Garlic Germination & Storage

Garlic Quality & Storage Notes
 
Garlic can develop internal germination, and garlic with excessive internal germination has no commercial value. The harvest season for garlic in Henan and Shandong provinces is June. At the time of harvest, the germination length of garlic cloves is only 10% of the total clove length. This state can remain unchanged for 3 months, so it is safe to store garlic at room temperature from June to the end of August.
 
After the end of August, garlic must be stored in cold storage warehouses to prevent germination growth.
 
Using reefer containers can prevent moisture damage and sprouting, as reefer containers are typically set to a temperature of -3°C (or 27°F). This is a safe temperature to inhibit the growth of garlic’s internal germination. We also place an independent temperature recorder inside the container to track temperature changes during transit.
 
Garlic’s internal germination will not grow or sprout when temperatures are either above 25°C or below 0°C. If temperatures range between 0°C and 25°C, germination will easily occur. Therefore, if the local temperature in your country is above 25°C, garlic will remain safe for 1 to 45 days after being unloaded from the container—in other words, you will have a 30–45 day shelf life under this temperature condition. Otherwise, the shelf life will be much shorter.
 
Typically, shipping companies like Maersk set the humidity in reefer containers at 65%. Ventilation can be set to "closed" in the middle or late stages of the storage season, as the garlic skins will have already dried out. However, once garlic is unloaded from reefer containers, it must be stacked in a well-ventilated area. Stack the garlic loosely rather than tightly; if possible, use electric fans to blow air over them.
 
Sometimes garlic may become "burnt" (also known as "waxed garlic"). This occurs when garlic is exposed to intense sunlight or stored at excessively low temperatures in cold storage. If a reefer container is continuously powered and maintained at the set temperature and humidity, the garlic will not spoil during transit to the destination.
 
We have many years of experience in shipping high-quality garlic and can assist with garlic storage in your country to prevent germination and burnt garlic.
 
Issues Related to Burnt Garlic
 
A. Burnt Garlic in Summer
 
The quantity of garlic that becomes burnt in summer is very small. The main cause of burnt garlic in summer is extremely high temperatures: when temperatures exceed 36°C, fresh garlic is prone to burning. Burnt garlic can be identified by its green skin. Another cause is poor ventilation when storing large quantities of garlic: if garlic is piled together without proper airflow, the garlic in the middle of the pile may burn. Additionally, covering garlic with plastic film in direct sunlight can cause the top layer of garlic to burn, as temperatures under the film rise sharply. To prevent this, avoid exposing garlic to direct sunlight.
 
B. Burnt Garlic in Cold Storage
 
1. One cause is that garlic was already burnt before being placed in cold storage.
2. We usually start storing garlic in cold storage from the end of June to August 20th. During this period, outdoor temperatures are very high. When large quantities of garlic are placed into cold storage at once, cold storage operators often set the temperature extremely low to speed up cooling. This causes garlic near the refrigeration fans to burn easily. Another factor is inexperience: new cold storage operators may set the temperature too low, and prolonged storage at such low temperatures will lead to widespread garlic burning.
3. To maintain humidity in cold storage, some operators water the floor. Garlic stacked at the bottom may come into contact with this water, leading to burning.
 
C. Color Differences in Burnt Garlic
 
Garlic that was burnt before being placed in cold storage has a dark color, while garlic that burns after being stored in cold storage has a lighter color.
 
It is often difficult to detect burnt garlic, as sometimes only one or a few cloves in a single bulb are affected.
 
Methods to Identify Burnt Garlic
 
1. We must inspect garlic before processing. When entering a cold storage facility, if a strong odor is detected, there is definitely burnt garlic present. In this case, focus inspection on garlic near the fans and at the bottom of the storage area.
2. If garlic feels soft (or if one or more cloves in a bulb are soft), it may be burnt—extra care is needed to check such garlic.
3. Hold the garlic and smell it: a strong, unusual odor confirms it is burnt. This is the most effective method for detecting burnt garlic.
 
Note: Thorough inspection—by checking, touching, and smelling more garlic—is essential to identify burnt garlic.
 
Reefer-shipped garlic is typically transported from mid-September to the end of the following May, a period of nearly 8 months. However, reefer-shipped garlic is prone to various quality issues, so inspection is crucial. The most challenging part is distinguishing between burnt garlic and germinated garlic.
 
Causes of Germinated Garlic
 
1. If reefer garlic is left outside cold storage for an extended period, it will start to sprout.

2. Poor temperature control by cold storage operators can cause garlic to sprout inside the cold storage.

3. Storing garlic in cold storage too late (e.g., after August 20th) can lead to sprouting, as temperatures begin to drop during this time.
 
Before packing reefer garlic, the garlic must be carefully inspected inside the cold storage.
 
Key Notes After Removing High-Quality Garlic from Cold Storage
 
1. October to December: Temperatures remain relatively high during this period. When reefer garlic is taken out of cold storage, its skin will be covered in condensation, making the garlic prone to cracking. Do not leave it outside for long—sort and transport it immediately. For pre-packaged garlic (which takes longer to pack), return partially packed batches to cold storage temporarily after each packing session. At this stage, garlic has only recently been stored in cold storage, so it is less likely to sprout.

2. January to March: Temperatures are very low. Reefer garlic can be left outside cold storage for 5–8 days without sprouting, but care must be taken to prevent frostbite.

3. April to late May: This is the riskiest period for packing reefer garlic. After long-term storage, most quality issues (e.g., sprouting, burning) are likely to occur. Reefer garlic can only be left outside cold storage for 24 hours; ideally, packing and transport should be completed in one day. For small-pack garlic, return unused portions to cold storage, but ensure cartons are not stacked tightly together. The storage temperature for cartoned garlic must be lower than that for bagged garlic—tight stacking will cause garlic in the middle and bottom of the pile to sprout easily. Therefore, garlic must be carefully inspected before loading into containers.