Economics of changing spouts

[MainelyMaple]

Wondering if anyone can direct me to any information or study that shows how much better a new tap will perform over a 2nd year tap or older. I have 700 taps, about half of them are the CDL clear seasonal spouts that were new last year, and the other half are 2-3 year old health spouts. I'm definitely changing the older taps but trying to justify changing the seasonals. Wondering if I can get one more year out of them. I understand they perform better when they are new but how much better? At a local CDL seminar this past weekend they claimed 25% increase in production with new taps, but no study to back it up. If it is in fact that much of an increase then obviously its a no brainer. I mean with 700 taps your talking over a $2000 return on a $120 investment (speaking averages of course). I'd just like to see something to back it up. And if that is unrealistic then what can I realistically expect to see from new taps. I get that they perform better, and I get that they are priced so cheap so they can be replaced every year, but is the gain enough to justify the time and money spent every single year on a smaller operation like mine. Thanks for any input

[SWEETER CREATIONS]

We had 160 taps that were 5 years old and put another 160 in a new woods the new ran 50 % better than the 5 year old taps. You have to be the judge on your end but for me that's how they performed
With the check valves now they get changed them every year..
When we bought check valves they told me I didn't need them on a new system but I figured the tree still froze and thawed so I spent the extra and glad I did as the pumps ran non stop for 12 days.
Good luck.

[Mark-NH]

You answered your own question in a way. $120 for new taps. That's 120 gallons of sap. You don't need much increase per tap to justify that expense. Certainly considering how much $ you have invested elsewhere.

[DrTimPerkins]

Very glad to see people actually thinking about this in economic terms. The goal should be to put the highest amount of $ in your pocket, and not necessarily just how much sap you produce.

25% is probably a little on the high side. It's been pretty well established that you'll lose somewhere between 15-20% in the first season (and the sap yield loss continues to drop for at least 5-6 years). By replacing your spout each year, you'll recapture some of that (but not all). On average you will realize a net profit (small cost, modest gain). By using CV spouts you'll recapture considerably more of that loss, at a slightly higher cost, but typically with a higher net profit than using new spouts alone. By putting in new drop lines and spouts, you will realize the largest sap yield increase, but the cost of getting that extra bit of sap is fairly high (especially when you include labor cost to make and install the new drop). So you'll end up with more sap, but if you replace drops each year, you would typically you'll end up with a slight net loss. If you replaced drop lines last year you probably lost money on it.

Bottom line....definitely replace your spouts each year. For a lower cost you can use any seasonal spout and get a slight net profit. Use CV spouts at a slightly higher cost and get a higher net profit.

I'm working on a spreadsheet (and graph) to show those relationships in a pretty simple way. Hope to have it done in a couple of weeks.

[Greenwich Maple Man]

Wondering if anyone can direct me to any information or study that shows how much better a new tap will perform over a 2nd year tap or older. I have 700 taps, about half of them are the CDL clear seasonal spouts that were new last year, and the other half are 2-3 year old health spouts. I'm definitely changing the older taps but trying to justify changing the seasonals. Wondering if I can get one more year out of them. I understand they perform better when they are new but how much better? At a local CDL seminar this past weekend they claimed 25% increase in production with new taps, but no study to back it up. If it is in fact that much of an increase then obviously its a no brainer. I mean with 700 taps your talking over a $2000 return on a $120 investment (speaking averages of course). I'd just like to see something to back it up. And if that is unrealistic then what can I realistically expect to see from new taps. I get that they perform better, and I get that they are priced so cheap so they can be replaced every year, but is the gain enough to justify the time and money spent every single year on a smaller operation like mine. Thanks for any input

I never drill a hole now and not put in a new spout. The payback is well worth it. What tap to use is a big question now. There are so many on the market these days and new ones being developed all the time.Everybody will "claim " that they have the "best" one.You don't know till you try it. I've tried quite a few and have found that hands down the CDL Smart Spout has been the best so far in my operation. I like the design very much and the output is great. Thats all I use now .

[FunnyFarm]

Would there be any benefit to gathering in all taps at the end of each season washing and sanitizing(boiling) them instead of purchasing new? Or does the tap become spoiled after each years use never to bacteria free again?

[snox243]

i have just started using seasonal spouts this is my 2nd year with them. ill let u know after season how it goes

[TerryEspo]

I second that question about collection all taps, boiling and then reinstalling them.
I ask becuase I bought a hundred drops from someone who removed them. This will be my second year to use them. I boil them before useing them. It is not too late for me though to buy new taps, I can get them ASAP .

