Mozzarella is a Pasta filata type of cheese (Pasta filata is Italian for spun paste or stretched curd)

There are two main types:

1. Traditional Mozzarella

Made originally in Italy, this mozzarella is traditionally made from Buffalo milk and has 48-52% moisture.  This type is made in Australia from cow’s milk and tends to be softer than the mozzarella made for food service and is sold in block or traditional shapes, e.g. pears or plaits. There is normally no draining or cheddaring belts used and the cheese is predominantly brine salted.

2. Mozzarella Cheese for Food Service

This type of mozzarella cheese is a rennet coagulated semi hard cheese variety with a composition range from 45 -52% moisture and 30-50% fat in dry matter. It is predominantly used for pizza toppings and is sold either shredded or grated. It is often made in traditional cheddar plants using cheddaring belts and may include a dry salting step.

As Mozzarella is predominantly used in pizza toppings the main quality attributes relate to functionality once the cheese is melted eg, texture, look and feel. This article will review the impact of moisture variation on the functionality of mozzarella cheese.

Impacts of higher moisture

Negative Impacts

• Proteolysis (i.e. breakdown from long chain proteins to short chain peptides), as moisture levels increase then the rate of proteolysis increases, which results in a more rapid breakdown of the cheese body. This means that the cheese becomes gummy earlier and will not shred as well.
• Increased browning
• Softer cheese body
• Increased potential for shreds to matt back together
• In low moisture mozzarella cheese an extra 1% moisture may reduce the shelf life by 1 month

Positive Impacts

• More cheese i.e. greater cheese yield
• Increased stretchability, flowability
• Less chewy
• Shorter ripening time

Manufacture Time

The longer the make time the greater amount of syneresis (moisture removal from the curd) and thus lower moisture at the end (assuming all other controls such as temperatures, stirring speeds etc. remain constant).  Faster acid production before draining and particularly before rennet addition will assist the cheese to retain more moisture.

Cooking/Cheddaring Temperature

Lowering the cooking and cheddaring temperatures will slow acid development and thus increase moisture levels. However this will also result in an increased make time to reach the final desired pH. Therefore extra starter may need to be used so that the make time remains the same.
Curd Washing

Some manufacturers wash the curd on the draining belts. This will result in extra moisture retention. Generally the lower the wash temperature the more moisture is retained.  Some manufacturers wash as low as 10°C. Again however to maximise the impact then other factors will need to be controlled so that the make time remains similar, e.g. increased starter or increased prime time before renneting.

Next issue we will look at control of other functionality issues such as browning. Note for more information on Mozzarella functionality control refer to Cheese Problems Solved edited by P.L.H. McSweeney