Taps with anti-microbial materials?

[Maple dabbler]

This is a more academic question. I've been reading about the importance of keeping tap holes clear of bacterial contamination, because once contaminated, production starts to fall off quickly, particularly as temperatures go up in the early spring.

Does anyone know if there have been any studies into using spiles made with anti-microbial coatings, like silver or copper, and whether that has any effect on bacterial growth? Maybe there could even be a spile design that has a slow-release biocide coating which can be reused for a few years. One issue is finding a material that inhibits bacterial growth without killing tree cells in the tap hole. Another issue if using biocide is making sure that no toxic residue makes it into the syrup, considering even a little bit could get concentrated during boiling.

[motowbrowne]

CDL sells the Zap-bac spout with silver in the plastic. Supposed to be good for 3 seasons I think. There's threads on the subject on here. I don't think they're allowed in organic production, and I don't think they have been shown to be as good as new spouts/drops or even CV spouts.

[Maple dabbler]

Interesting. I wonder why they aren't more popular. Also it seems strange that they aren't allowed to be used in organic production considering they only use silver ions.

[30AcreWoods]

If you search around on here, there is a ton of discussion on this topic. There are also studies/publications by UVM and Cornell that go into great detail. CV spouts replaced every year, along with cleaning lines annually and changing drops/tees every few years is generally what the publications say is best. But, you will find folks on here who swear by the Zap-bac, those who feel CV's work best, those who feel CV's don't work, and everything in between. It also makes a difference as to whether you have vac., 3/16" or 5/16" lines/drops, etc., etc. Many variables. My experience this season was: 3/16" gravity with good slope pulling 25-27 in mercury. This was my third season using this setup. I have CV spouts (replaced annually) and I'm on the original drops and tees. Peepers started today, sap went bad today (as usual). I just finished for the year and netted 21.6-gal sap/tap and 0.35-gal syrup/tap. I only rinse my lines with water, but I can say that my sap/tap has been consistent for three years. I'll probably change the drops and tees next year.

[blissville maples]

I think they are pricey, and you don't know how much nano silver is In them. I've heard two years and lightly sand the end to expose fresh silver. I tried some this year, they don't seem to perform bad, but not comparable to new drops.

[DrTimPerkins]

Interesting. I wonder why they aren't more popular. Also it seems strange that they aren't allowed to be used in organic production considering they only use silver ions.

The earliest research (that I can find) on antimicrobial silver in maple production is from the late-1950s. It was not as effective, so was set aside in favor of paraformaldehyde. We started some work on it in the late 2000s and considered filing a patent, but decided against it when we found it wasn't as effective in producing good yields or as cost effective as CV spouts. A few years later a company introduced the ZapBac (and they are still available). They filed a patent application, but it wasn't granted. More info at: https://mapleresearch.org/pub/m0210antimicrobialsilver/

We also looked at and field-tested antimicrobial dropline material (co-extruded inner lining of antimicrobial silver). Works well for high yield (although a good deal of the effect comes simply from putting in a new dropline), but again, it was not cost effective (too expensive) and the effect dropped off too rapidly to be worth doing.

There needs to be more research work done on it. There is some degree of effectiveness for sure, but it is not quite as good as other approaches from an economic perspective. Over a 3-yr rotation it produced an average of 42% improvement in sap yield, with an average net gain of $1.48/tap (see figure).

In terms of organic certification, there is no problem with the silver...it is the "nano" carrier matrix that is the problem.

Lastly, you are correct in that there should be analysis of how much silver it contributes to syrup. To my knowledge this has never been done.

As others have said...some people use them and like them. Some have used them and don't like them. Some have never used them and don't like them. That is pretty much true of anything in maple.

21383

[Sunday Rock Maple]

some people use them and like them. Some have used them and don't like them. Some have never used them and don't like them. That is pretty much true of anything in maple.

21383[/QUOTE]

LOL very well said.

[maple flats]

I used them for 3 seasons now but have decided to go back to disposables when I change my drops for 2021 and then in years 2 and 3 I will use CV2. I likely still have 50-75 on new pre-made drops that will get used but I've decided not to buy more.
If you want to get some feed back from a user of them who has used them for years and uses them exclusively, contact mountainvan, he swears by them.

