Sap Yield vs. Vac. level

[Amber Gold]

How much of a difference in sap yield is there between 18-19" vac. levels and high vac. levels of 25-28"?

Thanks

[ennismaple]

A lot. I've read that every inch of Hg above 20" increases your sap yield by 5%.

[Amber Gold]

Does it say how much your sugar content goes down as a result of the higher vac?

[DS Maple]

Personally, I'd like to see a graph of sap yield vs vacuum. I think it would have to plane off eventually. I talked to a guy pulling 25" on 25,000 taps and he wanted to achieve 27" not for sap yield, but because his pumps ran more efficiently at higher vac as a result of moving less air. For the small producer this probably wouldn't be too important, but this guy was running twin 20hp electic motors.

[Haynes Forest Products]

Everything works better the releaser the seals on a vacuum tank the tap holes leak less.

[gmcooper]

Proctor Maple research has some data on production at various vacuum levels. If I remember correctly it also gave sugar % which did not change much if any.

[brookledge]

The one thing I'd also recommend when going to high vac. is reduce the number of taps per tree. When Procter did there study I believe they only had one tap per tree.
Other wise I'd say that for every inch higher you gain volume and the sugar content remains fairly steady.
http://www.uvm.edu/~pmrc/
Click on Vac. sap colection on the right side. The graph shows the higher the vac the more sap.

[Amber Gold]

Thanks Keith. I set up my tubing for vac. and kepth all but a couple of laterals to the 5-7 range. I'm going to rework some of it this summer to eliminate some long lat's with more than 7 trees by running a mainlines over to the trees. It looks like it'd be cost effective to go LR and pull greater than 20" to get the additional sap yield. Surprised to see sugar content wasn't really effected.

[maplecrest]

in my new woods this year i ran 4 per lat.

[Russell Lampron]

I think what Kieth was saying is to reduce the amount of taps per tree if you have more than 1 per tree now.

[brookledge]

Yes I was refering to reducing the taps per tree. As I stated I believe that those test where done with one tap per tree regardless of the diameter. If you have trees with 2-4 taps in them and go to high vac. like 25" you will not get as much sap per tap as if you only had one tap per tree.
I'm planning on replacing my vac pump and getting a liquid ring eventually. I set up a new main line with high vac. in mind and believe me it was hard to keep telling myself "that's enough taps on that tree" . Many trees that I would not even think twice on throwing two taps into I intern put only one in.
Keith

[pelz]

http://www.uvm.edu/~pmrc/vacsap.pdf

[Jeff E]

Vacuum at the tap is greatly effected by length of the lateral and the slope of the lateral. In pulling taps and checking vac, if I had a long lateral, say 120 ft with a sag in it, the vac was way down.

I will be redoing some areas as well to make sure I dont have any runs over 100' and most importantly I have tight lines with no up slope from sagging.

[caseyssugarshack93]

i had a hard time getting used to putting in one tap per tree too i was putting 2 in like 18-24 inch trees at first then i talked to people with vac and said one tap per tree is best with vac so one line i kinda messed up on and over tapped but the other 2 i put one tap per tree which i acully feel better doing that then worrying about over tapping

[Amber Gold]

I didn't abide by the one tap per tree rule. Why does it make such a difference? Isn't the vac. only pulling sap from an area approximately the same size as gravity? This year I managed over 16 gal per tap, and that's with not being very good about turning the vac. on first thing in the morning, having overflowing tanks, and pulling them a week early. I'm pretty confident I would've pulled in 18-20 gpt if I collected everything.

After walking through my woods when I was pulling taps I'm going to redo some sections of my woods with long laterals, a few too many taps, and backwards sloping laterals. It still worked well, but I think it can work better if I take some time and a little money to run some short mainline runs. It will also allow me to get some trees I didn't get this year and get me up to around 450 taps in this orchard.

[Parker]

Vacuum will pull sap from the other side of the tree,,,studies have been done where dye was put in the trunk of the tree on one side and the vacuum pulled it out of the other side,,,,,
Amber- if this was your first year with NEW tubing /set up your sap yeild will drop yearly if all other factors remain the same...an orchard runs the best the first year, fresh plastic (in my limited experiance)
There is a trmendous diffrance in sap yeild between 16"-18" and 22",,,,,there is also real big diffrance in yeild between having 18" at the releaser and 18" at the last tap............I cant comment on 25+" caus I have never pulled that hard for any lenght of time
I know a few people that consistantly make over 1/2 a gal per tap,,they all have 1 tap per tree,,one fellow has 20,000 tap and made 11,000 gals. this year,,,,,when I walk around in his woods I cant believe he only has 1 tap in a 28" tree,,,,but it works for him......
If you have 100 trees with 100 taps your average per tap will be higher than if you have 100 trees with 250 taps (how I started out)

[KenWP]

I had big trees on buckets with 3 taps running into one bucket and I had big trees with one tap that actually gave more sap then all three did. After seeing how little difference the extra taps did I will probabbly put out more buckets on one tap alone next year instead.