Should I be buying new taps ?

Thanks.

Terry

[ennismaple]

FunnyFarm and Terry,

Boiling plastic spouts does not get rid of the biofilm because plastic is porous. This means you cannot sterilize them and make them produce as much sap as new spouts. Dr Tim has posted numbers to support this in the past. We tried this for a few years but didn't see much benefit. Once we went to all new spouts every year we saw a significant increase in production per tap!

[MainelyMaple]

It's been pretty well established that you'll lose somewhere between 15-20% in the first season (and the sap yield loss continues to drop for at least 5-6 years).

So 15-20% loss of production after year one with a brand new tubing system? You don't have a graph that shows that info do you? I'd be curious as to how much yearly loss after year one (I assume it's not quite as drastic?) and how much total loss after 5-6 years. Once I know this info I can use it to run numbers and see what's suitable for my operation. How often to replace spouts,drops,tubing, etc..

Great info as always Dr. Tim. Thanks for the input everyone.

[unc23win]

Boiling plastic spouts does not get rid of the biofilm because plastic is porous.

So in the case of the Check Valves does this mean the plastic part before the check valve? Is that why changing them every year works?

MainlyMaple Dr Tim said "I'm working on a spreadsheet (and graph) to show those relationships in a pretty simple way. Hope to have it done in a couple of weeks."

[DrTimPerkins]

You don't have a graph that shows that info do you?

Why yes I do have exactly that....representing about 6 yrs worth of work. It was published in the Maple Digest a few years ago. These relationships and calculations are based upon a tubing system that had been washed each year with air/water. http://www.uvm.edu/~pmrc/aging.pdf See Figure 4. All of the treatments were replicated 3 times, so these numbers are pretty solid averages.

About a year after that CDL had a similar chart from Centre Acer in their catalog showing about a 17% reduction after 1 season (which was probably done with tubing systems that had been washed with isopropyl alcohol, as is common in Quebec), so we're all in the same ballpark as far as numbers are concerned (hence my statement that 25% in one year was probably a bit too high). The suggestion was that by replacing droplines you could recapture that lost sap. That provides a good case for a useful illustration right there. Let's assume if you replaced drops (tee, tubing, adapter) that you could get sap yield back up to 100% (probably close, but not quite). Let's also assume you're doing a good job, and making 20 gal of sap per tap. So the loss of 17% of your sap equals a loss of 3.4 gal of sap. Assume sap is worth $0.50 per gal, so about $1.70 worth of sap. Great....let's also assume you can recapture that loss by installing a new drop line EACH YEAR (maybe close, but not quite). Problem is...what does it cost you to get that sap. I don't have a catalog here in front of me, but Ithink it's about $0.35 for a tee, $0.30 for a 3' piece of tubing, and $0.15 for an adapter, total of about $0.80. It costs about $0.20 in labor to make it, and about $0.60 in labor to install it in the woods, and about another $0.20 to buy the supplies and dispose (recycle) the waste. So you're looking at an extimated cost of about $1.80 per drop. Yes, we can argue about the actual cost of sap (which varies from place-to-place and by sugar content), the actual cost of parts, labor, whatever...but in general these are in the ballpark more or less. So now, you remove the cost of that $1.80 drop from your $1.70 sap value gained, and you've got a net profit of MINUS $0.10 per tap.....in other words, you got more sap, but you lost money doing it. Replacing drops each year does not appear to be a cost-effective way to produce profits that go into your (the producer's) pockets. Now maybe you're a one-man show and don't factor in your labor, but then again you might have 50,000 taps and have to hire people to do some of the work.

So, knowing this thread would continue, I got a lot done on the spreadsheet today.....still some fine-tuning to do, but the above example is the basics of how it works. It starts out with a brand-new system. In then calculates the sap produced from employing different strategies in the following years as the system ages. Different strategies include: using a new spout or spout adapter each year, replacing drops (tee, tubing, adapter) each year, using a new Check-valve spout each year, or using a new spout or adapter for the first couple of years, then replacement of the drop in year 4 (so a 3-yr drop replacement interval), followed by the continued use of a new adapter the next few years. It then calculates the expected net profit increase over NOT doing anything (sap produced x $0.50/gal - cost of using that strategy - value of sap if you did nothing). Obviously the net profit in year 1 is the same (all starting from the same point, new tubing system, new adapters). The bottom line over the next 5 yrs under that scenario is:

