1. Scope of Application:

All fermented products used in bread-making industries.

2. Responsible Personnel:

Experienced master craftsmen in the bread-making industry.

3. Usage Instructions:

The amount of yeast used in various types of bread depends on environmental temperature, raw materials, equipment, and process duration. Generally:

• Fancy breads: 1.5% to 1.8% of the flour weight.
• Flatbreads: 0.5% to 1% of the flour weight.
• Semi-leavened breads (e.g., Taftoon and Sangak): Around 1.5%.

In hot seasons and regions, the quantity should be reduced, while in colder seasons or when using stronger flours, it can exceed the minimum level stated. Additionally, when the process time is limited, the usage can be increased up to 2%, depending on the type of industry. For sweet breads containing higher amounts of sugar and oil, yeast usage of up to 2.5% of the flour weight is recommended.

4. Storage Conditions:

Yeast is a biological organism requiring specific conditions for optimal performance. Proper storage temperature directly affects its shelf life and activity:

• Dry yeast: 8-12°C (refrigerator temperature); temperatures below 25°C are also acceptable.
• Fresh yeast: 0-4°C.

Key Storage Tips:

• Once opened, the package must be tightly sealed and stored in the refrigerator.
• Storing yeast in warm or open environments leads to a significant decline in activity and a reduction in live cell count.
• Yeast transportation must be done under appropriate temperature conditions.

Shelf life at various temperatures:

• Below 12°C: 24 months.
• 13°C to 24°C: 18 months.
• 25°C to 32°C: 6 months.
• Above 32°C: Less than one month.

Vacuum packaging provides a longer shelf life compared to regular bags, but in both cases, storage in a cool, dry place is essential.

5. Usage Instructions:

1. Mix flour and yeast (or sugar for sweet and fancy breads) in their dry form until uniformly blended.
2. After 3-4 minutes, when the yeast begins to activate, add the water and salt solution (or oil for fancy breads).
3. Once the mixing process is complete and the dough structure is formed, allow the dough to rest for an initial fermentation period of at least 15 minutes.

Important Tips:

• Insufficient dough resting reduces the bread’s quality in terms of aroma, texture, volume, and shelf life.
• Suitable flour:

• • For leavened breads: Flour with 19-22% bran extraction.
  • For flatbreads: Flour with 15-21% bran extraction.

• For strong flours: Use more warm water, faster mixing speeds, longer mixing times, less salt, more yeast, and longer resting times.
• For weak flours: Increase salt, aerate the flour, mix with stronger flour, add previous dough, reduce resting time, and include additives like vitamin C (3 tablets per sack), dried milk, gluten (up to 2%), and appropriate improvers for the product type.
• Water and raw material temperature: Should be maintained below 25°C. The final dough temperature should be 27°C, and mixing speeds should be adjusted to prevent yeast overheating.
• Initial dough preparation: Start with dough that does not contain salt and oil. After 3-4 minutes of mixing, add the saltwater or oil solution.
• Critical Note: The looser the dough, the better the yeast will perform.