[Smith's Maple]

I put more than one tap per tree, on vaccum, for the last two years. I pulled a 21.8 gals per tap last year with 22 inches of vaccum. This year I pulled a littte over 24gals per tap with 25" + vaccum. Made slightly over 1/2 gallon syrup per tap. We also have 7 sap ladders in my system.

[Snow Hill Farm]

Some more interesting information... I have a friend 5 miles away with a very similar set up to mine, 800 taps on vacuum w/ dry lines, similar vacuum systems, same elevation. He is semi-retired and has had the time to go through the bush and add a ton of black 3/4" and also reduce the taps per lateral to 4 or less. We compared notes and he has approx. 10,000 ft of main while I only have 5,000 and I also have a lot of laterals that are too long with too many taps (which I knew but haven't had time to do the right way yet). I made 272 gallons off 800 taps and he made 450!!!! I'm not kidding. His vacuum level was 23-25 all season while mine was 20-22. This definitely shows that vacuum levels, lateral length & number of taps makes a huge difference.... I'll be adding a lot of main and shortening a lot of laterals before next season (and fixing more leaks during the season)!

[maplecrest]

my new woods this year, had 4 taps per lat. and wet dry system. i put two taps only on large trees. higher vac helps but fixing leaks is the place to start. last year i made .5 on vac levels of 19 inches, but got out there and found and fixed the leaks this year i run higher vac levels 23-26 and made .1 percent more.

[PATheron]

Jeff- How much are you spacing your mains to get your four taps per lat? I kind of go on lat length and try to keep them 5 to 10. I go by normal tapping guidelines for two tappers though Id say. I only have a few I put three in. Usually stop at two. Im going to do a bunch of finetuning this year becouse Im not putting a new big bush in. Just want to make everything perfect at home. I am going to put the little dairy pump bush in for fun though. Just want to see things PERRRRRFECT. Theee(waitin for the big run)rooon

[markcasper]

Theron, You've got to be kidding!!.....isn't even May and your back to waiting for the big run.

[maplecrest]

after where i was this weekend i am ready for the big run to see the operations i looked at makes your mind spin. i tryed to space my main lines as close as possible. some of the lats did get lond on the ends or where it fanned so to speak. i put an extra line where i would have had two before.lets put it this way i used 60 rolls of tubing for 1600 taps. so rule of thumb was 25 taps to the roll. that would be 1500 so i got an exta 100 out of it.

[sapman]

So far I've used 50 rolls for just over 1000 taps. Of course, this includes the droplines. It's amazing how quick a 500' roll disappears stringing laterals!

Tim

[220 maple]

Smiths Maple
How did the article turn out in the local newspaper? I visited your camp on a saturday in early March and you had a writer there doing a interview. Is the article on line somewhere? I hope I was of some help by asking you questions that I knew she would not have any knowledge about. Also I have a friend who needs to put in sap ladders next year, he wants to come see yours are they still in place or do you take them apart in the off season? You can PM me thru this message board.

Mark 220 Maple

[Smith's Maple]

The 21 foot sap ladder is down for the year. The rest of them are still up.

[caseyssugarshack93]

parker, take a look at this research paper that the Gov has a link posted too on the maplechatter,It will tell about sap movement in the tree with Dye.
http://www.fs.fed.us/ne/newtown_square/publications/research_papers/pdfs/scanned/rp107.pdf

[HazensNotchSugarShack]

Vacuum will pull sap from the other side of the tree,,,studies have been done where dye was put in the trunk of the tree on one side and the vacuum pulled it out of the other side,,,,,

I know a few people that consistantly make over 1/2 a gal per tap,,they all have 1 tap per tree,,one fellow has 20,000 tap and made 11,000 gals. this year,,,,,when I walk around in his woods I cant believe he only has 1 tap in a 28" tree,,,,but it works for him......
If you have 100 trees with 100 taps your average per tap will be higher than if you have 100 trees with 250 taps (how I started out)
Parker Am I understanding you correctly. If you have all trees 18 inch diameter you put one tap with vac and yield 1/2 gal syrup per year. But if you don't use vac and put two taps per tree the yield would be only 1/4 gal per tap per year. But still 1/2 gal per tree per year without the cost of vac. Double the taps seems cheeper and less agrivation than vac. What am i missing here!

[maplecrest]

to me it is not worth even doing if you cannot get at least 1/3 of a gallon per tap. a quart per tap is alot of work with little pay back. you would pay for your vac system in the first run. you would pay for the spout adapters in the last two drums of extra syrup you made.to get to 1/2 gallon per tap. or look at it this way. with vac tap 1/2 as many trees. it is not hard to maintain 1/2 gallon per tap once you get there. you will be looking to get more out of every tap you have.

[HazensNotchSugarShack]

I thought I was doing good getting a Quart of syrup per tap per year on gravity.

[HazensNotchSugarShack]

Maplecrest. What are the spout adapters you are talking about? Are they the check valves I hear people talk about?