Net profit increase (above that gained by doing nothing -- no replacement) over a 5 yr period
Replacement of spouts or adapters annually (minus cost of spout adapter each year) = $3.31 ($0.66/yr)
Replacement of drops (including cost of tee, tubing, spout, labor to make it and install it) = $2.70 ($0.54/yr)
Use of new Check-valves annually (minus cost of CV each year) = $8.33 ($1.67)
Use of new adapters each year, replacement of drops in Yr 4 (minus cost) = $5.72 ($1.14)

This is for a producer with a baseline production of 20 gal of sap per tap, on vacuum.

The graphs aren't quite ready yet, but I think this is what you are trying to accomplish in your calculations. My personal opinion is that is the way everyone should look at this issue, and that by understanding the costs, the effects on yields, and the effect on net profit, maple producers can make better informed decisions on the management strategy they wish to use in their operation. Hope this helps. Once the spreadsheet and graphs are done, I'll probably publish it in the Maple Digest and put it on our website. If anyone has any suggestions on how to improve it, or wishes other scenario run, let me know (however NO....I'm not going to run 500 different individualized scenarios...just common ones).

[Mark-NH]

Dr. Tim,

I really enjoy reading your input. Question for you; you said replacing drops was a negative gain in a paragraph yet you showed it as a small net gain in your formula. What am I misinterpreting?

[DrTimPerkins]

Changing drops EVERY year would normally be a slight loss in the first year. In subsequent years, it'll creep into positive, because the "do nothing" continues to drop, the difference in sap yield goes up. It isn't as simple a formula as you might first assume.

[FunnyFarm]

Sorry just looking for a short answer on this...So as i read changing spouts every year and drops every 3rd year or so seems to be about the standard?

[DrTimPerkins]

Sorry just looking for a short answer on this

That's almost an impossible request to ask of a scientist. :D


....changing spouts every year and drops every 3rd year or so seems to be about the standard?

Not sure there is concensus yet on a standard, but if you are using 5/16" plastic spouts on vacuum, then changing them every year is definitely recommended. If you aren't using the CV spout, then changing drops every 3-5 yrs would be helpful (although the economics of this are highly variable based upon the season you do it in -- if you changed droplines last year you probably lost money on it no matter how old the previous drops were). If you're using CV spouts, no need to change droplines unless they are damaged or REALLY old (like PVC tubing or extremely dirty for some reason).

[Amber Gold]

Talking about sap yields, have any studies been done on sap yields from 1/4" vs. 5/16" spouts? If we're using high vac. (or vac. at all) we're able to draw sap horizontally around the tree, so do we need the larger spout? From what I've heard, the 1/4" spouts have the same size opening as the 5/16" spouts, so there wouldn't be a restriction there. A 1/4" hole is about a 1/3 smaller than a 5/16", so I'd assume the healing time would be significantly increased, and the staining would be decreased. I'm not using this to justify tapping smaller trees, just wounding the trees I am tapping less, but still getting comparable sap yields.

[DrTimPerkins]

Talking about sap yields, have any studies been done on sap yields from 1/4" vs. 5/16" spouts?

There haven't been a lot of studies, but those I've seen indicate that there is some sap slight amount loss with a 1/4" spout compared to a 5/16" spout. The 5/16" spout is sort of at the "sweet spot" for maximizing sap yield while minimizing wounding. Additionally, the 1/4" spout was not introduced as a way to produce sap while reducing wounding.....it was first introduced when syrup prices spiked to $4.00/lb and some equipment manufacturers came up with the idea of tapping in the fall with 1/4" spouts and reaming to 5/16" spouts in the spring. Didn't work out very well (you lose sap production in the spring). So now, at least in my opinion, the 1/4" spout is a spout that is still around and just looking for a reason to exist. The companies all made their molds, which costs a pile of $ to produce, so they'd like to sell enough of the 1/4" spouts to justify making the mold.

So the question you might ask about these types of new products is: show me the data/results that show they work. If there are no results, there haven't been any studies. Too many times things are tossed out there for maple producers to buy with absolutely NO testing at all. Buyer beware.

[Amber Gold]

Thanks Dr. Tim

[DrTimPerkins]

OK....I've finished the spreadsheet to my satisfaction. It was actually a rather fun and interesting exercise, as it pulls together a lot of information we have learned in the past decade. I'll give the quick summary.

