Pasteurizing Milk, Home Method - Temp & Times

[frhd]

Every where that I read, says "cool milk very rapid" or "rapidly"! but it don't talk about how much rapid? 2min? 10min? 15min?
please say a time for cooling.
After 20 sec in 72C I cooled milk to 4C in 14 minutes. Is milk pasteurize?

[coffee joe]

No, your milk is not pasteurized unless you have a high pressure system. HPST(high Pressure short time) requires commercial equipment. This requires 15 seconds @ 73ºC, 3 ATM and cool to 4ºC in under 1 minute with an ammonia cooling system.

Best home pasteurization recipe is to heat to 66ºC, it should stay there for  30 min. Cool as fast as possible to 4ºC this could take 20 min or so.

Pasteurization does not destroy organisms that grow slowly or produce spores. Know your milk source.

[frhd]

Are all users agree with "coffee joe"?

[Oberhasli]

I don't agree.  I have a home pasteurizer - all stainless steel made by Hoegger Goat Supplies.  This machine gets my milk (two gallons) up to 160 degrees F and buzzes when it is done and then I flush cold water through the system.  Coffee Joe, are you saying my pasteurizer doesn't pasteurize my milk?  I don't think this "home pasteurizer" is considered a commercial one.  I used to pasteurize on the stove, but the milk always seemed to get that "boiled milk" taste.  I'm pretty sure that the method frhd used should be safe for pasteurizing.

Bonnie

[coffee joe]

Bonnie,
I am probably using the same system that you are and have had the pasteurized milk tested several times at a very good university lab, and pasteurization is as good as can be done in a vat system.  It is the 20 second time frame in frhd's original post that is problematic.
My little system, purchased from Cheesemaking.com, increases pressure to about 2 ATM and keeps the milk at 155ºF for just about 30 min before buzzing. I then run ice water through the system and get to 40ºF in about 15 min.
 

[Oberhasli]

Yes, I can see where the 20 second time frame wouldn't be long enough.  When you mentioned "commercial" systems - I envisioned those big vats that professional dairies use.  I don't consider the home pasteurizer we use as a "commercial" system - just a more affordable one.

Bonnie

[coffee joe]

Bonnie, just for your information. Actually, commercial system are not vat, also known as batch, systems. Today most commercial pasteurization is done with inline continuous systems. These raise the pressure and the "hot" part of the plates are just long enough to keep the milk at 73ºC for 15 seconds. The milk then goes into a "cold side" which is cooled by an ammonia system bringing the milk down to 4ºC within seconds.
We do it the old way which works just fine!