Thursday, November 14, 2013

Milk Cooling- It’s So Important!

I have been asked why I cool my milk in an ice water bath inside my fridge.  Well, simply, it's the fastest way to get milk cooled that I have available to me, and having the ice water bath inside the fridge makes it so I don't have to remember to transfer the milk to the fridge after it is cooled.  It takes up a fair amount of space in the milk fridge, but having quickly cooled milk is essential to the best quality raw milk.  The speed at which milk is cooled can have a great effect on how long it lasts and how good it tastes.  I want the milk from my cow to last at least a week, if not longer, and to taste excellent.  When I first started home dairying, I had goats and cows, and came across this excellent resource in one of my goat milk cheesemaking books.  It has since been published online, and so I decided to share the link here.  

Milk Cooling- It’s So Important!

And here it is, cut and paste:

Are you getting good grades when it comes to cooling your home milk supply? One of the most important factors in great quality milk is how quickly the milk is cooled.

Milk is perfect medium for bacteria (that’s why it works so well for cheesemaking).  Unless you are doing a good job of cooling the milk to slow down the development of harmful bacteria, they can be multiplying by the millions. This is even more important if you are using your milk raw. Pasteurizing the milk kills E Coli as well as many other harmful bacteria.

How close to Grade A are your milk cooling practices?  Many of you have various ways of handling your milk and think you are doing a good job.  Have you taken the temperature of your milk to be sure that it is getting cooled quickly?

If you are at least a Grade B give yourself a pat on the back.  This rating is very good for home use.  Most of us cannot meet Grade A standards without the use of commercial coolers.

I did some milk cooling testing to find out just how quickly each method cooled the milk.  Below are the results.

Grade A:

The milk is placed in bulk cooling tanks, which are refrigerated, and the milk is quickly cooled while being stirred.  This method assures the milk will be at 40 degrees in less than 30 minutes.  Usually it is at the temperature instantly then held to just above freezing.

Grade B:

Milk is placed into containers small enough to place into tubs or a sink of ice water.  This is acceptable for home use.  This method cooled the milk to 48 degrees in 30 minutes, 42 degrees in 60 minutes and 40 degrees in 90 minutes.  Results would be considerably better if some form of stirring the milk could be used to speed up the cooling.  Using a home pasteurizer would do an excellent job too.

Grade C:

Milk is placed in a small container and placed in a sink of very cold water with the water being changed 2-3 times during the cooling process.  Water temperature from our well here in Michigan comes out at 50 degrees.  If you live in an area where the water comes from the faucet even warmer, this would not be a great method to use.  The milk would only get as cool as the water.

Grade D:

Milk is placed in the freezer.  I tested a one-quart jar and it took 30 minutes to reach 66 degrees.  In 60 minutes it was at 50, in 90 minutes it was 43 degrees and finally after 105 minutes it was at 40 degrees.  If using a container bigger than 1 quart the results would be even worse.

Grade E:

Milk placed in 1 quart jars and put into the refrigerator.  In 30 minutes the milk was at 76 degrees.  In 60 minutes it was at 67 degrees, after 90 minutes it was 59 degrees.  3 hours later it was at 51 degrees and finally after 8 hours the milk had reached 40 degrees.  This is way too long.  By now the bacteria count has become very high.  Results would be even worse if using containers bigger than 1 quart.  Many home dairies use this method, but this is the absolute worst way to cool the milk.

By Mary Jane Toth, author of A Cheesemaker's Journey and Goats Produce, Too!

Tuesday, November 12, 2013

November Milk Quality Test Results

All tests passed again this month, though I am not satisfied with the coliform count being anything but zero.  It has been very muddy and messy around here with all the rain.  Obviously, there was some contamination, even if it was a small amount.  I am constantly striving to do better with my milk handling.

Standard Plate Count <2500/mL
Coliform 6/mL
Somatic Cell Count 100,000/mL

To pass the state tests, the SPC needs to be <15,000/mL, coliform <25/mL, and SCC <500,000/mL.  My personal goal is to have the SPC at <2500/mL, Coliform at <1/mL, and SCC at <200,000/mL.  I am glad to see the SPC and SCC looking so good, but as I said, I am not satisfied with anything but <1/mL for my coliform count.

Additionally, the thermometer for the state read that the milk was at 32*F when it was initially tested, but my fridge said it was 34*F.  When it reached the state lab, it was at 0.3*C, which translates to 32.54*F.  After 30 minutes at the lab, it was 0.2*F, which is 32.36*F.  I set my fridge a tiny bit warmer.  We don't want frozen milk; very cold will do. 

Sunday, November 3, 2013

So Many Lovely Walnuts

I love English walnuts, and I'm very blessed to have a walnut tree.  They are coming off the tree by the bucketfuls right now.

Last year we gave away too many walnuts as gifts, and I had to buy walnuts before our tree began dropping them this fall.  So this year, I'm hoarding them.  ;)

Friday, November 1, 2013

Moving Day for Chicks

Well, today was moving day for the 1 month old chicks.  They are fully feathered out, and have been going without their heat lamp for about a week now.  Their dust was becoming unbearable in the little house where we have been keeping them.  So, the kids and I moved the chicks outdoors and set them up under the hay shelter.  We used leaves for their bedding.  I like free stuff, and leaves are free!  We'll turn their heat lamp on the first few nights to help them adjust to the cooler temperatures.

Step one was moving them outside.  Step two is cleaning up the thick layer of dust, dirt, and shavings they created while they were indoors.  The kids helped me with step one, but somehow they disappeared when it was time to do step two.  And then I looked at my watch, and it was time to take the kids to swim team practice.  So step two will happen another day.