It is important to recognize that these calculations are based upon a lot of research, most of it at the UVM Proctor Maple Research Center, but also work done by the Cornell Maple Program and Centre Acer. Most of the general patterns are described in http://www.uvm.edu/~pmrc/aging.pdf The systems all assume you start out exactly the same with identical, brand-new tubing installations. This scenario is for a vacuum tubing system. It assumes a yield of 20 gal sap/tap in the first year on that new system (your mileage may vary), and then calculates losses or gains in sap, costs, and net profit based upon the implementation of various replacement strategies over a 5 yr period after initial installation, again, based upon the results of many years of research. There are no guarantees you will achieve these exact results, as unusual events, such as the weather we experienced last season, or equipment failures, lack of good vacuum, etc. may result in considerable variation. These are generalized patterns....we cannot predict for all the eventualities that might occur.

The replacement strategies (and estimated costs) investigated were:
1) annual replacement of spouts (seasonal spouts) or spout adapters $0.16
2) annual replacement with CV spout adapters or CV spouts $0.38 (mid-way cost between the original and new version of the CV spout)
3) replacement of drops at various intervals, including:
1 yr (annually), 2 yr (every other year), 3 yr, 4 yr, and 5 yr. $1.80 for dropline material and installation (including labor)

The value of sap was placed at $0.50 per gallon. Results are shown in net profit gain AFTER the cost of the implementing a particular strategy.

A change in any of those variables will alter the results to various degrees.

Results (net profit gain achieved over no replacement) are average $ per tap per year (5 Yr total showin in parentheses)

1. Spout annual replacement = $0.66 ($3.31)
2. CV use with annual replacement = $1.67 ($8.33)
3. Drop replacement
1 Yr = $0.54 ($2.70)
2 Yr = $1.14 ($5.72)
3 Yr = $1.14 ($5.72)
4 Yr = $1.05 ($5.24)
5 Yr = $0.78 ($3.91)

We still need to know how cleaning affects the overall economics of these calculations. My suspicion is that it will raise the level of the "do nothing" baseline some amount, which will reduce the net profit of employing any replacement strategies to some degree. How much remains to be seen. In addition, there is a "cost" to cleaning that will need to be measured and factored in. Also, I'd like to eventually make this into some type of on-line calculator so people could use it to enter their own numbers for things like current age of tubing system, materials cost, sap value, baseline sap yield. Maybe a version for gravity as well. That is going to take some time.

I expect to write this up and submit it for an upcoming Maple Digest article for publication this year.

[ennismaple]

Thanks Dr Tim - great info!

[unc23win]

Yes indeed very good info. I just might take the your calculations and plug them into excel to see what I might accomplish. Although I am expanding so much each year its hard to see increases or decreases related to age of tubing and such, but still very good to know. Thanks

[not_for_sale]

Has anyone tried to sanitize with uv in addition to hating the spout? Such as this: http://www.amazon.com/Salon-Combination-Sterilizer-Warmer-Cabinet/dp/B004CN8XZU/ref=sr_1_11?ie=UTF8&qid=1360365557&sr=8-11&keywords=uv+sterilizers

[happy thoughts]

Has anyone tried to sanitize with uv in addition to hating the spout? Such as this: http://www.amazon.com/Salon-Combination-Sterilizer-Warmer-Cabinet/dp/B004CN8XZU/ref=sr_1_11?ie=UTF8&qid=1360365557&sr=8-11&keywords=uv+sterilizers

I don't see how that would work at all. In fact I don't see how they can even claim to disinfect towels given that the size of the unit looks pretty small. At best it will only disinfect the exposed surface where the UV light can reach. The spouts being discussed here are generally opaque and the UV light has to be able to reach the interior surface in order to disinfect. Even when used in water purefication, UV effectiveness is hindered with increased water turbidity. If the UV light can't reach the microbes, it's not going to disinfect. Any biofilm on the interior spout surface would also decrease effectiveness. Considering the low cost of these spouts imho you'd be better off just replacing them.

[DrTimPerkins]

Has anyone tried to sanitize with uv in addition to hating the spout?

It wouldn't work since you wouldn't be able to reach the inside of the spout and all the nooks and crannies. Doesn't matter a great deal if the outside is clean, matters more what is on the inside.

[TunbridgeDave]

Doesn't boiling work?

