What is Emulsification?
Emulsification essentially means 'bind' or ‘blend’. The key to a good sausage is for the meat (protein), fat and liquid to all ‘emulsify’ - or blend into one another.
Good emulsification or binding mostly comes down to getting the right meat/fat/water ratio and HOW you make your sausage - particularly the griding and mixing stage. Grinding your sausage meat and fat is the first part of the emulsification process. We recommend grinding your sausage mix twice, which will help the emulsification process.
Then you should give it all a good mix, preferably by hand. As you mix, you will notice the texture of the mixture starting to change. The mixture starts to ‘bind’ as the protein starts to absorb the fat and water. This is the process of emulsification at work. The mixture will become sticky and form a more uniform mixture with less visible ‘bits’. This sticky paste is called a ‘farce’. You know your mix is ready when you can grab a spoonful in your hand and it will stay stuck to your hand when you turn it upside down. If it doesn't stick, you need to mix some more.
The more you mix, or emulsify, your sausage mix, the more smooth and uniform your sausage will be, both visually and texturally. If you pureed the sausage mix to a fine paste, you would get a highly emulsified, ‘smooth sausage’ eg a hot dog. These sausages are sometimes called an ‘emulsified sausage’ even though some level of emulsification occurs for all sausages. If you only grind your sausage once or use a coarse grinding plate and/or don't create a farce you will still have lots of visible 'bits' in your sausage mix and your end sausage will be more coarse/crumbly when cooked.
Here are some common emulsification agents or fillers:
Eggs
Egg whites are very lean but extremely high in protein so they are an excellent emulsification / binding agent, especially for pureed sausages. Whole eggs have more fat (11%) and will also act as a binding agent. They will also add a creaminess richness to your sausage.
Cream
You can also use cream in sausage recipes to add fat, flavour and creaminess. You can substitute water for cream.
Other fillers
Bread, rice or rusk (baked breadcrumbs) are common ‘fillers’ for sausages. A common misconception is that they are great binders in your sausage, but they are primarily used by sausage manufacturers to make the meat go further, not to help the sausage bind.