Apprentice - low temperature pasteurization

[IllinoisCheeseHead]

I love this board.  I am about to embark is the world of making cheese.  .  I had a real hard time finding raw milk but I was able to find a location about 2 hours from me.  I would like to know the best way to low temperature pasteurization.  Should I do it in closed bottles in a hot water bath?  Is there a thread that shows how to do this step by step?.  I am going to be making a Mozzarella cheese (traditional)

[Kern]

Low temperature pasteurization calls for 140F for 30 minutes.  Generally, it is done in a closed stirred container.  Stirring distributes the heat though out the milk.  The heat source has so be 20 or so degrees hotter than the milk being heated or heating does not occur.  This is why you need stirring.  Without it the boundary layer would get us to 160 or so.

You may be able to buy whole "cream top" milk locally that has been vat pasteurized.  This will save lots of driving in addition to the mess of trying to pasteurize at home.   

[IllinoisCheeseHead]

Thank you.  And in your opinion, does the flavor of the cheese get impacted?.  I want to be safe but still get the great benefits from real milk

[John@PC]

I'm going to ditto Kern's suggestion about whole cream top/line milk (low temperature pasturized, non-homoginized) milk.  I've used both and now use the LTP/NH exclusively because I can get it for about half of raw milk where I am.  I have had great curd firmness with LTP milk with no CaCl addition and you don't have to worry about doing self-pasturization. 

[qdog1955]

  John----a curiosity question----around here the only cream line milk is the same price as the raw----if that was your joice ----would you use the cream line or the raw?
Qdog 

[IllinoisCheeseHead]

It is supposed to be raw milk.  I am picking it up tomorrow.  From Jersey cows and it will be milk that is collected the same day.  The farm makes cheese of any left over milk they don't sell on a daily bases.  It is 5 dollars per gallon and they do sell both cheese made from LT pasteurized milk as well as cheese made from raw milk (aged 60 days).  One interesting fact is that cheese from raw milk is a dollar cheaper per portion that cheese made from LT pasteurization.

If I low temp the milk, do I need to add calcium?.  Thanks

[awakephd]

Welcome to the forum!

If you have LTP milk, you do not need to add CaCl. It will still act much as raw milk does as far as the cheesemaking process -- which is to say, it will work extremely well. I can't speak to any differences in flavor; no doubt some can detect the difference, but I am not sure that I could. $5/gallon is a great price!

Some things to keep in mind: milk from Jerseys is relatively high in fat; you may need to celebrate that (if you are making double-Bries or cheddar) or adjust for that (if you are making hard Italian style cheese).

If you LTP yourself, you can simply heat it on the stove at medium heat, stirring constantly as it reaches 140° and as you hold it there for 30 minutes. Be sure to allow for some delay in the temperature rise -- turn down the heat when it gets to, say 135°, because it may still rise up from there. This will partly depend on the type of stove you are using.

Once it has finished, set the pan in a sink of cool water to cool it down rapidly. If you are ready to make cheese immediately, take it out when it cools down to your inoculation temperature; otherwise, cool it down enough to put into the fridge.

[Kern]

Thank you.  And in your opinion, does the flavor of the cheese get impacted?.  I want to be safe but still get the great benefits from real milk

Max McCalman argues in Mastering Cheese that he can tell the difference between cheese made with raw milk and the same cheese made with LTP milk everything else being equal.  Maybe he can but the highlighted phrase allows for a lot of wiggle room.  I suggest that any difference between the two would be swamped by the fact that rarely is everything else equal.     I personally use raw milk for aged cheeses and LTP milk for everything else but it is only because the price of each is the same and I can get either from the same source.  I would not drive a couple of hours just to get raw milk if I could get LTP milk 15 minutes away.

[Sailor Con Queso]

One of the top cheeses in the world (probably #1) is the aged Lankaaster from Glengarry Cheese in Ontario. This cheese took the Global Supreme Champion Award (Best of Show) at the Global Cheese Making Competition in Somerset, UK in 2013. Link below.

Global Cheese Award

And the fascinating part is that all of her cheeses are made from fully pasteurized, non-homogenized milk. Margaret says that full pasteurization is actually less damaging to the milk than low-temperature, because low temp is for a much longer time. She pasteurizes, quickly cools the milk to vat temp, and immediately transfers to the vat and starts making cheese. The catch is that some commercial milks are pasteurized for longer or not cooled down quickly, so damage can occur after the required pasteurization.

So anyone that tells you that you have to use raw or low-temp milk to make great cheeses is wrong.

[Kern]

The problem for the amateur cheese maker is getting information on exactly how the milk was pasteurized.  McCalman states that pasteurized milks taste "cooked".  Even he does not distinguish between cheeses made via the different routes of pasteurization.  I think you can make a great case that milk is less damaged by 1 second at 161F that it is by 30 minutes at 140F.  But, it is likely more damaged at 161F for ten minutes than at 140F for 30 minutes.  The "rules" as stated by the FDA/USDA can be read as minimums.  So, no inspector is going to look twice at 161F for ten minutes since it far exceeds the minimum.  I'm not privy to exactly what goes on inside a milk plant but know if a process meets the regulation minimums and it is to the advantage of the producer to exceed them then they will be exceeded.  For example, just as it takes energy to heat milk to 161F it also takes energy to chill it and the faster one chills the 161F milk the more power (cost) it takes.  Thus, a milk producer might well run milk through the pasteurizer into a holding tank then into the homogenizer, into an air cooled heat exchanger and then into the chiller.

In our area the only non-homogenized milk available is vat pasteurized (140/30).  So, the option of getting quick chilled (161/1 ) milk is not available.