Ecoli infection.

[Rik vonTrense]

Or a blown cheese.

This is a FAQ as it is very easy to get an infection of ecoli especially with milk that has been left out of refrigeration for any length of time like over night in the summer.

Maybe you got the milk out of the fridge to do a make and left it for a few hours to get up to room temperature, this is when you can start to get an infection.

Ecoli is present in most milk and even pasturisation doesn't always kill it
it is always present in the animals gut and gets onto their teats via a calf'a mouth etc.

The easiest way to recognise an infected curd is that the curds will not sink and tend to float on top of the whey even when cooked to make them shrink in a cheddar type cheese.

If you inspect a portion of curd you will find very tiny holes in the cheese and if you taste them they have a slightly bitter after taste and not sweet like curds should be.

It is best to dump a cheese where the curds have blown as you will not get a satisfactory cheese from them as frequently the cheese swells up and may split and run with entrapped whey.

This type of ecoli is not toxic but just incoinvenient to the artisan cheesemaker.

Milk is like meat for sausages it must be kept cool except when you are cooking the curds or bringing it up to the curd cooking temperature.


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[Franco]

Do you have a photo of blown curds?


Franco

[Rik vonTrense]

Franco

Blown curds are larger than normal after you have cut them but if you pick them up they are very soft and they are covered in small pinholes.

on top of that the curd floats if left in the whey. really right up out of the whey as if it were being pushed up.

I will have a look to see if I can find a photo though.

Do you think you have some then??

Taste them they will not harm you but they will have a bitter after taste.

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[Carolyn Tillie]

Here is something that confuses me...

One of the comparisons made here in the states between Californian cheese and Wisconsin cheese (two big cheesemaking states) is that apparently in Wisconsin they can keep their milk out for several days before starting the cheesemaking -- laws that preclude Californians from doing that.

I am going to research this further with the professional cheesemaker who told me this information, but am wondering how toxic it could be. After hearing that, I made three different cheddars from milk that I deliberately let sit out for a day and am now worried I might kill people!

[jenny_haddow]

Hi Carolyn,

Presumably the milk is covered as it sits to keep out unwanted visitors, in which case I don't think you need to worry.
I notice that you can get raw milk in California, not all states allow its sale, if you can get hold of that you can really make some cheese to die for.

Cheers

Jen

Re: Oddleys post below, the section on milk handling is of interest too.

[Oddley]

Carolyn if you look HERE and then at buttermilk you will see that when milk is left out that it is likely that lactic acid producing bacteria will be predominant in the milk. The same can be achieved by the addition of yogurt or a buttermilk starter. This is probably the reason that Wisconsin milk is left out, to produce a wild starter culture.

[Carolyn Tillie]

Thanks for your help -- it was an interesting debate between using the freshest milk possible and the idea of actually aging it or leaving it at room temperature (covered, of course).

I am endeavoring to utilize only the freshest milk, but admittedly get lazy bewteen the time of the milk acquisition and the production (sometimes a day or two or three!)

[georgebaker]

Hi
I think Lancashire was traditionally made with both milkings of the day combined, this must have meant that one lot must have been left 12 hours
George

[jenny_haddow]

Note Pokerpete's observations regarding Lancashire cheese in the Hard Cheese section under Franco's Lancashire Cheese. Very interesting, and no doubt an age old process, which would almost certainly have crossed the pond with the early settlers.

Jen

Sorry you'll have to trawl through and find it, I haven't a clue how to post the exact spot!

[saucisson]

This I think:

[quote="pokerpete
For what it's worth Lancashire 'Crumbly' cheese was made, in the days before refrigeration, by keeping the the curds from the first day, and then the second. The third days curds were mixed with the previous two days curds, thus resulting in the difference with other cheeses.
Any comments?[/quote]

Dave

[markh]

Quite often the cheese recipes call for a'ripening' period of about an hour at 30C after inocculating the milk. I would assume if you are relying on natural moulds & bacteria it would take longer at lower temperature or concentration