There are many parts of the cheese making process that determine the type of cheese we create, such as the starter we add and the milk we begin with, but one of the most crucial is the way in which we cut the curds.In this extended article I’m going to look at why it is that cutting curds correctly is such a crucial part of determining the character of a cheese, how we can ensure that we do it uniformly and the method I use to deliver a consistent cheese texture.
Creating the curds themselves begins, in most recipes, with the addition of a coagulant. For the purposes of this article it’s assumed that this is rennet – rather than an acid – in either its animal or vegetable form.
Each cheese recipe will call for a certain amount of rennet to be added to milk at a specific temperature which is then left for an allotted period of time.
(Timing your curd set is fine for the hobby cheese maker, but there are variables at work here, such as rennet concentration and the makeup of your milk that can affect how long it takes for setting to actually occur. A more scientific way of measuring curd setting is the flocculation method which is covered in detail as part of the ‘experienced’ section of the website.)
Once we have allowed the right amount of time to pass, we need to check that our curds have actually formed. When you examine the pan, you will almost certainly see the familiar mass of white curd sitting in a pool of whey, but what is not known by just looking is whether the curds are firm enough to be cut, which is why we perform a clean break test.
The clean break test is self-descriptive. When we put a sterilised knife or spatula into our curds and turn it to an angle of 30-45 degrees, we want to see the curds break cleanly beyond the blade and the hole created fill up with whey. If this test is positive we can be assured that our curds are ready to be cut, whereas if we don’t see a clean break and instead get an edge that is soft, ill-formed or gooey, then we need to give the rennet a further 15 minutes to firm up the curd before repeating the test.
The size and set of our curds is a significant determinant of the type of cheese we produce. Looking through your cheese recipes, you may see some that call for curds to be curt as large slabs with others instructing you to use a whisk to break the curds into tiny pieces. The size of a curd cut is crucial to a finished cheese simply because of the amount of moisture they contain. In the article on how rennet coagulates cheese we saw that curds are actually a gel-like form of milk, casein micelles clump together around other constituent parts of the milk, including fats and water, trapping them inside a curd prison.
When thought of in this way, it is easy to see that the more cuts we make, i.e. the smaller the curds, the more places there are that the water (effectively, the whey) can escape from its casein confines. Conversely, in larger curds, the water trapped in the centre has no escape route and ultimately remains part of the cheese that is formed.
High water content cheeses are the soft cheeses such as brie and camembert, which have a larger curd cut that the firm cheeses such as cheddar and parmesan. Of course, there are other factors at play (the diversity of things that affect the finished cheese is what makes cheese making at home so appealing!) such as whether the curds are scalded, or heated after cutting, which further expels moisture from them, and the force with which curds are put into a mould – pressing removes yet more whey.
The third factor which influences moisture content is time, or, more specifically, aging. Part of the maturity of a cheese comes from the slow loss of moisture over time when stored under appropriate temperature and humidity in a cheese cave, although this only works for cheeses that are relatively low moisture when formed, since high moisture cheeses are much quicker to spoil and won’t be kept for months or years post production.
Let’s return to our curds sitting in the pan on the hob. We’ve carried out the clean break test and achieved a successful result, so we’re now ready to actually cut our curds. What we desire is curds that are as uniform in shape as we can get them, which for us is something close to a cube (actual cubes are all but impossible to create in the confines of a saucepan with a knife). The uniformity of size is important, as it means there will the same amount of trapped moisture in all of the curds which, in turn, will deliver us a finished cheese of uniform moisture. If we imagine the alternative of a cheese made with large wet bits of curd and small dry pieces too, where each bite differs in texture from crumbly to smooth, it’s quickly apparent that uniformity is best.
To create our curd cubes is relatively straight forward but requires a steady hand. Take your knife or spatula and cut from one side of the pan to the other (I usually begin in the middle, as this gives me the fullest length cut as my starting point to measure from), making sure to cut from top to bottom all the way across, even at the very edges of the pan i.e. make sure you don’t catch yourself lifting the knife out of the pan as you approach its edge, or you’ll end up with larger curds there.
When your first cut is made, you’ll notice that the line it leaves is very distinct so, from that line, measure the required width of your curds (by eye is fine, rulers are not required) and make another cut side-to-side and top-to-bottom parallel to the first, and repeat until you’ve covered the width of the pan. At this stage you’ll have a series of parallel lines, so the next step is to turn your pan 90 degrees and do exactly the same cuts again. When you’ve done this the top of your curds should be a mass of squares and look like a chess board.
In your mind’s eye, you can probably see that what you’ve created below the surface is a number of square columns all standing in the pan next to each other. The next cuts need to slice those columns into small pieces. So, using the chess board lines that you’ve already created, put your blade back in the first one at an angle of 45 degrees and cut. This action severs the columns below the surface of the curd and they will quickly begin to collapse. Working quickly (but calmly and smoothly) move to the next line and repeat the angled cut and continue doing so with each line to the other edge of the pan. Turn the pan 90 degrees once more and make the same angled cuts down through the curd in the
second set of lines you have.
This is quite tough to describe using words, so take a look at the diagram provided at the bottom of the article, which hopefully makes things clearer.
If it all sounds a bit much, take heart that there is a tool available that makes curd cutting so much simpler, imaginatively called a cheese curd cutter. It is an open panel of ‘blades’ at set distances apart from each other that is simply dragged through the curds creating cubes as it goes. Whilst this sounds great, they are generally not adjustable (so only make one curd cube size) and are too large for the home cheese maker – but if you set up your own artisan producer, you might want to investigate further…
Back in the world of saucepans and hobs, be happy that once all that cutting is complete, you have moved past the most difficult part of forming your curds and should have a pan full of approximately equal cubes. Your recipe might call for them to be left for a period of time before stirring, or for stirring to take place immediately. Whenever that first stir happens, it is your opportunity to look out for rogue pieces of large curd (there is always at least one in there because of the logistics of cutting in a pan) and cut them down to the required size.
With curds formed, this extended article must come to a close, but we are not by any means finished treating our curds yet. Indeed, depending on the cheese you’re making, the recipe may call for further curd treatments such as cooking, scalding or washing, and it is these that we’ll examine further in the next article.