What Is Flocculation? A Method For A Better Curd

As we all know, one of the most important steps in cheese making is getting a good curd set up.

Without a good set up, most cheeses won’t ever become what they should be, and some won’t become anything much at all. Apart from pig or chook feed, or compost waste that is.

Using the suggested coagulation times in a cheese recipe is reasonably reliable for getting a set, but not overly precise in terms of getting the best set to achieve the ideal cheese profile.

Sure, you might end up with a Gouda after all your hard work, but does it have the texture and moisture that you know it should have? Do you have a cheese that could give the all those store bought wedges a run for their money.


Flocculation Method And What Is Flocculation?


And to make things more interesting, the many variables in just the combining of milk and Rennet, such as Rennet strength, amounts and viability, seasonal and commercial milk variations and heating temperatures, let alone room temperature and acidity levels, can send things somewhat awry.

As you continue with your cheese making journey you’ll likely come to a point where you will want to understand more advanced methods that will allow you to perfect your ‘starter cheese profiles’. Or maybe you just want to avoid any more vats of gloopy unset curd from having to be disposed of.

Either way, the curd set up step in cheese making can become a lot more reliable and you can gain more control over achieving a preferred firmness of curd with what is known as the Flocculation Method. But first I will explain what flocculation is.


What Is Flocculation?

I heard about the flocculation method and began using it for my home cheese making then I thought to myself what is flocculation?

Flocculation is when fine particles are caused to clump together. This is called a “floc”. The floc may float to the top of the liquid which is called creaming or sink to the bottom of the liquid which is called sedimentation.

What Is The Flocculation Method?

The Flocculation Method is a way to test the point of coagulation, when the solids begin to separate from the whey.

Using this method to define the point when coagulation occurs, and then using a standard multiplier depending on the cheese type (listed below), you can predict the optimum curd set point for the type of cheese you are making.

These optimum set points dictate how much whey is bound in the curd, therefore contributing to the moisture content and texture of your cheese.

A soft cheese typically has a higher flocculation time, and a larger curd cut, keeping more moisture in the cheese.

A hard cheese on the other hand has a lower flocculation time, and a smaller curd cut, releasing more whey for a firmer, drier cheese.

It might sound complex, but the aim of Curd-Nerd is to try and de-mystify the sometimes technical aspect of cheese making and keep things reasonably simple, so here are the steps of what is actually a pretty simple method when you break it down.


Flocculation Method – Step By Step

Add your Rennet to the milk, and mix thoroughly.

Leave your Rennet to work for 5-6 minutes then take a sterilised bowl (I use a small glass bowl) and place it onto the surface of the milk. The bowl will float on the top of the milk.

Spin the bowl gently and notice that it freely rotates in the milk. The spinning of the bowl is why this method is also sometimes referred to as….wait for it…..’the spinning bowl method’.

Continue to spin the bowl regularly, every minute or so. You will notice the bowl will slowly start to resist spinning in the milk as freely as it did when you started

Eventually the bowl will become almost totally resistant to spinning without force, and you will also notice that a dent has moulded in the solid curd mass forming underneath the bowl.

This is the coagulation point and it ideally occurs at about the 12-15 minute mark.

This video shows the first stage of the Flocculation Method. Notice that they push the bowl rather than spinning it. Either technique gives the same information.


Now depending on the cheese you are making, you need to take the number of minutes it took until coagulation and multiply it by one of the factors below for your ideal curd strength:

Flocculation - Flocculation Method And What Is Flocculation?


The higher the multiplier, the more moisture is held in the cheese. So cheeses such as Brie and Camembert have a higher multiplier than say Parmesan.


Now you can work out your total Rennet Set time –

Coagulation time x multiplier = total time from Rennet addition to cut


So if you have a coagulation time of 14 minutes and a multiplier of 3.5 for Cheddar you would have a total of 49-50 minutes Rennet set time.

When using the Flocculation method it is a good idea to keep a log of the set times you achieve with different cheeses. This will give you an indication of what to expect and then if you find it changes, you can start to assess (and better understand) if product, seasonal or environmental factors are having an impact on your cheese making process.


Flocculation Method Discrepancies

Common discrepancies that occur with the Flocculation method are either too short a coagulation time (less than 10 minutes) or a coagulation time that is too long (anything upwards of 20 minutes). These discrepancies can occur due to any of the variants mentioned above but can often also be easily remedied by adjusting the amount of Rennet, up or down, to achieve the preferred coagulation point of between 12-15 minutes.


So hopefully, if I’ve explained this clearly enough, you can see that the Flocculation Method is not overly complicated but it does take a little extra attention, thought and patience.

It’s well worth it though to have more control over how your Rennet performs with your milk and to feel more confident about getting a better curd set, and a more superior end product.


Give the Flocculation Method a try with your next make and let the community know how you go. If you have any issues, we can work them out together. Join the discussion over at the Curd Nerd Forum. We would love to hear from you!


