Products for cheesemaking
.Starters
Mould Spores
Lipase
Calcium Solution
Cheese Wax
Thermometer
Cheese
Cloth
Rennet
The following information was extracted from the book "HOME
CHEESEMAKING" by Neil and Carole Willman
Starters:
What is a starter?
A starter is not rennet or junket but a specially selected bacteria.
Starters are chosen because they possess certain characteristics which
are of value to cheesemaking. These characteristics can include such things
as acid production, enzyme production, flavour component production or
gas production (carbon dioxide). Some starters have one of these characteristics,
while others have more than one. Starters are very tiny. In one millilitre
of liquid starter there are about 200,000,000 (two hundred million) living
starter organisms.
Why do we use starters?
Starters are mainly used for acid production. Many years ago naturally
occurring bacteria in the milk were used, however their numbers are inconsistent
and many of the bacteria in raw milk are spoilage organisms. The quality
of cheeses made from raw milk will be quite variable. Pasteurisation kills
many of the desirable bacteria in raw milk and hence the need to add starters
to replace them. Acid production is necessary in the making of cheese,
as the acid helps the curd to form and shrink, as well as preventing the
growth of spoilage bacteria and determining the characteristics of the
cheese.
Mould Spores:
Mould spores are sometimes used in the manufacture of cheese. These
are available in two categories; Blue mould spores (Penicillium roqueforti)
and White mould spores (Penicillium candidum). Blue mould spores are used
for making Blue Vein, Roquefort, Stilton and Gorgonzola cheeses. White
mould spores are used for making Camembert and Brie.
Others Other organisms can be used in the making of other cheese types.
These include a bacteria (Propionibacterium shermanii) added to the milk
to provide extra gas production to form the eyes in Swiss cheese, and a
bacterial culture used for rubbing on the surface of cheeses such as Tilsit
and Havarti(Brevibacterium linens).
Lipase:
Lipase is an enzyme (protein material) which has the function of breaking
down the fats of the milk or cheese. Cheeses which use lipase during their
manufacture are Fetta, Romano, Pecorino, Parmesan, and many others.
Calcium
Solution:
Calcium chloride solution is used to assist cheesemakers when milk
is calcium deficient. It assists the milk coagulation process for rennet
set cheeses.
Cheese Wax:
Cheesewax provides a suitable moisture barrier on the cheese to prevent
rapid drying. They are a mixture of microcrystalline wax and parrafin.
Hard cheeses that are going to be stored for more than one month will dry
out and crack if not protected. They may also become mouldy and inedible.
These cheeses may be waxed before maturing to prevent them from drying
out. The waxing will be more successful if you apply a plastic cheese coating
to the cheese first. This gives the wax a fat free and moisture free surface
on which to adhere. Better results are obtained when a plastic cheese coating
is applied first.
Plastic
Cheese Coating:
The plastic coating is a PVA emulsion specially designed for use on
cheese. Two coats of plastic cheese coating are normally applied by brushing
with a small paint brush, or rubbing the coating on with a coarse sponge.
Thermometer:
It is important to have a good accurate thermometer for cheese and
yoghurt making. A thermometer with a scale of -10 to 110°C with graduations
at 1°C intervals is usually satisfactory
Cheese
Cloth:
The cheese cloth is also known as cheese bandage. It is applied to
rinded cheese to assist in the development of a good rind. The cloth stays
on the cheese during storage.
Rennet:
Rennet may be from animal or vegetative sources. Traditionally calf
rennet was used, but vegetative alternatives are now common. Vegetative
rennets are made from fungal origin with Mucor mehei being the most commonly
used.
Genetic engineering techniques some 'vegetarian' cheeses made using
chymosin by genetically engineered microorganisms. The genetic material
(DNA) which enables chymosin replication is placed into a microorganism
which is then cultured producing chymosin. This chymosin is identical to
that found in calf rennet. The organisms used to produce GE Chymosin are
either a yeast, Kluyveromyces lactis, or a bacteria Escherichia coli.
