# Listeria, pregnancy, and yogurt question



## mousebandit (Feb 14, 2007)

Morning everyone! I'm getting ready to make some yogurt, and wondering if I need to pasteurize the milk first? I'm pregnant, and have some concerns about Listeria during pregnancy. (Normally I'm all for raw milk only.) 

I *think* I read somewhere that fermentation prevents listeria, but I don't remember where, can't seem to find it, and to be honest, that doesn't sound logical to me. I hate pasteurizing, but I really don't want to take the chance of listeria during pregnancy (pregnant women contract listeria at 20x the rate of non-pregnant folks, and it can cause fetal death).

So, any info or facts or links you all have on this would ease my mind greatly! 

Thanks so much! 

Tracey


----------



## susanne (Nov 4, 2004)

here is something for you to read
http://vm.cfsan.fda.gov/~mow/FSISLIST.html
this bacterium is found everywhere, and if not clean handled will be in pasteurized milk to. there was a nice discussion about it on one of the yahoo groups. i will search if i can find it.


----------



## mousebandit (Feb 14, 2007)

Nevermind - I've dug up more info and answered my own question! Unfortunately, it looks like I do need to "pasteurize" the milk, to prevent other bacteria from competing with the yogurt bacterias. Apparently it's done as part of the yogurt-making process, heating the milk up to 180-185, then cooling it down to 100 when you add the starter. SO - no need to start with pasteurized milk, but I guess it will get pasteurized in the process. At least it puts my mind at ease, LOL! 

I'd still love anyone else's input though, and any goat-milk specific yogurt tips or facts! THANKS!

Tracey


----------



## susanne (Nov 4, 2004)

i never heat the milk up this far. 165 is hot enough.
i have made yogurt with raw milk with is excellent. of course the milk needs to come from healthy animals and god sanitation with milking.


----------



## mousebandit (Feb 14, 2007)

Susanne - when you make yogurt with the raw milk, do you heat it up to 185 or 165 before cooling it down and adding the starter, or do you just go straight from raw to 110 then add the starter then incubate? THANKS!

Tracey


----------



## HazyDay (Feb 20, 2007)

When I make it, I heat it to 110* then add my starter (plain store crap! ) Then let it "cook" over night. Mine is a little more less sweet, but with some jam or fruit I like it!


----------



## susanne (Nov 4, 2004)

i go to 125 to 130 and add the starter. although goats milk, my yogurt is thik and creamy without adding gelatine or dry milk powder. 
i buy the starter from lehman. i incubate in the styrofoam box that comes with the vaccines from jeffers. i can fit in 4 quart jars.


----------



## DQ (Aug 4, 2006)

I think scalding the milk (180-185*) alters it somehow to help it coagulate better when making yogurt. helps the proteins stick together or something like that. can't remember the exact reason. but its not that milk to be made into yogurt needs to be pasteurized neccessarily although it does help to make sure you are starting with the bacteria you want.


----------



## susanne (Nov 4, 2004)

tracey the discussion about listeria was on [email protected]
you need to be a member to be part of it. it is a very nice group there, talking about cheese making and other things


----------



## goatsareus (Jun 23, 2007)

long time yogurt maker here  and also have done a lot of reading on making things with goats milk. My take is that the milk needs to be heated to 180*F. It can not be a coincidence that so many references specifically state gently heating the milk to 180*F as the first step in yogurt making. Using raw milk is risky for producing a yogurt with the desired bacteria. I make mine in a non-electric insulated thingy and incubate about twice as long as recommended; 10 to 12 hours. I can produce a lovely, thick yogurt this way. I use both dry power cultures from dairy supply places and/or store bought yogurt. I make 1/2 gallon at a time. Good luck, this is a wonderful food :1pig:


----------



## susanne (Nov 4, 2004)

the cheesemaking manual from margaret p. morris says heat the milk to 162 F.
i have made the yogurt from raw milk before and it was delicious.
i would not recommend it to everybody as this needs really clean bedding for the goats and sanitary milking practice.


----------



## goatsareus (Jun 23, 2007)

the organisms/bacteria that can foul a batch of yogurt made from raw milk, are also air borne. There is no way to keep these air borne organisms out of your milk. Pasteurizing is the only way to kill them off.


----------



## susanne (Nov 4, 2004)

how do you prevent this airborne bacteria from contaminating the pasteurized milk? do you have a sterile tent at home?  
this is exactly the point why raw milk is so much healthier then pasteurized. raw milk contains good bacteria that help to keep bad bacteria under control. cook the milk and you kill all te good bacteria as well. 
i think everybody should do a little bit research and then decide what is best.
what is best for me, doesn't mean it is best for you.


----------



## goatsareus (Jun 23, 2007)

susanne said:


> how do you prevent this airborne bacteria from contaminating the pasteurized milk? do you have a sterile tent at home?
> this is exactly the point why raw milk is so much healthier then pasteurized. raw milk contains good bacteria that help to keep bad bacteria under control. cook the milk and you kill all te good bacteria as well.
> i think everybody should do a little bit research and then decide what is best.
> what is best for me, doesn't mean it is best for you.


Excellent question, thanks for asking. But I let you take your own excellent advice of doing research so you can answer that question to your own satisfaction.


----------



## DQ (Aug 4, 2006)

Because not everyone will do the research I'll stab at it to send people in the right direction, and in the interest of being fully informed. Milk is pasteurized and then sanitarily (hopefully) packaged. With the same idea in home canning. you can then in theory store it in your fridge for a period of time before you use it with the knowledge that it is unlikely to be growing anything undesirable. Unpasteurized milk on the other hand is more likely to be growing something because it was packaged and stored along with all the bacteria that made its way into it in various ways on the way to the fridge (and no matter how "clean" the enviroment is there is still stuff floating around and making its way into everything) . which is both why it is argued to be better OR potentially worse for your health. grows good bacteria? yippee, health food. grows bad bacteria? ick. and hopefully not hospital.
Refridgeration of course slows the growth of bacteria in both pasteurized and unpasteurized milk but does not stop it completely. If you want your milk to last "forever" you must can it. of course at much greater temperature. I guess you could call canning it super dooper pasteurization. 
I feel that small children, pregnant women, elderly, immune compromised etc....(blah blah blah ...fine print here) should probably be drinking pasterized milk if it is to be stored for any length of time and not to be used virtually fresh from the teat. That being said I don't think it is the government job to make that decision. 
why can't we have labels the same way we would on raw everything. immune compromised blah blah should not consume uncooked ___________ due to the risk of food borne illness.


----------

