time the wine will become cooking vinegar

[Johnnyjohn]

Thanks for the input guys.

We are using brand new synthetic plastic corks which is why I don't understand why we are getting mold since I have seen others such as Crown Maple that use the same type of cork.

[Big_Eddy]

I've never used cork so can't say for sure.

I expect the issue is that with the increased thermal mass of the cork (and insulating properties of cork), your 1 minute inversion is not enough time to bring the whole cork up to temperature. With a plastic cap, there is a small thermal mass so inverting the botle allows the cap plastic to come up to temperature and kill off anything. Even still, when I bottle, rather than just inverting, I always lay my bottles down for 10-15 mins to ensure the cap is sterilized.

I'd suggest you try leaving your bottles on their sides for a while as well. You need to get the whole volume of the cork up to 170 and I doubt 1 minute is doing it. Either that - or try pre-sterilize the corks in a hot water bath or a 200 degree oven.

Different but related question - what temperature are your corks rated for? I don't make wine, but I don't think it is ever boiled. Are the corks even suitable for exposure to boiling temperatures?

[happy thoughts]

Thanks for the input guys.

We are using brand new synthetic plastic corks which is why I don't understand why we are getting mold since I have seen others such as Crown Maple that use the same type of cork.

My money is also on the corks as the source of your mold. I'll bet CM is sanitizing theirs in some way. When used for wine they are usually sanitized with sulfite solutions. That probably won't fly for maple syrup and might be considered an additive, (possibly an illegal one) depending on what your particular laws state.. Some people are also sensitive to it so I'm NOT recommending it's use for syrup in any way.

[Brent]

Looks like the only thing you're doing different from most of us is using the corks.

My 2cents worth. Drop the corks.