Yeast Types
Cream Yeast:
Liquid or cream yeast is a slurry of yeast cells in water such that 1.5 liters is approximately equivalent to 1kg of compressed yeast.
Delivery to bakeries is by insulated bulk tanker, similar to those delivering milk. The cream yeast is pumped from the tankers into specially constructed tanks designed to keep the slurry constantly agitated and at a temperature of approximately 3c, so that it will retain gassing power for several days.
This form of yeast handling is most suitable for large plant bakeries. The yeast is incorporated into the dough mass by pumping to the dough mixer through a flow meter. When using this type of yeast strict hygienic standards must be adhered to and the system sterilized regularly so the growth of bacteria and wild yeast is prevented.
Cream Yeast Spec Sheet
Compressed Yeast:
Compressed yeast is the most widely used form of yeast in the industrialized countries for both economic and practical reasons. The yeast is sold in compact blocks –usually 1kg- which reduce contact with oxygen in the air.
The packaging reduces gas transfer and controls moisture migration, to provide extended shelf life.
The use of compressed yeast requires no particular precautions. It is easily crumbled into the dough and disperses in cold water without any problems.
Compressed yeast may be slowly frozen (<1°C/min) and retains its initial qualities after being stored for a year at -18°C as long as it is defrosted in positive cold and used within 24 hours.
Compressed Yeast Spec Sheet
Crumble Yeast
Crumble yeast takes the form of relatively fine particles, free flowing, which makes it suitable for either weighing out, or for automatic dosage. It is packed in 15 kg boxes including a loose fitting poly liner.
Crumbled yeast is extremely sensitive to oxygen in the air due to its large surface contact area. Cellular respiration resumes in earnest after extrusion and during packing. This leads to overheating which makes the cooling of the yeast very difficult. The carbon dioxide released, nevertheless, creates an inert atmosphere which stabilizes it.
It is vital that the storage temperature be maintained between 4°C and 6°C. An open carton must be used the same day as overheating rapidly sets in.
Industrial bakers often disperse crumble yeast in water to make a slurry for an automatic dosage.
Crumble Yeast Spec Sheet
Instant Dry Yeast
The fine particles of instant yeast, dried on fluidized bed, are vacuum packed in bags of 125 g, 500 g, 10 kg or more.
Retail sachets- packed under protective atmosphere- are also available in various sizes.
Vacuum packed sachets and bulk are hard, guaranteeing the stability of the product at ambient temperatures. Strict control after packing eliminates any bags which have not retained their vacuum. Partly used bags should be carefully closed and stored at cold temperature in order to maintain the gassing activity of the yeast.
Easy to use
The instant yeast owes its name to the fact that it does not require prior rehydration before being added to the flour. It may be used just as easily as compressed yeast. For most applications the fineness and porosity of the particles allow it to be dissolved quickly and homogeneously into the dough. However, the use of very high speed mixers (mixing time less than 3 minutes) may lead to dispersion problems. In which case, a rehydration stage at 38°C will be required.
Nevertheless, the use of instant yeast means that it is important to avoid direct contact with cold water, ice, or the walls of refrigerated mixers. It is recommended to dry mix the yeast into the flour, or add it onto the dough after the beginning of the mixing process. However, its sensitivity to cold hydration temperature is less pronounced than that of dried yeast.
Its fermenting power is identical to that of compressed yeast for a weight 3 to 4 times less. It means that 1 kg of instant yeast replaces 3 to 4 kg of compressed yeast. The dry matter content of instant yeast being higher (than compressed yeast) it is important to make up the difference in weight with water.
Instant Dry Yeast Spec Sheet
Halal Certificate
Inactive Dry Yeast
Inactive Dried Yeast is a primary grown natural source of protein and B vitamin complex.
It is a yellow to brown powder produced from Baker's Yeast grown by non-alcoholic fermentation on molasses and is inactivated by pasteurisation during drying on steam heated roller dryers.
Inactive Dry Yeast contains glutathione. When inactive dry yeast is mixed into a pastry formulation or bread dough it acts as a reducing agent on the gluten network breaking the sulphydril bonds and making the wheat flour and water mixture more extensible. Mixing times are reduced thus reducing oxidation levels improving and protecting the flavour of the finished product.
Inactive Dry Yeast replaces Sodium Metabisulphite 223 and L Cysteine 920 as a dough or pastry conditioner and requires no international code or ‘E’ number when the raw material is listed on the label.
Inactive Dry Yeast also provides a protein barrier on the outside of baked doughs and pastries and helps support glazes and fillings stopping the finished product from collapsing and going soggy. Baked products such as pizzas, bagels, pretzels, pies and flanges are prevented from distorting and shrinking back.
The Usage Rate is 0.1% to 2 % of flour weight depending on the flour strength and application.
Inactive Dry Yeast Spec Sheet |