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16 thoughts on “What Is Flocculation? A Method For A Better Curd

  • 20/02/2012 at 7:55 am

    Thanks for sharing this. My next project will be some camembert and I’m going to try this method.

  • 20/02/2012 at 11:50 am

    Thank you for this information. I wish I would have read it before we started our cheese. WE took two gallons of non-homogenized farm fresh milk, followed the instructions, heated to temp, blah blah blah let sit for an hour after rennet and nothing. No curds. No nothing. I will be happy to send you the instructions we used but I’m not sure where we went wrong? Too much bacteria in the milk? Too little? Not the right temperature?

    • 19/03/2012 at 10:47 pm

      Hi Marcy

      Thanks for visiting!

      My first questions would be whether your Rennet is still viable? And if you are using the right amounts as per the manufacturers instructions.

      Acidity and temperature could also contribute to your problems but would more likely cause a weak curd rather than no curd at all.

      Have you had any success before or since with the ingredients you are using?

  • 23/10/2012 at 11:55 am

    Hi Allison

    I definitely find that different seasons, produce different results and flavours in our cheese. This is of course all down to the quality of feed for our milking animals, and also any additions that farmers might be applying during ‘off’ seasons and calving seasons.

    I personally find the more buttery, sweet cheeses and the fresh cheeses are truer to type when made during the spring, where as longer aged, firmer cheeses don’t seem to be as impacted and can be made without too much variation during the winter, and in warmer months.

  • 16/01/2013 at 10:55 am

    Thanks for this great information. I have one question. Once you get the flocculation time and do the calculation do you use total time including the time to get the flocculation or once you get the calculation you then set the time from there.

    • 09/02/2013 at 2:39 pm

      Hi Avril

      You’re absolutely right. Coagulation time x multiplier = total time from Rennet addition to cut

  • 11/02/2013 at 5:27 pm

    Not being such an expert, I’m not sure what type of cheese mozzarella is and therefore what multiplier to use for it. Can you help me out?

    • 21/05/2013 at 11:30 am

      For Mozzarella, use a multiplier of 4.

  • 29/05/2013 at 10:16 am

    Today was my first attempt to try making Feta. It was an absolute flop. I kept the temp at 210 per the candy thermometer for upwards of 20 minutes. I never acheived any curds or whey. The Rennet could be old. It isn’t dated and I know I’ve had it awhile. I want to learn this. It sounds very interesting but I am a complete novice. Help!

    • 17/06/2013 at 9:27 pm

      The age of your Rennet could definitely cause you problems, if it is old and out of date. Also, the age of the milk, the amount of Rennet and your temperatures could all play a part.

      But my biggest question is, at what point are you maintaining a temperature of 210? This is very high, and I’m confused about which part of the process you are applying these temperatures to.

  • 05/06/2013 at 6:31 am

    I’ve been wondering about the different types of Rennets. There seem to be several and the Junket are the most available in the supermarket but have other ingredients with it. Do you think that when using the Junket tablets you might need to use more because it is diluted? Could these tablets have an outcome on my curd process? Thank you in advance and thank you for this wonderful site. So glad I found it :o)

    • 17/06/2013 at 7:28 pm

      Hi Kitty

      Thanks for your question. I personally have not used Junket so can’t really comment on the dilution of this product. I do know that with similar products we have here (Renco), the solution is not as strong as Rennet supplied purely for cheese making, and is designed more for dessert making etc. Therefore, you would need to increase the dosage.

      My preference is to stick to Rennet products (calf or goat) supplied by cheese making supply companies. But this can come down to cost and ease of access for some home cheese makers.

  • 17/07/2013 at 1:48 pm

    You have a great web site so easy to follow.. Made my first Camembert yesterday and looking good.Try a Colby next.

    • 17/07/2013 at 3:49 pm

      Hi Clive

      That’s awesome! Thanks for the feedback and good luck with the Colby. Let us know if you have any questions.

  • 21/09/2016 at 3:40 pm

    Awesome! I have been making cheese for a few months now and have wondered the best way to figure out how long to let my curd set! This is an excellent explanation and I am very excited to use it on my Havarti this weekend! I wish I had it for the past several months of cheese making I have been involved in! I have had pretty great luck with my cheeses so far and am sure the information contained in your blog will help immensely! Thanks for all the great information you have shared!

  • 12/10/2016 at 12:48 am

    Hi, I am new to Cheese making. When I added citric acid(1/2ts) to 1 litre milk(pasteurized) and heated to 95F , I noticed slight curdling(small grains. Then when I added chymosin powder 1/8 ts, it didn’t coagulate. So I added another 1/4 ts but still no change.

    What could have gone wrong?

    What can go wrong if excess of chymosin powder is added?
    Is it necessary to rest the mixture of chymosin powder and water for 5-6 minutes before adding to milk?
    Is there a method to test if the chymosin powder that I am using?

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