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View Full Version : How to check bacteria count??????



smitty76
02-06-2010, 08:42 AM
Ok guys, and gals,:-|
Looking for some enlightenment here. How is bacteria measured in sap or what ever? Is there some kind of meter or test strips or????????????:confused: :confused:

Any feedback would be great.:D

Smitty76

KenWP
02-06-2010, 10:08 AM
Test you sap for sugar and then test it a while later if it's gone down you got bacteria. You have to figure its got germs since it's out side hanging on a tree and all that good stuff. That's why if you boil it fast you get a better product. The gizmo to test for germs is worth a few dollars and hardley worth your time unless you wanted to test for improvements of different methods in a big operation. Just assume its got them and try to control how many you don't add to it. Even in a sterile operating theatre there is germs just not as many as there could be.

PerryW
02-06-2010, 10:53 AM
sit tight and hopefully the doctor will respond on this thread.

you can certainly smell it in the sap; you can feel the biofilm on the tank surfaces and you can see it in the cloudyness of the sap, but I never heard of a practical way to actually measure it.

Ken I'm guessing if your sugar content is going down, you are fermenting (yeast) and will smell vinegar.

smitty76
02-06-2010, 11:36 AM
Perry, I was hoping for the dr. It does not really matter as we all keep things as clean as possible. I was just wondering if any one out there in Syrup Land, USA(thats right, paridise) and yes Ken, that merges into Canada) had ever heard of such a thing.:mrgreen:

Its cold here and iam not doing much, just hanging with the offspring.:rolleyes:

Homestead Maple
02-06-2010, 02:17 PM
It's a lengthy process to check bacteria in drinking water. The water is drawn through a special media paper under very sanitary conditions and the media paper is incubated for 24 hours at a certain temperature and the colonies of bacteria whether they are coliform or non-coliform are read under a special light. Coliform bacteria being from warm blooded beings and no-coliform from naturally occurring substances. That is what I remember from working in a water treatment plant at one time. When the Dr. sees this he'll have a lot more info on it I'm sure. But to do a bacteria test for sap would almost be to late by the time the test was done and read.

Homestead Maple
02-06-2010, 02:19 PM
It's a lengthy process to check bacteria in drinking water and just as long for sap unless some quicker way has been developed. The water is drawn through a special media paper under very sanitary conditions and the media paper is incubated for 24 hours at a certain temperature and the colonies of bacteria whether they are coliform or non-coliform are read under a special light to determine which is which. Coliform bacteria being from warm blooded beings and non-coliform from naturally occurring substances. That is what I remember from working in a water treatment plant at one time. When the Dr. sees this he'll have a lot more info on it I'm sure. But to do a bacteria test for sap would almost be to late by the time the test was done and read.

DrTimPerkins
02-06-2010, 06:42 PM
How is bacteria measured in sap or what ever? Is there some kind of meter or test strips or??

Basically you have four choices:

1. The first is not terribly cheap, and definitely not very easy, and takes a while. You can plate out the microrganisms on a petri dish containing growth media. If you're not sure of the types of microrganisms, you have to use lots of different types of media. After a while (days to weeks) you'll see the colonies growing, and maybe can identify some if you're an expert in that sort of thing. You can get an idea of the number and type of microrganisms.

2. Another type is a bit faster, but not easy, and not terribly cheap. You need a special filter and a microscope to count the number of microbes on the filter. Leave this one to the experts.

3. The third method is fast and easy, but not cheap. It employs a device called a luminometer and special test probes. You immerse the probe in the sap and suck up a sample (or another type is a swap you can wipe across a surface to see how well you cleaned it). You then twist down the probe and it breaks a small ampule of chemicals in the probe so they mix with the sample. You stick the probe into the luminometer device and push the sample button. If there is ATP (adenosine triphosphate -- a form of chemical energy in living cells), the sample in the probe will glow (one of the chemicals is luciferase, the enzyme that fireflies use to make their flash/glow). The intensity of the glow is proportional to the amount of microbial contamination and the luminometer measures how much light (glow) there is. A sample takes a minute or two, but the cost is quite high (the machine is a few thousand $ and the probes are $5-10 each) and the test probes have a fairly short life-span. Tests have shown that the microbial count measured in sap in this way is directly proportional to the syrup grade. We use this fairly frequently in our work. It gives us an estimate of the amount of microbes, but doesn't tell us what types.

4. The last way is cheap and easy, but not very precise. Check to see if your filters are plugging, run your finger across the tank just below the surface, smell the sap, and see if it's cloudy. Not real scientific, but probably tells you all you need to know.

ennismaple
02-07-2010, 09:54 PM
They mentioned at our OMSPA meeting that you can use a glucometer (used by diabetics to measur blood sugar) to test for glucose levels in the sap. I understand that pure sap straight from the tree is 100% sucrose but heat causes bacteria growth to convert the sucrose to glucose and fructose. Higher glucose levels will mean more bacteria. If this is correct I'll make sure my buddy who has type 1 diabetese gives it a try for me this season!

DrTimPerkins
02-08-2010, 06:28 AM
They mentioned at our OMSPA meeting that you can use a glucometer (used by diabetics to measur blood sugar) to test for glucose levels in the sap. I understand that pure sap straight from the tree is 100% sucrose but heat causes bacteria growth to convert the sucrose to glucose and fructose. Higher glucose levels will mean more bacteria. If this is correct I'll make sure my buddy who has type 1 diabetese gives it a try for me this season!

The glucose meter doesn't directly measure microbial contamination, but can provide a rough indication of the amount of microbes. The device (which is a blood glucose meter) measures glucose.

The vast majority of sugar coming from a maple tree is sucrose (not quite 100%, but pretty close). When microbes feed upon that sugar they split it into 2 smaller sugars, glucose and fructose, also called "invert" sugar. The meter measures the glucose component. The higher the level of invert sugar, the more darkening of the syrup and stronger flavor development you will get. This is primarily because the invert sugars caramelize at a considerably lower temperature than sucrose. See http://www.uvm.edu/~pmrc/sugarprof.pdf for more information if interested.

Beweller
02-08-2010, 04:00 PM
I have in my possession a "Low cost water monitoring kit", LaMotte, which I believe came from Ben Meadows. It includes a test for coliform bacteria which involves culturing for 48 hours. The instructions say nothing about other microbial life.

Perhaps similar tests for other microbial forms are available.