[Thompson's Tree Farm]

No, boiling does not work!

[mustanger]

What does kill the microbes or whatever they are? Surely something kills the critters. Heat? Dry? Some disenfectant? I ask this to try to understand what we are dealing with.

[FunnyFarm]

To be honest the thought of tossing away taps every year bothers me.The thought of every one of us tossing away taps every year truly bothers me...Since I've moved to my farm I've constructed 3 buildings...All with salvaged lumber. I restore old falling down barns for a living. I truly believe in recycling and reusing. A huge part of the person I am and the way I've chose to live my life, making syrup is part of that is to live more in balance..In tune with nature.
That being said if it truly makes sense to toss them every year then it's what I'll do. Maybe though we should look for some way in which we can have it all...does stainless clean up better? Doesn't copper have antimicrobial elements? Is there any way we can avoid throwing a few ton of plastic away every year? A recycling program? If in the end it is what it is so be it. I'm just curious if any other options exist...The landfill already has enough trash...

[Thompson's Tree Farm]

I don't like throwing plastic either. I bring all the "throw aways" to the house and recycle them. Same for used tubing. As for a way to kill the bacteria, there doesn't seem to be one that meets FDA approval. In Quebec they use an alcohol solution that is left in droplines to soak for an extended period and then rinsed out but that is not approved here. My understanding is that preliminary trial results at Cornell indicated that a hot oil soak (500*F) did seem to work but more followup testing is needed.

[TunbridgeDave]

How about this? The melting point of polycarbonates is around 160C or 320F. The dry-heat method of sterilization requires 2 hrs at that temp. You could do it while cooking dinner LOL!

[Amber Gold]

If we're going through all this effort to re-use spouts, are we saving any money for the time we're putting into it, and are the actual costs more than the energy cost required to clean spouts. Since they're only ~$0.30/ea, probably not.

I do agree it's a huge waste, but wonder if it's time/money well spent.

[DrTimPerkins]

I do agree it's a huge waste, ...

Studies to date looking at various types of cleaning are inconclusive. While there can be some improvement, the results will not match those of replacement. It isn't hard to remove a good deal of the microbes, but in most cases, totally eradicating them takes extreme effort (and/or cost). Most studies to date show that the best approach (in terms of sap yield) is replacement. However as I've said, it is also important to look at the economics of what it takes to get that sap. Total replacement of lateral lines, droplines, spouts and fittings EVERY year would produce the highest yields, but would deplete your wallet pretty quickly. What our work is aimed at doing is finding strategies that both produce results, and produce profits to put into your wallet. There is always the alternative to spend no money and do nothing, with the consequences that you will have low sap yields. If that works for you, fine. If you want more profits, then figure out what will work best for you, spend the money to do it, and realize the benefits. None of these are guaranteed though.....like all things in agriculture, it can seem like a crapshoot at times, and things can go wrong (like the 2012 season).

Perhaps at some point a cleaning and sanitation regime that works well can be identified. At this stage though, replacement appears to be the best approach, and can be the way to realize higher profits.

Replacement need not be wasteful if the tubing and fittings are recycled.

[lastwoodsman]

After all the investment changing of the spouts for me is the cheapest part. This past week-end and it coming up on my second year of real licensed production. I changed out all my gravity lines with new replacement CDL smart spouts and on the vacuum I went to all CV's of course for me I only have 150 on vacuum. But after last years snot plugging the spouts I figure I got 5 years worth of the bacteria in a week, nasty, nasty stuff last yr.

[FunnyFarm]

Have any studies been done using copper taps? I've looked and not actually found any commercially made copper taps but if one were to figure the cost of 1/4" copper tubing at about $15 for 10'...That would produce 60 taps at a cost of app. 50 cents a tap(accounting for $15.00 per hr. labor) Now some would say that the labor could be done while watching a movie or sitting round or paying $8 an hour to the help...anyhow if the copper with its natural antimicrobial aspect came in at a max of 50 cents a tap it might just be the answer...

[GeneralStark]

What do people think of the new CDL Spout with the alcohol sanitation cup that you plug the spout into at the end of the season? IT appears that the idea behind this is that the spout and drop will become "sanitized" by the alcohol cup during the off season. I believe you would also pull spouts under vacuum and therefore the alcohol vapor would be introduced to the drop and lateral.

I suspect this has been tested/studied at Acer but I haven't found any results.