[Bill Southern NH]

Dave, is there any particular reason that you are going back to the check valves? My wife and I have been using the black check valve adapters for a few years, but this year we switched to the clear ones. We didn't really care for the clear ones because they don't come off of the stubbies very easy. I didn't particularly care for the few black ones that we had out this year because most of them were gummed up when we pulled them. We have tried the zap back adapters on our buckets and they seem to run fairly well. We tried the adapters on our vacuum lines in the past, but they don't really fit well with the leader stubby spouts. We installed all new drops in our one sugar bush this year and have been trying to decide if we should try the one piece zap back and get rid of the stubby, or try another spout, or go back to using the black check valve adapters. We need to replace the drops in our other sugar bush this year, and just trying to decide what we want to try.

Thanks.

Bill

[Maple dabbler]

There needs to be more research work done on it. There is some degree of effectiveness for sure, but it is not quite as good as other approaches from an economic perspective. Over a 3-yr rotation it produced an average of 42% improvement in sap yield, with an average net gain of $1.48/tap (see figure).

In terms of organic certification, there is no problem with the silver...it is the "nano" carrier matrix that is the problem.

Lastly, you are correct in that there should be analysis of how much silver it contributes to syrup. To my knowledge this has never been done.

I was hoping I'd see a response from you. Thanks for the information. I wouldn't expect silver ions to accumulate to any significant degree in finished syrup, since silver compounds are generally insoluble. In any case, I'd expect the silver to be nontoxic to humans. I'd be more concerned if the tap had an organic biocide coating, like that paraformaldehyde.

I'll check out the studies you mentioned. It's exciting that this seems to still be an area of un-settled research.

[Ed R]

Just to be clear maple dabler, the paraformaldehyde was inserted into the tapholes as a pill/pellet and not incorporated into the spout to the best of my knowledge. I doubt the pills would have worked with any type of vac, but they did on gravity.

[blissville maples]

You wouldn't ingest enough silver from this and as stated it is insoluble. There is only one negative health effects from too much silver it's called argyria and turns you a blue hue that's it- no major health issues. I've Ingested colloidal silver a couple drops a day will not harm you. Most people get exposed to too much when they try to manufacture their own colloidal silver incorrectly.


With syrup I am not sure why people are so crazy about consumption. the majority of the population doesn't even consume syrup and those that do aren't drinking cups of it on a regular basis. Silver should not even be a concern.
It just gives " those people" something more to cry about.

Lead is not good but that's gone wild...they should be worried about all the galvanized pipes our schools are plumbed with and the garbage storage tanks lined with pcbs the municipality uses EVERY DAY to supply them!!

[DrTimPerkins]

...In any case, I'd expect the silver to be nontoxic to humans. I'd be more concerned if the tap had an organic biocide coating, like that paraformaldehyde.

Note that I did not say or imply that the silver would reach the level where it would be toxic to humans. That is not the bar that has to be cleared in this case. The issue is that maple syrup is supposed to be pure, and that equipment or materials are not supposed to add anything to the sap or syrup. There is a list of approved materials for maple equipment construction, which does NOT include silver. We know that silver ions are released into sap as part of the antimicrobial process. Does that end up in syrup (not permitted according to the regulations)? Sugar sand (that would be fine)? There are actually a fairly limited number of things that can be "added" to syrup legally...defoamer, filter aid (DE), salt (?), etc. Silver is not on those lists either.

And yes...while paraformaldehyde was definitely NOT a good thing in syrup, it actually DID have an EPA permit for use, so while it was probably not great health-wise from a toxicity viewpoint, it was legal (until 1990 I think) to have formaldehyde residues in syrup. Weird I know...but it was legal. It is the EPA that has jurisdiction on these things (maple producers are protecting an object...the tubing system...not the syrup), not the USDA or FDA.

[Maple dabbler]

And yes...while paraformaldehyde was definitely NOT a good thing in syrup, it actually DID have an EPA permit for use, so while it was probably not great health-wise from a toxicity viewpoint, it was legal (until 1990 I think) to have formaldehyde residues in syrup. Weird I know...but it was legal. It is the EPA that has jurisdiction on these things (maple producers are protecting an object...the tubing system...not the syrup), not the USDA or FDA.

Nice to see that the maple industry isn't immune to arcane rules and government bureaucracy dating back to the 50s, just like every other industry.

Do these things actually get tested for in any "pure maple syrup" that makes it to grocery store shelves?

[DrTimPerkins]

Do these things actually get tested for in any "pure maple syrup" that makes it to grocery store shelves?

In general that is not the way things work in the food industry. Testing is only done for specific foods and for specific contaminants if problems occur, or if there are known issues (ie, lead in maple, mercury in fish, etc.). There is some testing for "common" contaminants of concern periodically, but not as a general thing. The cost to test everything for every possible contaminant would be astronomical (even in governmental terms).