Author Topic: Coagulation, Rennet - Slow After Changing Cow Breed  (Read 3929 times)

lcarter

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Coagulation, Rennet - Slow After Changing Cow Breed
« on: February 02, 2011, 06:21:37 PM »
Hi, I am relatively new to this and am actually just working with a friend to try to solve some problems.  Recently, we switched our herd of Jersey and one Holstein over to mostly Ayrshires.  Some time after this, we started having problems with our cheese taking way to long to coagulate.  Before the switch, our milk would coagulate in 40/45 min range.  Now it is taking closer to 55 min and one batch last week took up to 1hr and 25 min.  We have tried switching to new starter - no help, new rennit - no help, calcium cloride - no help.  Our overall somatic cell count has not been that high, right now it is around 270,000 to 300,000.  One cheese maker suggested we test each individual quarter on our cows to see if we could narrow down the problem.  I have read in several places that you may need to increase your rennet depending on the type of cows etc. 

Does anyone have any ideas of know of a similar problem and the solution for it?

Thanks in advance,
Lora

Sailor Con Queso

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Re: Coagulation, Rennet - Slow After Changing Cow Breed
« Reply #1 on: February 02, 2011, 07:10:49 PM »
Lora,

Search the forum for flocculation method. This is a really important technique that most books or recipes do not talk about.

Average coag time depends on the cheese. There are some where 2 hours is normal (like a Fourme di Ambert), so it would help to know what you are making. Are you using raw milk? If so, do not use calcium chloride.

Yes, increasing rennet is often necessary for a variety of reasons (like changing cows). The floculation method will give you an idea of how to compensate.

lcarter

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Re: Coagulation, Rennet - Slow After Changing Cow Breed
« Reply #2 on: February 02, 2011, 07:24:07 PM »
Thank you for your advice.  I will search later.  As far as the cheese we are making, we do cheddar, parmesian, swiss, gouda, and feta.  Thank you, Lora

Sailor Con Queso

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Re: Coagulation, Rennet - Slow After Changing Cow Breed
« Reply #3 on: February 03, 2011, 02:24:21 AM »
All of those cheeses use different flocculation multipliers and coagulate properly at different times.

zenith1

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Re: Coagulation, Rennet - Slow After Changing Cow Breed
« Reply #4 on: February 03, 2011, 02:36:04 PM »
Changing the breed used will affect the cheese making process. So will the time of year as the feed make up changes. Not sure what the milk make up(protein,fat) of your new breed is as compared to your old, but that is a good possibility for your problems.

lcarter

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Re: Coagulation, Rennet - Slow After Changing Cow Breed
« Reply #5 on: February 03, 2011, 02:51:00 PM »
Keith,

Thanks for the reply.  I am not sure right off what the difference is in the milk as my brother did that research.  Obviously, people make cheeses from all sorts of different cow breeds, so to me that means you adjust for your new milk.  My question is what is the most likely thing we will have to adjust?  Rennet amount?  Starter amount??


lcarter

  • Guest
Re: Coagulation, Rennet - Slow After Changing Cow Breed
« Reply #6 on: February 03, 2011, 02:56:50 PM »
Sailor Con Queso,

Thank you for your information.  I know understand what the flocculation point is.  My question then would be, say I was making cheddar from late lactation Ayrshire cows in the winter time (i.e. they are inside on haylage or hay).  What happens if my flocculation point isn't until 28 - 30 minutes?  Is there something wrong?  Am I losing quality in my cheese or is it just that the yield goes down?  I see there is a range for the different cheeses which makes a lot of sense to me but is there also a range for rennit amounts and starter amounts? 

thank you, Lora

Sailor Con Queso

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Re: Coagulation, Rennet - Slow After Changing Cow Breed
« Reply #7 on: February 03, 2011, 06:02:11 PM »
Lora, Search on flocculation or spinning bowl. Add your rennet and start a timer. Put a small bowl on top of the milk. Initially, that bowl will easily spin. When the bowl stops spinning, THAT'S the flocculation point. That should generally be 12-15 minutes. If it is a shorter time, you should use less rennet next time. If it is longer, use less. This helps you compensate for changes in milk and/or changes in rennet, etc.

