This Wiki Article discussed Non-Far Dry Milk. It is divided into the following sections:
- NDM Use In Cheese Making
- NDM Manufacture
- NDM Classification
- NDM Storage
- NDM Handling
- NDM Addition To Milk
Milk is commonly dried into a powder form to:
- Preserve it as milk powder has a significantly longer shelf life than liquid milk and as milk powder does not need to be refrigerated due to its low moisture content.
- Reduce its bulk for economy of transportation.
- Use it as an additive in food making such as cheese.
Common powdered milk and dairy products are:
- Non-Fat Dry Milk
- Dry Whole Milk
- Dry Buttermilk
- Dry Whey Products
- Dry Dairy Blends
Non-Fat Dry Milk (NDM) is the most common, it’s milk sources in decreasing manufacture are:
- Cow’s Milk
- Goat’s Milk
- Sheep’s Milk
NDM & No Milk
Cheese is rarely made using NDM and no liquid milk. This is primarily because the protein is denatured (changed from its natural state), and thus it is really only useful for making yogurt and soft cheese. While feasible for making other cheeses, the quality of the curd and resultant cheese are very different, for example the cheese will not melt.
NDM & Hobby/Artisan Cheese Making
In hobby and artisanal cheese making, adding NDM is rare, except in yogurt making to result in a thicker consistency.
NDM & Industrial Cheese Manufacture
Conversely, in industrial cheese making, NDM is often added to milk to help standardize the milk before making cheese where it is called “Cheese Milk Extension”. There are several reasons NDM is added:
- Maintain consistent composition of cheese.
- Produce more pounds of cheese per pound of fat purchased.
- Increase the output per vat and daily plant production.
- Enable more efficient production of reduced fat cheeses.
- Enable the storage of non-fat milk solids from peak production periods for use during periods of low milk production.
However, using NDM in cheese making also alters the cheese body, texture, flavor, and keeping quality.
Most varieties of cheese can tolerate up to 2% solids added NDM in the cheese milk without experiencing problems in body or texture. Levels of addition above 2% NDM may lead to crumbly body and poor texture in the cheese.
Cottage cheese is often made by fortifying skim milk with up to 4% added low-heat NDM. For the best quality curd, it has been found that milk for medium and large size curd should be 10% to 12% solids, whereas milk for small curd size should contain 9.5% to 11% solids.
NDM should not be used in cheeses that are dependent on eye-formation, e.g., Swiss, Gouda, etc as the NDM may cause weak spots in the curd which would result in poor eye formation.
Historically, NDM was produced by vacuum evaporation of skim milk and then spray-drying the skim milk concentrate. Current powder plants use a centrifugal dryer.
Grades of NDM (extra, standard, and instant) are based on specifications for fat, moisture, titratable acidity, and solubility indices.
NDM is also classified on the basis of the heat treatments it receives during manufacture, for example low heat NDM is manufactured with a minimum pasteurization treatment and limited heating during concentration and spray-drying.
Quality of NDM is critical, NDM processed with higher heat treatments:
- Produces curd with a weaker body.
- Causes delays in rennet action.
- Produced some defects in cheese flavor and body.
Thus NDM processed with lower heat is preferred.
Retail NDM is often “instant” grade with no information on heat treating.
To maintain the best flavor and functional properties in NDM for cheese making, NDM should not be stored more than nine months. Most retail packages have a “best by” date.
NDM dust should be prevented because if wetted, it provides an opportunity for the growth of undesirable microorganisms.
If milk is being pasteurized, NDM should be added to the cheese-milk prior to pasteurization so that the full pasteurization of the standardized cheese-milk can provide for protection against pathogenic bacteria.
If adding directly to the milk, ensure that all lumps of NDM have been properly dispersed or strained.
For reduced-fat and part-skim milk based cheeses, it is recommended that:
- The NDM be reconstituted with warm water as a concentrate prior to addition to the milk.
- The reconstituted NDM be allowed to properly hydrate several hours prior to cheese making to ensure that proteins are fully hydrated and functional in the cheese making process.