Dry curing is just the same as brining – but without the added water. This method has been widely used as a means of preservation since ancient times. Our forebears may not have understood the chemistry, but it is relatively simple: almost all meat contains a high percentage of water, which must be removed to prevent it from spoiling. Salt rubbed into the meat draws out the water and retards the growth of enzymes and microbes.
How Dry Curing Works
If we look at our food a little more closely, we see that it has a very complex structure. When we are curing food it pays to understand the action of enzymes and micro-organisms as well as the structure of the meat. Enzymes are specialized proteins that can help produce to ripen; however, they can also trigger the rotting process. The simplest way to stop enzymes is to cook the food or to freeze it. Moulds, yeasts and bacteria are all micro-organisms that are sometimes harnessed to add flavour (just think of some ripe cheeses), but if left unchecked they may ruin your food.
The resistance of different types of bacteria to salt varies. For example, salmonella is inhibited by salt concentrations as low as 3%, but staphylococcus survives in much higher concentrations. The curing process must provide sufficient cure to effectively protect against unwanted degradation. It may sound like a battlefield, but there is the added advantage that the flavour is enhanced as well, especially if extra herbs or spices are added.
Good old-fashioned salt is the key ingredient, though it acts less harshly as a dry cure if used in a coarser form, so rock, kosher or sea salts are preferable to table salt. Curing does not happen instantaneously – it takes time for the salt to penetrate the meat and draw out the moisture. It is also worth remembering that the meat is vulnerable during the curing process, so it must be kept in a cool place. It was no accident that curing used to be most common at the start of winter, when the autumn reserves had diminished and the cool days had started. Using salt alone can dry out the meat and leave it hard and salty, and it often loses its colour. To counteract this, sugar is usually added.
- It is essential to buy good meat or fish.
- Clean everything that you are going to use very carefully.
- Trim the meat of excess fat and unwanted bits prior to curing.
- Rub the salt into the meat or fish thoroughly, especially into any creases or crevices.
- Use a crock pot, plastic food container or hardwood box or barrel.
- Keep the meat or fish cool while curing.
- Curing takes time, so be patient – good things come to those who wait.
The Essential Cure
To make a basic dry cure, mix salt and sugar in the ratio 3:1. You will need at least 100g (3½oz) of cure per 1kg (2lb) of meat or fish. Then add your spices or flavorings. It makes sense to cure more than one cut of meat or fish at a time. For example, for 5kg (11lb) meat you would use at least 500g (1lb) of cure – 375g (13oz) salt and 125g (4oz) sugar.
You can customize your cure with almost any flavourings, but lightly ground spices will impart more flavour than herbs, especially if the spices have been lightly toasted before grinding to release their oils. Use aromatic spices like dried chillies, star anise, black peppercorns and cardamom pods. Instead of sugar you can add treacle, honey or even molasses.
The Curing Process
You will need a plastic tub, a crock pot or a hardwood box or barrel. The container must have drainage holes and must not be made of metal. Rub the individual joints of meat or pieces of fish thoroughly with the cure, taking care to include any crevices and areas around the bones. Spread a good layer of cure at the bottom of the container, then put in the largest pieces of meat or fish, skin side down, trying not to let them touch. Cover with a layer of cure, then add a second layer of meat or fish. Cover with more cure. Put a lid on the container, preferably weighing it down on the meat. Place it on a drainer or tray, and store in a cool place for 4 days, making sure that the liquid that comes out of the bottom of your container can drain away.
After 4 days remove the meat from the container and repack it all, making sure that it is well covered with the cure. If some areas appear to have been left bare, rub the cure well into them thoroughly. The meat should now remain in this second cure for 2 days per 1kg (2lb). Make sure you put the smaller pieces on top, because they do not need to cure for as long as the larger ones and you can take them out first.
There are lots of variables when you are determining the length of curing:
- If the weather is cold, the curing can sometimes take longer, and if it is warm the curing time is shorter.
- Thick cuts need more curing time than thin ones.
- Personal taste is a factor.
Dry Cures and Timing:
- Duck, Breasts (about 1kg/2lbs): 100g salt, 30g sugar, 6 days curing time
- Pork, Belly or Back (2kg/4lbs): 200g salt, 8 days curing time
- Leg of Pork (about 6kg/13lbs): 600g salt, 200g sugar, 21 days curing time
Also from Curing and Smoking: Dry-Cured Duck Breasts Recipe
Reprinted with permission from Curing and Smoking: Made at Home by Dick and James Strawbridge and published by Firefly Books, 2012. Buy this book from our store: Curing and Smoking.