Tuesday, August 20, 2013

Coliform Bacteria

I was feeling pretty good about my test results yesterday, and then I was reminded by another cow-owning friend that ANY coliform in the milk indicates SOME contamination of fecal matter.  I started to feel disappointed in myself, and thinking that somehow I have failed to be as clean as I could/should be in my milking procedures.  I wanted to learn more about coliform bacteria, and I found this information from UC Davis:

Coliform Bacteria

The coliform group of bacteria comprises all aerobic and facultatively anaerobic, gram-negative nonspore forming rods capable of fermenting lactose with the production of acid and gas at 90°F (32°C) within 48 hours. While the general source of these organisms is commonly accepted to be the intestinal tract of warm-blooded animals, it is emphasized that bacteria of both fecal and non-fecal origin are members of this group. Typically, these organisms are classified in the genera Escherichia and Enterobacter (formerly Aerobacter); but, in addition, a few lactose-fermenting species of other genera are included in the group. In proportion to the numbers present, the existence of any of these types in dairy products is suggestive of unsanitary conditions or practices during production, processing or storage. 

Coliform Count

The coliform bacteria count is used as an index of the level if sanitation and/or water quality employed in the handling and processing of milk products. Coliforms have significance in milk and milk products because (1) they are easily killed during pasteurization and because (2) they are generally regarded to originate from the intestinal tract of warm-blooded animals. Hence, the presence of coliform bacteria in pasteurized milk products is suggestive of unsanitary conditions or practices during processing, packaging; maximum standards for number of coliforms have until now been set at a maximum of 10 per milliliter of gram in pasteurized milk and milk products; however, numbers in pasteurized dairy products should be less than 1 ml., as is the case with up to 90% of samples, if packaging procedures are correct. California standard allows no more than 750 coliforms per mL in raw milk. Less than 100 is considered acceptable. 

So, I discussed the possibilities of ways the milk is becoming contaminated with my friend and reviewed my milking procedures on the cow board.  Here's the ongoing discussion:


If you don't want to visit the link, here are my procedures:

1. Brush cow all over, special attention to underbelly and udder.
2. Using hot water with a gurgle-glug of vinegar in it, wash cow's udder. Never double-dip, special attention given to the teat openings. I use a stack of clean white rags (washed in my "brightest whites" cycle with a gurgle-glug of chlorine bleach added to the wash load) and wash until the rag comes back clean.
3. Dry the udder with a clean, dry rag.
4. Milk the cow.
5. Strain the milk into clean glass jars using a stainless steel milk strainer and disposable milk filter.
6. Wash up: rinse in lukewarm water until the water is clear, wash in hot soapy water with a dedicated milk brush (brush is only used on the INSIDE of pails), air dry.

Jars are washed similarly - lukewarm rinse, run through dishwasher (or hand-washed in hot soapy water) with heated dry. If hand-washed, jars are rinsed with 1 T bleach per gallon of water and allowed to air dry.

My friend, and the members of the cow board first told me to look at my water.  That could very well be the source of the problem.  When the water was brought to my attention, I remembered that when I moved to this house almost 2 years ago, I had to shock my well 3 times to get the coliform bacteria at acceptable levels.  I'm also a cloth diapering mama, and have had problems with diapers stinking.  I took care of my diaper problem by adding a small amount of chlorine bleach to my hot cycle, and it has worked.  Now that I have my test results, I have been alerted to a potential problem with my well.  I'm going to take a water sample to the lab for evaluation.  I want that coliform count in my milk (and water) to be ZERO!!!

I was told by my friend that all milk test results are a matter of public record, and that she has requested copies and found some farms with coliform counts of 150!!!  I'm glad it's not that bad!  She reminded me that I did well for my first test, and not to feel bad.  I am glad for the testing, because I really do want to have the safest, highest quality milk possible.  If not for the test, I may not have known there was a problem.  Now I have a starting point for improvement.

1 comment:

  1. I can't get the blog to stop showing up in bold! I've checked, and it's not set to bold, but it is showing up bold. Weird.