UV LIGHT

[the old guy]

CAN SOMONE EXPLAIN TO ME HOW A UV LIGHT WORKS? I KNOW THAT IT KILLS MOST OF THE MICROBIAL BACTERIA IN THE SAP BUT BUT WHAT DO YOU DO? RUN FROM YOUR GATHERING TANK TO THE UV, THEN TO THE STORAGE TANK? HOW LONG DOES IT STAY IN THE UV? I AM NEW TO THIS IDEA AND MAY NEED A LITTLE GUIDANCE HERE. WE ARE PLANNING TO PURCHASE A 2 X 6 OR A 3 X 8 EVAPORATOR FOR NEXT YEAR AND WANT TO DO THINGS CORRECTLY.

THE OLD GUYS
120 TAPS

[Fred Henderson]

That is exactly what you do. The sap just flows thru at the rate of about 10 gals per minute, some will do more. The tank that you put it in to has to be clean. Maybe Brandon will jump in here on this he has one.

[maple flats]

Mine is a small UV. It is rated at 8 gpm but I run it at 5gpm thinking it might be better kill. I run from my transport tank thru the light and into the main storage tank. If I need to unload faster I go to a seperate temp tank and then as soon as I can i pump from this thru light to main tank. Between each day's load the main tank gets cleaned. I also have the ability to pump from the main tank to another to retreat if storage becomes extended such as 3-4 days. The main thing is to run sap thru UV as soon as you can and into a clean tank. Best also if each day's sap is kept seperate and not mixed with other days sap but that requires more tanks unless you can process fast enough to keep up when the sap flow is real good. Other units can run much faster but they run a lot more money, mine is a $300 plus shipping.

[mcmp]

In considering UV treatment in my operation, I contacted Vermont
Proctor Maple Research Center and also Cornell University, Uihlein Sugar Maple Research Laboratroy at Lake Placid, NY.

The following is from my notes during these phone calls;

UV irratiation, damages the DNA of the microorganisms which prevents reproduction and also can cause death. Cornell used a level of 8000 uWatts. This level of UV treatment achieved a 100 fold reduction in bacteria and a 10 fold reduction in yeast levels compared to untreated sap.

From primary research, it appears, that UV irradiation can improve micorbiological quality of sap. However, the finished quality of maple syrup will not be improved over the quality of maple syrup made from sap that was immediatelly evaporated.

The best UV irradiation is achieved when pumping sap thru a 5 micrn pre filter. Sap should be pumped from gathering thru the UV treatment and then into a clean tan, properly sanitized. Re-circulating from a tank thru the UV irradiation an back into the same tank will produce little results as the microorganisms are constantly reproducing.

UV can help in storage of sap. But the best bang for your buck is in the sugar bush, improving quality of tubing and the residence time sap is in lines/tanks before boiling.

UV treatment in no way damages the sap for Maple Syrup. UV hanging over a tank is of little to no use. UV does not penetrate the sap deep enough to be useful

End of notes;

We also discussed air injection, however, they report that the jury is still out on that topic.

Paul

[brookledge]

That is a good explanation. I have a 12gpm unit and also use a 3 foot bulb that hangs over my head tank (tank that supplies the evaporator)
For me cleaning the head tank is not easy so I have had good luck with the UV light hanging over the tank to keep it clean. As Paul said it will not penetrate the sap but it does work well in keeping the tank walls clean. They don't get slimmy like they would if the uv wasn't there.
Keith

[WESTVIRGINIAMAPLER]

I have a Wedeco just like the one in the Leader catalog. It is the 13 gpm and I have it mounted on the wall next to my 625 gallon stainless milk holding tank. I pump it from the two tanks on my tractor thru the light and into the holding tank. I pump it thru about 10gpm as it is necked down to 3/4" and this is about as fast as it will flow. The stainless tube which houses the UV lamp will probably hold aproximately a quart, so that gives you an idea of how long it stays in contact with the light, not very long. Just be prepared to make a lot of light syrup.

[WESTVIRGINIAMAPLER]

I forgot to add I picked up the UV lamp on the internet two years ago for $ 300 delivered to my door from Aquascience when they were running an internet special. :D One thing to remember about UV lights is that you need a whole house unit to get a good kill with one pass. A lot of what is out there and nearly everything on ebay is a small light made for a fish pond that relies on continual circulation. :?