[Tweegs]

1. Spout annual replacement = $0.66 ($3.31)
2. CV use with annual replacement = $1.67 ($8.33)
3. Drop replacement
1 Yr = $0.54 ($2.70)
2 Yr = $1.14 ($5.72)
3 Yr = $1.14 ($5.72)
4 Yr = $1.05 ($5.24)
5 Yr = $0.78 ($3.91)



Good info Dr. Tim.

I’m curios on drop replacement though.
Changing the drops at 2 to 3 years seems to be of greatest benefit, but at years 4 and 5 the overall benefit is reduced from the do nothing approach.

I’ll make an assumption then that the lateral is in such poor shape at 5 years old that it marginalizes the drop replacement. If so, it would make sense to replace the drops every other year, and the laterals at 4 years, based on the numbers above, to maintain a good cost vs. production relationship.

Is that correct?

[Scribner's Mountain Maple]

Dr Tim,

First Thank you for this information. My question is about the cost of the drop and spout for seasonal spouts vs CV. For me, a "T" and 3 ' of line is between 60-70 cents. Add 30 cents of labor and get $1. With the CV, you have the cost of the stubby which is another 30 cents +/-. Does the cost of this additional piece, combined with the +/- 25 Cent increase in each tap, increase production enough to justify the CV vs the seasonal?

For example lets say you change the drop-line once in a five year period, so that would be the cost of one new drop and one replacement. At my estimate of $1.00 per drop-line when using a seasonal spout and my estimate + 30 cents for stubby or $1.30 per drop for CV.

For 1000 taps over 5 year period where drops are replaced once and taps are annually replaced.
Seasonal drops - $2000 (2*$1,000)
Seasonal taps - at 15 cents apiece - $750 ($150 * 5)

for CV -
Drops - $2600 (2 *$1,300)
CV taps - (using .38 per tap) $1,900 - ($380 * 5)

Total over 5 year for seasonal being $2750

Total for CV being $4,500.

Difference - $1750 per 1000 taps. at your 50 cents a gallon price, that would mean you would need to produce 3500 extra gallons of sap, or 3.5 gal per tap more with a CV to equal a seasonal spout.

Yes my math is fuzzy and estimated.

So I guess my final question is this. Does a CV increase sap production by 3.5 gal per tap annually to justify it's extra cost?

Thanks

[DrTimPerkins]

6687
Changing the drops at 2 to 3 years seems to be of greatest benefit, but at years 4 and 5 the overall benefit is reduced from the do nothing approach.

Not sure where you are getting that from (Yrs 4-5 overall benefit reduced from do nothing). "Do nothing" is the baseline condition.


I’ll make an assumption then that the lateral is in such poor shape at 5 years old that it marginalizes the drop replacement. If so, it would make sense to replace the drops every other year, and the laterals at 4 years, based on the numbers above, to maintain a good cost vs. production relationship.

No. For the majority of scenarios, if you aren't going to or don't want to use CV adapters, then it makes the most economic sense to change droplines every 3rd year (and change spouts on those droplines every year). There is some variation depending upon what the baseline conditions are (how much sap you "could" make given your tubing setup and vacuum, cost of implementing each strategy -- and cost of labor, and the value of the sap produced). If you want to save yourself a little work, changing droplines every 4th year doesn't result in much of a loss (from the baseline compared to 3 yr replacement).

Lateral lines do have some influence on contamination in the taphole, but it is very slight. Some of our recent publications address the influence of all the parts of the system (spout, drop, lateral lines, mainlines) on sap yield as they age. I don't see any real need to replace droplines until you've reached the end of the useful life of the materials (10-20 yrs). The cost of replacing laterals, especially if you include labor, would be prohibitive.

In general, high sap value, low drop cost, and high baseline yield tend to drive the model towards earlier replacement of drops (but it is almost never economically advantageous to replace drops each year), whereas low sap value, high drop cost, and low baseline yield tend to drive the model towards less frequent dropline replacement intervals. The most profitable estimated dropline replacement at a 3-yr interval, based upon about 85 different model-run scenarios. All of these are estimates only, based upon what we've learned over the past 10 yrs. Any one year can be a real fluke -- like 2012, when all these calculations go out the window. If you replaced droplines for the 2012 season, you probably lost money.

If you're using CV adapters or the CV spout, replacing the dropline has negligible effects even 10 yrs out.

