Healing scalding and washing curds

This article follows on from Cutting Cheese Curds Properly and in it we’ll look at all the curd treatments that can happen between cutting and draining, so: healing, scalding, and washing.Healing
Perhaps the strangest of the post-cutting curd treatments is healing, and it’s strange because it doesn’t feel like a treatment at all as it’s the point in the recipe where we’re told to leave the curds alone for a period of time, or let them ‘rest’. What’s actually happening here is that we’re controlling two very important aspects of the cheese making process by allowing the curds to form a skin, which is actually the edge of the milk-gel becoming smooth and firm.Healing is a very appropriate word for the process that is going on here. When we first cut the curd, it is a very fragile material and needs time to ‘heal’ from the cutting before we can go on to manipulate it further. As soon as the cut is made, the curd pieces all start to form a skin on their outer edges and it is this that is vital to our cheese. If we start to agitate the curds (say, by scalding or stirring) before they are healed, then they lose small pieces of fat and protein called fines which will go through our cheesecloth and so are not recovered when separating curds from whey.If we create too many fines then we reduce the quantity (yield) of cheese we create from any given amount of milk, and we upset the balance of fats, proteins and moisture in the final cheese, which will fundamentally change the character we are trying to achieve.

If one aspect of healing time for the curds is reducing fines, the second important element of healing cheese is the impact it has on moisture levels. Academic studies have shown that longer healing times reduce the amount of moisture lost from the curds which, as you know well by now, is a vital element of determining the type and quality of the cheese we end up with.

One important lesson to take from all of this is that as you strive to produce better quality cheese, or even just deliver consistency from one batch of cheese to the next, is that even the seemingly trivial parts of the preparation, e.g. ‘leave the cut curds to rest for 10 minutes’ can have a significant effect on the end result.

Scalding
In a similar vein, we need to think about why we scald the curds. Scalding (or cooking) is quite simply the process of leaving the cut curds in the whey but under a higher heat than they were formed at and either with or without gentle (so as not to create excess fines) stirring.

If you think that this process might also be about moisture levels, then you’d be right, but that is only part of the answer. It’s true that increasing the heat of the surrounding whey does induce more moisture to leave the curds. If the curds have been given a short amount of healing time, they will lose even more moisture during the scalding phase, deliver a lower yield and lose more fat to the whey than if they spend longer resting.

The moisture loss is most effective if temperature is increased very slowly; the faster the increase in temperature, the more moisture will stay trapped in the curds, never to be released. You may also find that rapid increases in heat causes your curds to form a thicker ‘skin’ than desired, adversely affecting the finished texture of the cheese.

This is another great example of why following recipes closely and, as you become more proficient, taking control of your own cheese making though monitoring variables such as rate of temperature increase, is so vital to the quality of your finished cheese.

There is a third variable that scalding impacts: acidity levels. The amount of acid in your cheese (its pH) directly impacts the flavour of it; too acid and it’s going to be bitter (I have done this numerous times!), not acid enough and it will be bland.

The acidity of cheese is due to bacteria from our starter culture converting lactose into lactic acid. If left to their own devices, those bacteria will just keep doing that until the lactose has all gone. One way to stop them creating more acid in your curds is to, literally, cook them. As the temperature moves higher, past around 38C, the bacteria slow down their consumption of lactose. By the time we get to 44C, no more acid is being created and, at around 50C+, the bacteria die – obviously meaning they can’t resume acid formation once the temperature reduces again.

In the advanced articles, we’ll be taking a very close look at acid measurement and control during cheese making.

Washing
Finally, let’s consider washing our curds. Washed curd cheeses, like Edam and Gouda are made by removing the some of the whey from around the curds (after scalding) and replacing it with fresh water at an appropriate temperature. This literally washes away some of the lactic acid from the curds and creates a sweeter finished product with a smoother texture and milder flavour. Perhaps unexpectedly, it also drains lactose (milk sugar) from the curds, limiting the food supply for the bacteria and consequently reducing the amount of acid that can be produced.

Washing the curds is often done in stages, i.e. your recipe will call for an amount of the whey to be removed and replaced with warm or hot water for a few minutes, before more is removed and replaced. This may take place in a number of stages, until a certain temperature (and/or pH) level is met.

At this stage, we’re ready to move on to draining, shaping and pressing curds. So, to recap this and the cutting the curds article:

• Once formed, uniformity of curd size is important
• Healing the curds impacts the moisture, fat and protein content of the cheese, as well as the yield
• If the curds need cooking or scalding, the time and temperature affect both moisture and acidity
• Curds are washed in Gouda-like cheeses to give smoother texture and milder taste

The big lesson to take from these two articles is that consistency – as much as you can achieve in your kitchen – is one of the big secrets to success in cheese making.

If you’ve not read Part One of this article, then go to Cutting Cheese Curds Properly now.