The finished cheese is too dry or hard.

Possible cause
Not enough rennet was added.
Solution
Add more rennet.

Possible cause
The curd was cut too finely.
Solution
Cut the curd into larger cubes.

Possible cause
The curd was heated to too high a temperature.
Solution
Reduce the temperature.

Possible cause
The curd was stirred too vigorously.
Solution
Handle the curd gently.

Acidity during cheesemaking is not high enough.

Possible cause
The starter culture is not working.
Solution
The milk contains antibiotics. Do not use milk from animals receiving any medication for cheesemaking.

Possible cause
The starter culture is contaminated.
Solution
Use a new starter.

Possible cause
Cleaning product residues, especially chlorine, remain on the equipment.
Solution
Wash all equipment thoroughly.

The milk does not coagulate or form a firm curd.

Possible cause
Too little rennet was used.
Solution
Increase the amount of rennet.

Possible cause
Poor-quality rennet was used.
Solution
Use high-quality rennet and store it correctly.

Possible cause
The rennet was deactivated by dilution in water that was too warm.
Solution
Dissolve the rennet in cool water.

Possible cause
The rennet was mixed in the same vessel as the cheese colouring.
Solution
Make sure the rennet does not mix with the colouring.

Possible cause
The thermometer is inaccurate and the milk was too cold.
Solution
Check the thermometer in boiling water: it should read exactly 100°C.

Possible cause
The milk contains colostrum.
Solution
Do not use milk containing colostrum.

After adding rennet, the milk coagulates too quickly during stirring, forming very small curd grains.

Possible cause
The milk is too acidic.
Solution
Coagulation should not occur earlier than 5 minutes after adding rennet. Reduce acidity.

The cheese is difficult to remove from the mould after pressing.

Possible cause
Coliform bacteria and/or fungi developed in the milk and produced gas, causing the cheese to swell during pressing and become difficult to remove.
Solution
Observe strict hygiene. Sterilise equipment in boiling water or a sterilising solution. Use only clean, cold milk for cheesemaking. Pasteurise raw milk.

The cheesecloth is difficult to remove after pressing, and pieces of cheese come away with it.

Possible cause
The cheese is contaminated with coliform bacteria and/or yeasts.
Solution
Observe strict hygiene.

Possible cause
The cheese was not rewrapped in fresh cloth when necessary. This is a common problem with cheeses made using thermophilic cultures.
Solution
Rewrap the cheese as directed in the recipe.

The cut cheese contains small holes and looks like a sponge.

Possible cause
The cheese is contaminated with coliform bacteria and/or yeasts. This may be noticed during heating: the curd has an unusual colour and resembles bread dough.
Solution
Observe strict hygiene.

During maturation, damp patches appear under the paraffin and begin to rot.

Possible cause
The cheese was not turned often enough.
Solution
At the start of maturation, turn the cheese at least once a day.

Possible cause
The cheese contains too much moisture.
Solution
Take steps to reduce moisture content.

Mould develops on the cheese surface during drying or after paraffin-coating.

Possible cause
The maturing room is too humid and/or essential hygiene rules were not followed.
Solution
Thoroughly wash the shelves where the cheeses rest. Reduce room humidity.

Acidity is too high during cheesemaking.

Possible cause
The milk was stored incorrectly before cheesemaking or pasteurisation.
Solution
Immediately chill freshly milked milk below 1.5°C. Store it at this temperature or lower until cheesemaking begins.

Possible cause
Too much starter was added.
Solution
Reduce the amount of starter.

Possible cause
Acidification lasted too long.
Solution
Shorten acidification and add rennet earlier.

Possible cause
The cheese is too moist.
Solution
Take steps to reduce the cheese’s moisture content.

The cheese surface becomes oily during drying.

Possible cause
The cheese is drying at too high a temperature.
Solution
Move the cheese to a cool room. The temperature should not exceed 18°C.

Possible cause
The curd was stirred too vigorously.
Solution
Handle the curd more gently.

Possible cause
The curd was heated to too high a temperature.
Solution
Lower the heating temperature.

The cheese has no flavour or its flavour is too weak.

Possible cause
Maturation was too short.
Solution
Leave the cheese to mature for the time specified in the recipe or longer.

Possible cause
Acidity was not high enough.
Solution
Increase acidity during cheesemaking.

The cheese is too moist.

Possible cause
Acidification did not proceed correctly during cheesemaking.
Solution
Increase acidity during cheesemaking.

Possible cause
The milk has too much fat.
Solution
Milk fat content should not exceed 4.5%. If it is higher and excessive moisture occurs, remove some cream before cheesemaking.

Possible cause
The curd was heated too quickly. A sudden temperature rise forms a membrane around the grains, preventing moisture from draining.
Solution
Raise the temperature gradually: no more than 0.5°C every 5 minutes.

Possible cause
Too much whey remained in the curd.
Solution
Cut the curd into smaller pieces.

Possible cause
The curd was heated at too low a temperature.
Solution
Raise the heating temperature.

The cheese tastes bitter.

Possible cause
Hygiene was inadequate during milk processing or equipment preparation.
Solution
Keep the milk cool before processing. Equipment must be sterile and free from milk deposits, which build up on surfaces in prolonged contact with milk and can be removed with a cleaner for items exposed to lactic acid. Sterilise all equipment before making cheese from raw milk.

Possible cause
Too much rennet was used.
Solution
Reduce the amount of rennet.

Possible cause
Acidity was too high during cheesemaking.
Solution
Take steps to reduce acidity.

Possible cause
Too little salt was added after crumbling the curd.
Solution
Increase the amount of salt added to the curd.

The cheese tastes much too sour.

Possible cause
The cheese contains too much water.
Solution
Reduce moisture during cheesemaking.

Possible cause
Acidity was too high during cheesemaking.
Solution
Reduce acid development.