I've attached a graph summarizing those results. It will be part of paper I'm writing for Maple Digest, but probably won't come out until late this summer or early-fall. Hopefully we can manage to also have a webpage where people can go and plug in the numbers for their own situation and see what happens to the economics of their operation if they make selected changes.


Is that correct?

No.

[Tweegs]

Not sure where you are getting that from (Yrs 4-5 overall benefit reduced from do nothing). "Do nothing" is the baseline condition.



Poor wording on my part. What I tripped over is why drop replacement at year 3 was worth $1.14 and at year 5 only $0.78, couldn’t get my mind around that without something else playing a role, but I get it now.

This thing called work, and all its distractions…missed a couple of key points made earlier, and your recent post cleared up even more.

I’m all caught up now, thanks!

[DrTimPerkins]

Poor wording on my part. What I tripped over is why drop replacement at year 3 was worth $1.14 and at year 5 only $0.78,...

Ah....I see the problem. Those results were NOT what happened each year in time-series after replacement, they are what happens with dropline replacement at that time interval (every year, every 2nd year, every 3rd year....). Those numbers are estimated average annual net profits (averaged over a 5-yr period) above what you would get doing nothing.

[DrTimPerkins]

for CV -
Drops - $2600 (2 *$1,300)
CV taps - (using .38 per tap) $1,900 - ($380 * 5)


This section of your math is very fuzzy. I've said you don't need replace your droplines with CV spouts or adapters (the benefit is marginal). So you can subtract off $1,300 immediately. I've also normally said that any benefit of a CV spout or adapter on a brand new tubing system is marginal, so you need to back out another $380, but add in your $150 to accout for seasonals the first year, so the net is -$230.

So the difference is now down to $220. We'll ignore the fact that most seasonal spouts are around $0.18-0.19, unless you go with a straight-style seasonal (not nearly as popular), which would up your price by $0.30 (but I'll let that slide). You also overestimated the cost of the Leader Stubby by $0.01 and the CV spout adapter by $0.03. It's not a lot, but these are hard numbers we can easily get, so it adds up to $40. So we're down to $180 difference (seasonals still ahead). You did include labor to make the spout, at $0.30 (we done some studies and estimate that at $0.20). However you neglected to add in the cost of bringing the drops out to the woods, installing them, and removing the old drops, which is more labor intensive than just making them. Our estimates for that are $0.60 per drop (conservatively). So we need to subtract out another $0.60 per drop for the seasonals, which amounts to $600. Now you're down to -$420 (negative profit) to begin with before you start to collect any sap. So overall, it's actually already cost you more to change your drops in a 5-yr rotation than to use CV spouts. New drops will (in the first year) produce slightly better than CV spouts, but you lose that benefit by the 2nd year, and they cost you more to start with.

Second part of your question was:

Does a CV increase sap production by 3.5 gal per tap annually to justify it's extra cost?

As you can see above, you no longer need to produce 3.5 gal/tap more. You could actually produce somewhat less sap using CV and still put more money in your pocket. That is kind of what I've been saying all along. You shouldn't look just at the total sap yield, but what it costs you to get that, and most importantly, what is your anticipated or expected net profit (or loss) from making any type of management decision.

The average of 28 different studies done by UVM PMRC, Cornell Maple Program, and Centre Acer is a 6.5 gal/tap gain using CV. Of course, the conditions (age of dropline, age of spout) you are comparing it to will greatly influence those results, and admittedly, some of those studies compare old spouts on OLD drops to new CV on OLD drops.

When we (and other research centers) have done head-to-head comparisons (same age dropline, NEW CV vs NEW spout), a new CV averages a 13.66% increase, which comes to about 2.7 gal/tap when compared to a regular NEW spout under identical conditions (or at least as close as we can get it). The range in increase is from 0% (for a study done by Centre Acer....although the same study in same year in another site found a 19.6% increase) to 31.7%. Our studies at UVM PMRC range from 4.7% (in 2012) to 31.7% (in 2011). Typically a decent season that doesn't end abruptly due to extremely hot weather has a big increase, whereas a year like last year has a smaller increase.