cnorth3

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Re: Coagulation, Rennet - Slow After Changing Cow Breed
« Reply #8 on: February 03, 2011, 09:53:31 PM »
Lora, Search on flocculation or spinning bowl. Add your rennet and start a timer. Put a small bowl on top of the milk. Initially, that bowl will easily spin. When the bowl stops spinning, THAT'S the flocculation point. That should generally be 12-15 minutes. If it is a shorter time, you should use less rennet next time. If it is longer, use less. This helps you compensate for changes in milk and/or changes in rennet, etc.
More?

tananaBrian

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Re: Coagulation, Rennet - Slow After Changing Cow Breed
« Reply #9 on: February 03, 2011, 10:35:21 PM »
Sailor... should Lora measure pH v. time to determine if her new milk is ripening more slowly?  Maybe the pH is as optimal for the rennet?  This is what I would do, assuming I still had the same data from the prior cows.   Am I (a newb) off base on this?

Brian


zenith1

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Re: Coagulation, Rennet - Slow After Changing Cow Breed
« Reply #10 on: February 03, 2011, 11:43:40 PM »
Lora. my guess would be that you need to adjust your rennet amounts. I have attached a couple of charts that have previously been posted by or are attributable to forum members.

lcarter

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Re: Coagulation, Rennet - Slow After Changing Cow Breed
« Reply #11 on: February 03, 2011, 11:51:46 PM »
Keith, Brian, cnorth, 

Thank you all for your comments.  I am hoping to spend time with the cheese person on Monday, so I will be able to better see how she does things.  As far as pH, the cheese lady told me that the pH of the milk is running high when they first heat it.  Is this a problem?  Could this possible cause the problem with long coagulation times.  Thank you, Lora

Alison

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Re: Coagulation, Rennet - Slow After Changing Cow Breed
« Reply #12 on: March 23, 2011, 12:59:35 PM »
Dear lcarter

I'm using store bought aryshire milk and have found that coagulation times are pretty high (>40min and longer). In my case I believe that the milk is stored at low temperature for a long time. That appears to reduce the renneting ability of the milk (Summer et al, Veterinary Research Communications, 30(Suppl. 1) (2006) 387–389). I recently (last batch!) solved the poor coagulation by heating the milk to 40 degrees Celsius for 10min (recommended by Fox, Irish Journal of Agricultural Research, Vol. 8, No. 2, Aug., 1969) before continuing the cheese making process. Specifically I'm making fresh mozzarella, with citric acid to modify the pH. (It seems that CaCl is inadvisable for mozzarella, so I don't have that route).

The down side to what I'm recommending is that it may encourage unwanted cultures, so perhaps a pasteurisation step may be preferable (~65 degrees Celsius for 5 min). I expect that 10min above 40 degrees C is the trick rather than exactly 40.

Ciao
Alison


Sailor Con Queso

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Re: Coagulation, Rennet - Slow After Changing Cow Breed
« Reply #13 on: March 23, 2011, 01:33:58 PM »
Alison - you need to search on flocculation method. This is a technique for properly adjusting your rennet to achieve consistent coagulation times.

Alison

  • Guest
Re: Coagulation, Rennet - Slow After Changing Cow Breed
« Reply #14 on: March 29, 2011, 04:14:13 PM »
Hi Sailor Con Queso

Advice taken, and thanks! It was effective for making a fresh mozzarella with bacterial acidification post coagulation (sorry if I'm using the wrong terms). In that case, when I used the flocculation method I don't need to add citric acid to modify the pH before coagulation. The multiplier of 3.5 worked well and after 99mins (!) a clean break was in evidence, magic! In my setup it’s hard to maintain 32C for 99 minutes (never mind me  ::))

Could I push it a bit further though? In the case of the non-traditional citric acid mozzarella, there is always a bit of curdled milk that floats to the top of the milk after adding the citric acid (diluted with water and drizzled in slowly while stirring). I could probably refine the citric acid levels to avoid this (anybody know where to find a curve of pH vs acid addition in milk to get a feel for the dependence?). That being said, the after adding the rennet curdled milk gets to the flocculation point within 5 minutes of adding the rennet, predicting a clean break at 17mins from start (!). However, below that 5mm curdled layer the rest of the milk needed much longer, something like 99min but I was impatient and cut it at 70 mins, the resulting curd not great, but will spin. So do you think I should use a multiplier of something like 100/5=20? Or should I refine the acid level? Or am I missing an obvious?

It’s amazing how variable the flocculation time can be … in multi-variable test of 2 batches... .

Thanks
Alison