GENERAL CHEESE MAKING BOARDS (Specific Cheese Making in Boards above) > STANDARD METHODS - Making Cheese, Everything Except Coagulation

Rennet Curd Setting Times: Flocculation Technique

(1/5) > >>

makkonen:
I'm fascinated and a bit daunted by this flocculation point talk. As someone who is far too laissez-faire with his curd cutting and curd healing times, I'd really love to have a better sense of how this factors into the process.

I assume flocculation and set times (and thus, the multiplier) are determined primarily by pH, and secondarily by rennet strength. Is there anything that goes into this determination that can't be controlled by tightly monitoring pH ranges? I can imagine that further development of the curd before it starts to expel whey leads to changes in texture and moisture content -- I just don't know how, or to what extent.

Cutting the multiplier in half if the wheels can't hold their shape -- this really turns me upside down. OK, working through it, I'm guessing this means that waiting longer to cut leads to less whey expulsion at equivalent pH, and thus a higher moisture, softer curd (which then is more likely to sag and fall apart). Maybe I've answered my own question here. But any other insights would be much appreciated.

linuxboy:
Hi Mako. I'll try and shed some light on the flocculation question, but it is rather technical. In a sense, you're right that pH and amount of rennet affects it, but that is just part of the story. I'll try to demystify it.

First of all, recall that curds form due to chymosin action in two stages. The first stage is when chymosin (and other enzymes in rennet) cleave the k-casein on the micelles to expose available calcium ions. The second stage is when the calcium ions connect the micelles into large strands to form a lattice which can trap the fat, water, solids, etc.

The point of flocculation is when somewhere around 75% of the micelles have been cleaved through enzymatic action. The key factors that determine cleaving are the same as with other enzymes, specifically: ionic concentrations, pH, and temperature.  That is why it is vital to use a flocculation multiplier. Milk varies through the year based on lactation cycle, time of year, type of feed, stress, etc.

The time you let the curd set based on the multiplier determines several things, most important of which is rate of whey expulsion. Simply put, the lattice that forms after micelles connect retains water, and the longer you wait, the slower the curd will let go of the water from the lattice. The curd size also influences the rate. That's why for brie, you use twice the multiplier as for a hard cheese like cheddar and also cut the curd into very large strips. You did answer your own question :)

I really love the European method of using flocculation time. Here's one more trick to tell flocculation point. Take an empty bowl that floats, sanitize it, and float it on top of your milk after renneting. Then spin the bowl. At first, it will spin easily. At the flocculation point, it should barely spin or not spin at all because there will be a lattice matrix formed, and in its early stage.

FRANCOIS:
In simpler terms floculation is the point of surface gelling in the milk.  The spinning bowl is a good method and is how we do it.  Floculation is not necessary related to a cetain pH or rennet amount as other variables effect the floc time.  In most hard/semi-hard recipes floculation occurs in 10-12 minutes unless there is something off in your milk, which does happen if you are using raw milk. 

The longer you wait the more whey is loosly bound in the curd, think chevre/creme fresh/brie etc. which have very long set times between rennet and cut.  It's not quite the same  process becasue you are adding much less rennet to those but the principle is the same. 

Floculation is better method than clean-break for two reasons:
1.  Clean break is imprescise since curd will give a clean break at 1 hr, 2 hr, 3hr....
2. Measuring the floculation time and using a multiplier will help ensure you always have a consistent curd, no matter how your milk changes (within reason).  If somehting is off with the milk, it will show up with this method.

My two cents anyway...

zenith1:
which brings up the next question, how is everyone determining the point of flocculation?

linuxboy:
I use the spinning bowl technique. I also keep a log and plot trend lines for flocculation times during various times of the year. Helps me to estimate when flocculation should happen and then confirm visually.

Navigation

[0] Message Index

[#] Next page