Author Topic: Unintentional Mozzarella - Milk Causes  (Read 2337 times)

BigCheese

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Unintentional Mozzarella - Milk Causes
« on: June 05, 2012, 09:19:22 PM »
Mozzarella has generally been hard for me to make really well, ironically, these last two batches are some of my best, the only problem being that I set out to make Asiago Pressato! Help!

2 times in a row I have begun 11 gallon batches of Asiago Pressato only to realize at hooping that my curds were actually starting to melt. I am using a tried and true recipe I have done in the past. The only difference is I am now using double strength liquid vegetarian rennet whereas I previously used tablet rennet.  I also over-renneted on both occasions and ended up with a flocculation tim of ~5 minutes. I only have 2 possible ideas what could be happening, I don't know how possible they even are:

1) too much rennet
2) we recently had a sick cow but she has been better for some time, but perhaps the PH from her milk is low (?) and therefore after ripening the PH is dropping very quickly. "This evening I will dig out and clean my extech110 and test the PH of her milk.

Any advice from anyone?

The first batch, for 11 gallons of milk, I used 3/16t TA61 and 3/32t LH100.


linuxboy

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Re: Unintentional Mozzarella - Milk Causes
« Reply #1 on: June 05, 2012, 09:42:27 PM »
rennet has little to do with acidity curve. Something about your acid curve or milk is causing the casein breakdown.. that could be a protease in the milk, or something increasing acidity.

if you heat to lower temp, even with milk and acid issues, should not melt quite so much. Not the permanent fix, but a reasonable workaround.

FRANCOIS

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Re: Unintentional Mozzarella - Milk Causes
« Reply #2 on: June 05, 2012, 11:23:00 PM »
Excessive rennt can lead to a soft set and poor curd integrity.  It is usually accompanied by massive fat loss to your whey as well.

BigCheese

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Re: Unintentional Mozzarella - Milk Causes
« Reply #3 on: June 12, 2012, 10:31:11 PM »
Sorry for the slow response. The milk is definitely below the proper PH. Around 6.5 before I began my last cheesemake. I did a Jack cheese so as not to need as high heat, but my PH at pressing was around 5.2, lower than desired. Overall the wheel looks pretty good though.

Right now I am perplexed. I had become worried about mastitis and did a test which resulted negative, but now I read from Margaret Morris that mastitis and high SCC in general increase, not decrease, PH. So I have no clue what could be decreasing the PH of our milk. Nonetheless, the milk has been delicious and lasting long, but I do need to figure this out. Any other ideas?

Pav, what exactly is protease in the milk?

linuxboy

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Re: Unintentional Mozzarella - Milk Causes
« Reply #4 on: June 12, 2012, 10:46:54 PM »
Margaret is correct, pH goes up in high SCC milk. Also usually has higher conductivity.

Is this very fresh? Meaning not stored for long? How old, hoe stored before make?

Milk has natural enzymes that facilitate protein and fat breakdown. When that sits around without pasteurization, it will start acting on the proteins. It's actually good for the first 12-16 hrs after milking because it should give you a higher yield due to higher casein hydration. However, after that, proteases that break down protein go too far, and do the job that lactic acid would do naturally from bacteria. And so you get this pre-broken down type casein that is prone to degradation and will stretch readily.  Usually, higher protease is present in extended lactation milks. With your longer lactations, it's really hard to say without tests if that's true. There's almost no published research on extended lactation.

Might be the season, or feed, or hormones, or bad meter reading that's affecting pH.

BigCheese

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Re: Unintentional Mozzarella - Milk Causes
« Reply #5 on: June 13, 2012, 04:30:01 AM »
Well, I have been using slightly older milk than previous cheesemakes. A few days old. And both times I left milk out overnight so it would require less heating the next day. The reason I assumed this did not cause my issue is because I used to do this and still registered a roughly normal PH in the morning. But perhaps the leaving out combined with other factors is causing my isssue, in which case the solution would be simple enough.

Milk that I intend to use for cheese I filter into 5 gallon SS cans and put in a chest freezer that functions as a fridge. I know this does not chill nearly as fast as would be ideal, but I have no way to chill those large cans quickly and do not want to fill smaller bottles only to combine them later. Anyway, I am going to test the idea that the issue is having left out the milk.

What tests would shed light on the proteases? Do you know if it is something they do California Animal and Food Health and Safety labs based at UC Davis?

linuxboy

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Re: Unintentional Mozzarella - Milk Causes
« Reply #6 on: June 13, 2012, 05:15:21 AM »
I don't believe CAFHAS does it, no. I would start by checking for plasmin. It sounds like protease issue to me... possibly fat lipolysis, which you can guess at through TA, or measure specifically.

You can run a plasmin assay or get one done... but then you'd need a baseline for comparison. Would need fresh milk and older milk from multiple seasons to tell if either native or psychrotrophic plasmin is causing issues.