Overcooking - Cut Rennet Coagulated Curd

[PollyG]

Hi everyone!
I just found this forum, while looking for a possible save for a cheese I just messed up on.
(first an intro, to be polite: I've been making cheese for about 3 years, mostly cow milk based, almost all using Ricki Carroll's book and materials.  I've got a pretty good knowledge of microbiology, and would really like to know more of the science behind cheesemaking, for which my knowledge is still kind of at the "this is magic" level for me).

Okay, here's my problem: today I was making a Jack cheese, and let the temperature get up to about 140, for between 5 and 10 minutes, before I noticed it, at which point I quickly added cool water until the temp was back at 100.  Is there any hope for the cheese?

The temperature spike happened after I had stirred the curds at 100° for 30 min, then poured off half the whey, and was holding the temp at 100° for an additional 30 min.  The temp had dropped a couple of degrees, so I turned on the burner.... and then immediately forgot that I had done it.

So - have any of you done this particular mistake?  Is there any way of saving it? I figure the starter microbes are pretty dead, and that even if some managed to survive, there probably aren't enough to properly age the cheese.  So will the curds just rot?  And could it be possible to inoculate them with more starter, and fix it?  I'm guessing that it won't be, but thought it was worth asking.  It was 4 gallons of milk!!

Thanks for any input,
Polly

[smilingcalico]

Hi Polly. Bummer about the mistake. While you did kill off much of the starter culture, it is likely that some survived. This probably means that in the end, you will miss your final pH marks as there will be less active culture. You will also likely end up with a cheese that doesn't taste like what you've envisioned. In the end though, I would always say make lots of notes and proceed with finishing  the cheese, as you never know if the accident might be a happy one that you wish to recreate. Plus, if you've made or tasted many jacks before, you'll now be better able to see what high temp does to the flavor (you could likely apply this to other cheeses too).

[Cheese Head]

Hi Polly welcome, there's some info in our Wiki: Starter Cultures Function article which shows that Meso can only live to 102F and Thermo to 132F however I believe that is not a 100% line and there are probably and hopefully for you some stragglers over that line. Given your cheese is probably pressed and salted by now I second smiling's thoughts, I would just let it age, maybe a little longer at warm air-drying stage to allow better multiplication of the microbes. Sorry but I have no good idea on how to add lactic acid prod culture back into your cheese.

Here's a thread on over-heating milk but before adding rennet.

[PollyG]

Thanks, you two.
One thing I'm concerned about is that if I killed all the mesophilic microbes it seems like it would be easy for some different, potentially pathogenic, microorganisms to set up shop in the cheese.  If that happened, would there necessarily be something to clue me in to it, before I ate the cheese?  And does anyone know what the most likely contaminants would be? (I just looked up Clostridium botulinum, and was happy to see that it can't live in cheese).
The pressed cheese tastes like I would expect it to, although the texture is a bit less squeaky and more rubbery than usual (which is what I would have expected).  I will keep on, and see what happens, I guess.  An interesting experiment, at the very least.
Polly

[smilingcalico]

Unfortunately, without lab testing, you'll have no way of knowing what's growing in the cheese. If you started with clean milk though, I wouldn't worry too much. Besides, if you killed the culture with temp, you killed many possible pathogens too.  Just before you eat it, smell it, this won't fully clue you in, but if it turns your stomach,steer clear.