Foam while bottling

[Tweegs]

We bottled up 15 gallons yesterday. 5 gallons medium, 10 gallons dark.

Normal procedures were followed:
Taste tested the batch for off flavor, checked density, sterilized the containers with hot water, heated the syrup 180 to 190, filled and capped the containers, laid them on their side.
We’re careful not to agitate the syrup while filling the container…or at least minimize agitation as much as possible.

In the glass containers we noticed that as the syrup began to cool a great deal of foam developed.
This only happened with the dark syrup and it was bottled last, which rules out any contaminate in our bottling equipment.
We’ve experienced this before but never to this degree. Usually, the foam will dissipate overnight to a small, thin ring in the neck.
This morning, there is still a 1/8 inch mat of foam floating on the surface. It looks like it may continue to dissipate, but right now, to a customer, it would look like mold.
I’ve tumbled a few of the glass containers end for end and that seemed to reduce the mat, initially, but foamed like crazy again after a few minutes.

In the past, this foamy “problem” syrup will start to foam up again if exposed to direct sunlight while sitting in the booth at the market.
In the pic, the gallon on the left sat overnight. The center gallon was tumbled (this is also what it looked like just as it started to cool). The gallon on the right is the medium we bottled first (no issue).
It would appear that heat is a contributing factor for foam development. It’s odd though that it didn’t foam while we were heating the syrup to 180 for bottling. The foam only developed as it started to cool.


So what would cause this?
Is there anything I can do to prevent it in the future?
What do I do about it now?

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[maple milker]

I have had this happen with 8 and 12 oz bottles and the SBS red caps with the paper seal. Air would be pulled back in through the syrup as it cooled. I see you have the good caps though. Do you think air was being leaked back in as it cooled?

[GeneralStark]

I'm curious as to why you sterilize the bottles with hot water when the purpose of hot packing is for the hot syrup to sterilize the bottle. I do personally preheat glass bottles by putting them on the canner, but that is because the glass can absorb heat from the syrup and drop the temp. below where you want it for sterilizing.

I do get some foam in bottles occasionally when filling them too quickly. It depends upon the I.D. of the canner spout I'm using and the size of the bottle. It generally dissipates pretty quickly but on occasion there are one or two glass bottles that still have some foam after a bit. It always dissipates however.

You could try filling the bottles more slowly and see if that changes anything...

[Quebecguy]

[QUOTE=Tweegs;335587]We bottled up 15 gallons yesterday. 5 gallons medium, 10 gallons dark./QUOTE]

In what kind of container and under what kind of conditions was your syrup stored between the time you made it and the time you bottled it?

[Tweegs]

I don’t think air was filtering back in when it cooled, the caps all sealed.

General,

Sterilizing might be a strong word. We rinse the containers with really hot water to be sure there are no flies, ants, spiders, mouse poop, road fumes, cleaning agents, etc. inside.
We can only control what happens to the container once it is in our possession.
What happens between the time the manufacturer packages them and we get our hands on them is anyone’s guess.

I made a fill stop for the wife and it uses a ¼” spout plus ball valve.
Large containers we tip to one side as we start to fill so the syrup runs down the side rather than splashing straight to the bottom.
It’s an attempt to reduce the amount of agitation the syrup suffers.
We can adjust the ball valve when/if necessary.

Quebecguy,

We’re a small op, so we fill 5 gallon SS Cornelius kegs, 1 gallon glass, then retail containers, in that order.
Long term storage is down in a root cellar at about 63* (17C).



We were able to fix it.
We use cone filters off the evaporator, then filter again when hot packing for storage.
After long term storage and prior to bottling we normally run it through a pre-filter only.
Last night we broke everything back down, reheated, then ran it through the pre-filters and an orlon.
No foam this time.

I don’t understand why running it through an orlon would keep it from foaming the way it did previously. Something in the syrup? Niter?? Something else??
Shouldn’t have been, ‘twas filtered twice before.
I don’t know.

[Quebecguy]

Hi Tweegs,
I've given quite a lot of thought to your problem but can't come up with any obvious solution. I'm guessing some kind of contamination of the syrup was causing the foaming. How do you wash your filters? I've had good results by using a dedicated washing machine only used for washing syrup filters. It has never had any soap or other cleaning material (besides hot water!) in it.

[DrTimPerkins]

Were the pre-filters rinsed well prior to using them? Sometimes in the manufacture of textiles they "wash" them. Might be some surfactant or detergent residue.

[Tweegs]

I appreciate it Quebecguy,
We hand wash the filters, hot water only, don’t wring them, hang them to dry.

Orlon filters are replaced annually, the pre-filters get trashed when they are no longer serviceable.

Since the medium we bottled didn’t have the foaming issue, it’s not likely our filters, containers or canning equipment was responsible.

We batch code everything we bulk pack or pack for retail.
We were able to trace back this dark syrup via the batch code.

It was later in the season, sap didn’t really start coming in until about 2 PM, so not enough sap to fire up at days end.
It didn’t freeze that night, sap came in all night long and we awoke to tanks at near capacity.
(My shack is computerized and records temperature data and tank levels, among other things)
We boiled 12 hours that day and the daytime temperature reached 57*.

We had cleaned the pans and tanks 4 days prior to this event and had one short 4 hour boil of raw sap in the interim.
Temps got above freezing (40-ish) 2 days in this 4 day stretch, but for only about 5 hours each day, which accounts for the short boil.

I don’t know what to make of the above.
I don’t see any red flags in our process, but maybe someone else does.
I didn’t note anything out of the ordinary during the boil (i.e. Foaming like crazy!).

I'll check with my wife to see if she was using new pre-filters, Dr. Tim.
It would surprise me if she hadn't washed them prior, she knows better, but there's always that chance.

[Ryan Mahar]

Hey no expert, but I think you have re-activated the sugar sand / niter in the syrup?? I know you did not over-heat but I question if perhaps the syrup you are recanning from, still had niter that was was not properly filtered out initially. When this has happened to me in the past, if you give your bottles a couple days, hold up to the light, you will see the particles floating around that eventually sink to the bottom of the container......is this possible???

[maple maniac65]

In conclusion some syrup when reheated foams and some does not