Going back to your original scenario.....using new seasonals each year with new drops every 5th year, you end up with an average annual net profit (averaged over the succeeding 5 seasons from your base year) of:

New drop Yr 1, new seasonals each year = $0.39/tap (no drop replacement)
New drop Yr 1, new seasonals each yr, new drop in Yr 5 = $0.53/tap (5 Yr drop replacement interval)

So drop replacement definitely can improve profits (if done correctly). But it turns out you'd actually do better economically with:

New drop Yr 1, new seasonals each yr, new drop in Yr 3 = $0.78/tap (3 Yr drop replacement interval)

However when you compare those scenarios to using CV spouts:

New drop with seasonal spout in Yr 1, new CV each year (polycarb version) = $1.03/tap (no drop replacement)
New drop with stubby and regular adapter in Yr 1, new CV adapter each year after = $1.02/tap (no drop replacement)

These scenarios all assume sap value of $0.35/gal and a base production of 20 gal sap/tap. Actual numbers will change a little if you alter the initial assumptions, but the overall patterns remain similar.

The only scenario that comes close to economically matching the use of CV spouts would be achieved only if you discount all drop labor costs (both making the drops and installing them), you replace drops EVERY year, you have very high sap production (30+ gal/tap per year), and your sap is valued at $0.50/gal or more. Not a terribly realistic scenario for most producers.

[DrTimPerkins]

Have any studies been done using copper taps? I've looked and not actually found any commercially made copper taps but if one were to figure the cost of 1/4" copper tubing at about $15 for 10'...That would produce 60 taps at a cost of app. 50 cents a tap(accounting for $15.00 per hr. labor) Now some would say that the labor could be done while watching a movie or sitting round or paying $8 an hour to the help...anyhow if the copper with its natural antimicrobial aspect came in at a max of 50 cents a tap it might just be the answer...

So this is based upon the premise that some metals have anti-microbial properties (silver and copper being the most common). Unfortunately, pure metallic copper or silver will tarnish over very quickly, or will be covered in microbial biofilms. In addition, the surface area isn't super high while the microbial level in sap can be quite high. Thus the approach towards using oligodynamic metals is to make fine nano-scale granules and mix it into the plastic.

There are silver spouts made. We experimented with this before that product came out. We found that the silver spouts worked one year and then the effectiveness was gone. Steve Childs (Cornell Maple Program) has done some work with the actual product and found that he could restore some of the effectiveness by running a bore brush on a drill through the spouts each year. They're expensive, but the manufacturer claims they'll last 5 yrs. They haven't been out that long, so no idea where that number comes from (once again, like so many products in maple....ask to see the research and "buyer beware").

To my knowledge, nobody has looked at how much silver or copper leaches from these things and how much is concentrated in the syrup. In addition, you cannot use these types of spouts if you're organic (they don't object to the silver....but they do object to the "nano" ceramic carrier material).

[FunnyFarm]

Thanks for the reply. Much appreciated. So back to plastic and figuring the best rotation. Seems using cv's and not replacing drops is the way to go though. Still not happy about tossing all the plastic but so it goes.

[Scribner's Mountain Maple]

Thank you for the answer and explanation. I guess it is time to bite the bullet and switch to CV. Next year I guess as I have already purchased my seasonal straight spouts (15 cents each) for my bush. I have hesitated to make the switch because my vacuum maxes out at 18". Is it true you need 20-22+ for CV?

[Thompson's Tree Farm]

Thank you for the answer and explanation. I guess it is time to bite the bullet and switch to CV. Next year I guess as I have already purchased my seasonal straight spouts (15 cents each) for my bush. I have hesitated to make the switch because my vacuum maxes out at 18". Is it true you need 20-22+ for CV?

No, Cornell tests show an increase using CV's even without vacuum. You will still get a significant increase at a lower vacuum level.

[Scribner's Mountain Maple]

Great, that is good to know. 2014 I am making the switch to CV. There is no arguing with the economics.

[DrTimPerkins]

Is it true you need 20-22+ for CV?

No. The higher your vacuum the higher your yield, but CVs will work fine at that vacuum level.

[ennismaple]

However when you compare those scenarios to using CV spouts:

New drop with seasonal spout in Yr 1, new CV each year (polycarb version) = $1.03/tap (no drop replacement)
New drop with stubby and regular adapter in Yr 1, new CV adapter each year after = $1.02/tap (no drop replacement)

You just made our decision making easy Dr Tim. We added 400 new taps on new laterals and mainlines this year and we were not sure if we should use regular seasonal adapters on the stubbies or CV's. Regular adapters it is this year! This also reinforces our decision to use stubbies and CV's instead of CV2's because the 1 cent per year benefit isn't worth it compared to the extra labour to cut off the CV2's.

Thanks for all the data! Numbers don't lie...