Rennet is an enzyme which reacts with the protein in the milk to coagulate
the milk. It is therefore added to the milk to turn it from the liquid
state to a solid state. The active enzyme in calf rennet is known as Chymosin.
When using rennet always dilute it in 10 times its volume of cool boiled
water. If you don't do this you will find that your rennet has started
working before you have mixed it in properly, giving a very uneven curd.
Be sure that the water you are using is not hot or it will adversely affect
the activity of you rennet. Do not sanitise rennet measuring utensils with
sodium hypochlorite. Sodium hypochlorite will adversely affect the activity
of your rennet. You will need to rinse these utensils with boiling water.
Hard cheeses cannot be made without rennet. Hard cheeses claiming to
be rennet free are more correctly 'animal rennet' free. These cheeses are
made from microbially produced chymosin, which is classed as fermented
or vegetarian rennet.
The above information was extracted from the book "HOME
CHEESEMAKING" by Neil and Carole WillmanBack to top
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Cheese and Rennet
an Information Sheet from the Vegetarian Society (UK)
What is Cheese? What is Rennet?
Cheese is made by coagulating milk to give curds which are then separated
from the liquid, whey, after which they can be processed and matured to
produce a wide variety of cheeses. Milk is coagulated by the addition of
rennet. The active ingredient of rennet is the enzyme, chymosin (also known
as rennin). The usual source of rennet is the stomach of slaughtered newly-born
calves. Vegetarian cheeses are manufactured using rennet from either fungal
or bacterial sources. Advances in genetic engineering processes means they
may now also be made using chymosin produced by genetically altered microorganisms.
Cheese Manufacturing Process
The exact processes in the making of cheese varies between different varieties.
However, all cheeses are made by essentially the same method. Initially,
the milk is usually pasteurised by heating at 72 degrees C for 15 seconds
to destroy potentially harmful bacteria. The milk is then cooled to around
30 degrees C and a starter culture of lactic acid bacteria is added to
help souring. These convert lactose into lactic acid and help in the coagulation
process. In addition, they also have a beneficial effect on the eventual
quality, taste and consistency of the cheese. Some cheeses are coagulated
entirely by lactic acid bacteria and are known as lactic curd or acid-curd
cheeses. However, some cheeses sold as lactic-curd cheese may have had
rennet added.
The next stage is the addition of rennet, containing the enzyme chymosin.
Rennet is usually sourced from the abomasum (fourth stomach) of newly-born
calves. Here, chymosin aids the digestion and absorption of milk. Adult
cows do not have this enzyme. Chymosin is extracted by washing and drying
the stomach lining, which is then cut into small pieces and macerated in
a solution of boric acid or brine at 30 degrees C for 4-5 days. Pepsin
may sometimes be used instead of chymosin. This is usually derived from
the abomasum of grown calves or heifers, or less commonly pigs. Pepsin
may be mixed with calf rennin. Rennet coagulates the milk, separating it
into curds and whey. This is called curdling. Chymosin breaks down the
milk protein casein to paracasein which combines with calcium to form calcium
paracaseinate, which separates out. Milk fat and some water also becomes
incorporated into this mass, forming curds. The remaining liquid is the
whey. The strength of different rennets can vary, though usual strength
varies between 1:10 000 and 1:15 000 ie one part rennin can coagulate 10
- 15 000 parts milk.
Other substances may also be added during the cheese making process.
Calcium chloride is added to improve the curdling process, and potassium
nitrate is added to inhibit contaminating bacteria. Dyes (eg annatto, carotene),
Penicillium roquefortii mould spores to promote blue veining, or propionic
acid bacteria to encourage hole formation may be added.
Following curdling, the curds are cut and drained. The size of the cut
and the methods used vary for different cheese varieties. For soft cheeses,
the curds are sparingly cut and allowed to drain naturally. For hard cheeses,
the curds are heated and more whey is drained off. The curds are then cut
into small pieces, placed in vats and pressed.
After pressing, the curds may be treated in a number of ways. They may
be moulded into different shapes, soaked in a saltwater solution, be sprayed
with mould forming spores or bacteria, washed in alcohol, or covered in
herbs.
