Author Topic: Coagulation, Rennet - Flocculation Time Method Discussion (& Rennet Pre-Dilution Amount Discussion)  (Read 8639 times)

bonk

  • Guest
Hi All,

i hope someone can help me with a question.  i've had a few cracks at making cheese but i think i'm adding the rennet wrong or incorrectly as the curd formation i get is nothing like the ones in the books and here on the website.

i'm only able to use store bought homogenized milk and got some calcium chloride to see if that will fix or help to correct my issue.

the issue i have is when i add rennet i dilute it in 10 times its volume with cooled boiled water and try and spread it over the milk and stir it for about 2 mins.  i can see the milk start to curdle and i stop and leave it sit for about 1hr. i added 2 ml of calcium with 20 ml of water and 2ml of rennet with 20 ml of water to 3L of milk.

but i don't get a very uniform looking set milk, i get this small weird looking shape that floats in the middle of the pot.  And i think i'm not doing it right.      it looks like a dense cottage cheese thing.

would the method on the site be better, the whisk while pouring it in method ?
not enough rennet or not enough calcium chloride?

wharris

  • Guest
I only stir for about 1 min.

I start checking at about the 35min mark.  I am usualy cutting at about 40-50min.

What kind of rennet/CaCl  are you using? 

Sailor Con Queso

  • Guest
Sounds like you are letting it set too long and the curd is pulling away from the sides of your pot. You should read up on flocculation and flocculation multiplier. This is WAY more accurate than just using time.

Here are a couple of resources:

www.dbicusa.org/resources/dianamurphyartisanpaper.pdf

http://cheeseforum.org/forum/index.php?topic=1880.0;wap2

Alex

  • Guest
Bonk,

Be sure you add the rennet as last ingredient and do not stir more then 30 sec.

linuxboy

  • Guest
Your dilution should be closer to 30-40x in cold water, and stir up and down 10-15 strokes to incorporate everything.

wharris

  • Guest
So, for double strength veal rennet, should i double the dilution?

linuxboy

  • Guest
No, 40x should be OK. Some people prefer a 20-30x dilution for single strength, but 10x is too little, especially for double strength because the rennet is still too concentrated, so when you add it in, you have to stir more to make sure its incorporated. With 10-12 mins until typical flocculation, at 10x that doesn't give rennet enough time to spread via diffusion, meaning it needs to be stirred in thoroughly. The point of dilution is to help with even distribution so you get a nice set, but there's a balance between introducing too much water and not diluting enough. That balance is somewhere in the 20-40x range.

Sailor Con Queso

  • Guest
What's the downside of using too much water for rennet dillution? Isn't it just going to come out in the whey? If you were using a large volume, I could see how that might pull out calcium ions, alter the pH, etc. But we are generally using small quantities of rennet and dilution water.

linuxboy

  • Guest
Using too much water will change the ionic concentration and potentially pH, like you said. This could influence the strength of the curd set. When the chymosin acts on k-casein and when the casein chains join, there's more water in the resulting matrix if you add water. If the casein concentration is already low, and/or if the calcium is already low, the curd will be weaker. If your milk is good, a bit more water should not change things. But if you're dealing with poor milk, such as during the summer when solids are generally lower, the curd may not set as well.

That said, you're right, because rennet and dilution volumes are so low, it shouldn't change the cheesemake much. The extra water will just come out as whey.

Sailor Con Queso

  • Guest
But in bigger volumes like WAYNE  ;D too much could be problematic.

bonk

  • Guest

thanks for all the replies,

Wayne.  i'm not 100% sure, i would say its an animal rennet and the CaCl are both from a cheese supply shop.  i would say they get it from the right place in order to sell for cheese making.

i'll dilute it a bit more around 30% and try that.  just need to get to the shop and try again and see what happens.  I'll also ease up on the stirring and hope that will help get a clean break.

thanks again

wharris

  • Guest
I would love to have a 10 min conversation about flocculation from someone that "gets" it.
I am 99% there,  but I would benefit from a call. 
PM if you have a few minutes.

Sailor Con Queso

  • Guest
Linuxboy's posts in another forum really helped me understand flocculation. Here's a practical explanation. Linuxboy can explain casein losing electrons. :D

1- Add rennet and start a timer.
2- Float a small bowl on top of your milk.
3- Spin the bowl. The bowl spins because the milk has NOT flocculated.
4- Let it sit for probably 8-10 minutes
5- Try to spin the bowl every 30 seconds or so
6- When the bowl won't spin, that's the flocculation time.
7- Every cheese has a multiplier from 2 to 6. There are references.
8- Floc Time x Multiplier = TOTAL time from rennet to curd cut.

Example - Parmesan might use a multiplier of 2.5
If the floc time is 10 minutes then 10 x 2.5 = 25 minutes
So the total time from adding rennet to cutting curds is 25 minutes
Use this time REGARDLESS of what the recipe says.

This takes the guess work out of rennet time to a "clean break". Compensates for changes in milk, rennet, starter activity, ripening temperature, pH, etc. The lower the multiplier, the drier the finished cheese because softer curds at cutting will give up more whey.

hplace

  • Guest
Paraphrasing from American Farmstead Cheese: there are two phases to curd formation: enzymatic phase and aggregation phase. The enzymatic phase is the rennet enzymes cleaving kappa-casein on the surface of the casein particles exposing calcium ions. When around 80% of the kappa-casein has been cleaved, the aggregation phase starts. During the aggregation phase, the casein particles stick together using calcium as the glue. The flocculation point coincides with the beginning of the aggregation phase.

I think the reason for timing the flocculation point is that it tells you the rate at which the milk is forming curd. If the flocculation point takes longer, then the total set time will be longer. So with different milk types, you can maintain consistency in curd moisture and texture.

I wasn't timing flocculation until I read on this forum to float a bowl and spin it. I have used the bowl method several times now and I have found it very useful in determining whether I'm using the right amount of rennet. I reached flocculation point at 5 minutes on one batch of cheddar. That means I would be cutting curd after a total of 15 minutes. The recipe calls for 30-45 minutes set time. I reduced the amount of rennet for the next batch and I got flocculation at 15 minutes. For aged cheese it's good to use just the right amount of rennet to reduce bitterness defects.

So, many thanks to whomever invented the bowl spinning technique!!

wharris

  • Guest
Your first paragraph was well stated and made some things click with me
Thank you.
Cheese to you!