Author Topic: Has my rennet gone bad already?  (Read 528 times)

Offline SteveScott

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Has my rennet gone bad already?
« on: April 18, 2017, 10:29:58 PM »
I got some animal rennet.  I used a quarter tsp per gallon of milk as indicated and the first time it worked wonderfully.  The second time I used it (maybe two months later) the same amount barely coagulated.  I stored it in the refrigerator, but when I picked it up it was wet, making me think it wasn't sealed properly.  Should I just add more next time or has my rennet gone bad, or is it just hit-or-miss?  Is there a way to test rennet on a test batch?

Note: It is the same recipe.  I am making feta with half ultra-pasteurized goat milk and half pasteurized, non homogenized cow milk.
« Last Edit: April 18, 2017, 10:35:19 PM by SteveScott »

Online 5ittingduck

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Re: Has my rennet gone bad already?
« Reply #1 on: April 18, 2017, 11:23:59 PM »
Check the expiry date.
I had the same thing happen and it was only days out of date after it had worked fine for ages.
If you are in doubt about the leakage factor, get a new one.  In the scheme of things they are not too expensive, and you will have eliminated one source of potential trouble.

Offline Gregore

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Re: Has my rennet gone bad already?
« Reply #2 on: April 18, 2017, 11:31:37 PM »
It is unlikely to go  that bad that fast, but maybe it was already well past it's good date and was on a fast down hill slide .  If that is the case your next rennet will be much stronger so unjust for that.

How long  did it sit in the  mix water before you added rennet to milk ?

More than 10 minutes can have an effect , more than 15 can have a big effect

Acid not dropping far enough can have an effect and so can the milk ; milk changes through out the year a little .

And if milk is higher ph it has more buffers against acid drop , thus longer to start the acid dropping .

Once I had a milk so good it took more than 2 hrs to get a drop of .2

Try again but with just 25 % more rennet , then if still not working well then yes get more .

Online 5ittingduck

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Re: Has my rennet gone bad already?
« Reply #3 on: April 19, 2017, 02:24:04 AM »
And forgot to mention another common trap, dilution of rennet with chlorinated water wrecks it.

Offline Chetty

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Re: Has my rennet gone bad already?
« Reply #4 on: April 19, 2017, 09:00:47 AM »
If I use tap water from my cheese room I add some milk to the water before adding the rennet.  The milk binds with the chlorine and keeps it from killing the rennet.  How long did you stir after adding the rennet?  I usually stir for one min and then try to stop the milk from moving as fast as possible. 

Offline Dorchestercheese

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Re: Has my rennet gone bad already?
« Reply #5 on: June 24, 2017, 08:17:11 PM »
I had a similar issue today..
I've been using raw milk and the rennet was setting it quicker than the recipe said but i was happy with the results.  Today two weeks later...I've had flocculation times of 80 minutes and i made two sets of cheese today.  Both times same issue..it did set but took a lonnnnnnggg time.

Could it be the milk, something the cow ate?  I just bought this rennet two months ago..it says 8 months from delivery.

Offline AnnDee

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Re: Has my rennet gone bad already?
« Reply #6 on: June 30, 2017, 05:57:22 AM »
Sometimes if the cow has had antibiotic treatment recently, it can interfere with coag.
Ann

Offline Bernardsmith

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Re: Has my rennet gone bad already?
« Reply #7 on: June 30, 2017, 07:36:53 AM »
But the OP asked if there is any test to check the viability of rennet. Is there some kind of test that we can use without wasting a gallon or more of milk?

Offline AnnDee

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Re: Has my rennet gone bad already?
« Reply #8 on: June 30, 2017, 08:47:10 AM »
But the OP asked if there is any test to check the viability of rennet. Is there some kind of test that we can use without wasting a gallon or more of milk?

Oops sorry, what I would do is to test the rennet on a little bit milk, like 500ml or so, bring it to 30-32 and mix in rennet (the amount will be as much as needed to coagulate 500ml). Let it flocc, don't forget to time it.
Ann

Offline Bernardsmith

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Re: Has my rennet gone bad already?
« Reply #9 on: June 30, 2017, 04:55:24 PM »
Aha! Thank you.

Offline Gregore

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Re: Has my rennet gone bad already?
« Reply #10 on: June 30, 2017, 10:55:31 PM »
I think some where on the old posts  there is a quicker way to test rennet . I have never needed to test mine so I never payed much attention to how they did it but I am sure with a quick search it can be found . It should be pre 2014 possibly closer to 2010 to 2011 .

Offline Dorchestercheese

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Re: Has my rennet gone bad already?
« Reply #11 on: July 17, 2017, 09:10:20 PM »
To carry on the conversation an example from this weekend.
I picked up some raw milk and made cheese Saturday and again Sunday.
4 gallons each day
Saturday pH start at 6.87 with 3/4 tsp rennet animal liquid diluted in 1/3 cup of water boiled Friday night, diluted 1 minute before addition to milk.
Set target was 45 minutes
Flocculation (tiny plastic dish stops spinning) at 30 minute
Multiplier specified 2x flocculation time
Cut at 60 minutes not 45 minute - pH 6.59

Next day 4 more gallons pH 6.79 with 1/2 tsp rennet
Target time 45 minutes with 3.5x flocculation time target
Took 33 minutes to flocculate which means 110 minutes total time for set not 45 minutes.
Of course the longer set the pH is at 6.46 when I cut at 90 minutes of set time.
Of course this is 45 minutes longer than target...

When you face this what happened?
Longer set time means pH is continuing to drop and depending on cheese the desire more moisture is being trapped in cheese because of long set times
So milk can change over the year or season..
Do I use more rennet to hit the target time ...
Because once the cheese goes lower than the desired pH at this point it's going to hit the other pH markers earlier too..
For example when making cheddar do you then stop when the pH marker is reached or texture when cheddaring..
My pH mark was met quick during cheddaring because I was so low coming out of the curd cutting step

Any recommendation for text on cheese chemistry?

Offline Gregore

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Re: Has my rennet gone bad already?
« Reply #12 on: July 17, 2017, 11:24:53 PM »
Yes more or less rennet through out the year , that is the advantage that daily making gives the pro .

I use 19 drops for 3 gallons raw milk when the milk is at it's best , and 17 when is is less so , that gives me about. 15 minute floc. Which is optimal .

Still have yet to nail down the exact amount for the commercial pasteurized stuff.

If and when I have had curd ph dropping faster than I like I have either  taken out whey and added water to the cut curds , or lowered the temp during molding , depending on type of cheese and when things started to go down hill too fast .

In your case. Would have gone for the whey / water , and then if that was not enough a little lower temps

Offline awakephd

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Re: Has my rennet gone bad already?
« Reply #13 on: July 18, 2017, 08:34:12 AM »
Are you ripening the cheese before adding the rennet? I think I remember correctly that rennet works more quickly at lower pH levels. 6.8-ish seems rather high to me ... but then again, all I have to work with is store-bought P&H milk, and I've never seen the pH of that start out above 6.7.
-- Andy

Offline Gregore

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Re: Has my rennet gone bad already?
« Reply #14 on: July 18, 2017, 11:21:01 PM »
Yes lower ph the quicker the rennet works and the more curds per volume of milk , all the way down to 5.9ph or so .