The final stage is ripening, or maturation. This can vary in length
from 4 weeks to 2-3 years, depending on the type of cheese. During ripening
flavours develop, the cheese becomes firmer and drier, and special characteristics
such as holes, blue veining and crust formation occurs.
Vegetarian Cheeses
Vegetarian cheeses are made with rennets of non-animal origin In the past,
fig leaves, melon, wild thistle and safflower have all supplied plant rennets
for cheese making. However, most widely available vegetarian cheeses are
made using rennet produced by fermentation of the fungus Mucor miehei.
Vegetarian cheese may also be made using a rennet from the bacteria Bacillus
subtilis or Bacillus prodigiosum.
Advances in genetic engineering techniques mean that some 'vegetarian'
cheeses may now be made using chymosin produced by genetically engineered
microorganisms. The genetic material (DNA) which encodes for chymosin is
introduced into a microorganism which can then be cultured to produce commercial
quantities of chymosin. This is done by extracting genetic material from
calf stomach cells which acts as a template for producing the chymosin
encoding DNA. This can then be introduced into the microorganism. Once
the genetic material is introduced there is no further need for calf cells.
Alternatively, the chymosin encoding DNA can be biosynthesised in the laboratory
without the use of calf cells.
The chymosin produced is identical to that produced by calf stomach
cells. The development of genetically engineered chymosin has been encouraged
by shortages and fluctuations in cost of rennet from calves. It's manufacturers
claim that genetically engineered chymosin will end the cheese making industry's
reliance on the slaughter of calves.
Chymosin encoding DNA has been introduced into three different microorganisms.
These are the yeast Kluyveromyces lactis, the fungus Aspergillus niger
var awamori, and a strain of the bacteria Escherichia coli. All of these
have now been approved and cleared for use by the Ministry of Agriculture,
Fisheries & Food (UK). There is no legal requirement for manufacturers
to state whether a genetically engineered rennet has been used in the cheese
making process.
Vegetarian cheeses are widely available in supermarkets and health food
stores. A wide variety of cheeses are now made with nonanimal rennet and
labelled as suitable for vegetarians. No particular type of cheese is exclusively
vegetarian. Soft cheeses are as likely to be non-vegetarian as hard cheeses.
A list of cheeses suitable for vegetarians is available from The Vegetarian
Society.
Types of Cheese
The type of cheese produced depends on the milk used and the cheese making
process. The milk used may be full fat, semi-skimmed or fully skimmed,
this affecting the fat content of the cheese. It may be pasteurised or
unpasteurised. Milk from different animals and different breeds is important
in determining the final flavour. As well as cow's milk, cheese may be
made from sheep or goat's milk.
Soft cheeses may be fresh or ripened. Fresh cheeses include quark, cottage
cheese and cream cheese. Ripened soft cheeses include Brie and Camembert.
Semi-soft cheeses include Stilton, Wensleydale and Gorgonzola. Hard cheeses
include Cheddar, Cheshire, and Gruyere. Parmesan is a strongly pressed,
very hard, dry cheese ripened for 2 - 3 years and then grated. Whey cheeses
such as Ricotta are made as a by-product of other cheeses from the whey
removed during pressing. Processed cheeses are either made with trimmings
that are left over from the manufacture of other cheeses, or from dried
milk powder. Flavourings, colourings and other additives are used.
Nutritional Aspects
Cheese is a good source of protein, calcium, zinc, and vitamin B12. However,
full fat cheese is a major source of saturated fat which can lead to raised
serum cholesterol levels. Also, it contains no carbohydrate or fibre, and
is a very poor source of iron. Vegetarians, particularly new vegetarians,
should be wary of too high a consumption of cheese.
This article is copyright to the Vegetarian Society (UK), but may be
freely copied provided it is kept intact, not altered and these lines are
included.
Originally posted in the Usenet newsgroup rec.food.veg by John Davis.
Converted to HTML by: Donald Graft
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