Massachusetts Microvat Pasteurizer

I designed and assembled my own vat pasteurizer that meets the requirements of the federal Pasteurized Milk Ordinance. There isn’t a commercial pasteurizer that is small enough for our herd size and my desire to make farmstead cheese with the last evening’s milk combined with the morning milk. Many people advised me to get more goats or hold milk until I had sufficient quantities for a commercial pasteurizer or advised me that my venture was too small to succeed.  Nonetheless, during my licensing process with the state, I took care to set up a satisfactory review process so that my state public health dairy inspector Alan Metro could evaluate this self-designed micro vat pasteurizer. I did not start purchasing components and arranging stainless steel fabrication of a cover until Alan had approved the concept design.

The vat pasteurizer consists of these components:

1. an electric cooktop with a burner of sufficient wattage for the pasteurizer;

2. a large 33-quart stainless steel stockpot that acts as a water jacket for the pasteurization vessel;

3. a series of 3-gallon, 4-gallon, and 5-gallon stockpots all of the same diameter that function as pasteurization vessels and cheese vats  and that I can select among depending on the amount of milk I have at hand;

4. a stainless steel cover with suitable fittings to hold pasteurization instrumentation;

5. a 2000 ml Erlenmeyer distilling flask in which water is boiled to provide steam via suitable Tygon tubing to a fitting on the vat cover;

6. a variable-speed laboratory stirrer with a stainless steel shaft and propeller;

7. pasteurization instrumentation (2 digital thermometers that are both indicating and recording devices – one for airspace and milk temperature and a 2-pen chart recorder – I chart airspace temperature as well as milk temperature).

The cost, excluding the cooktop, was just under $4,000 with two thirds of the cost in instrumentation.