Correctly stored dry beans can remain edible for 25 to 30 years, but will they sprout? The ability to grow a new crop of dry beans from stored beans would substantially increase our self-reliance. We decided to conduct an experiment to see which of our old beans would sprout.

Will old stored dry beans sprout and produce a new crop of beans? The germination rate of dry beans decreases significantly with age and is impacted by storage conditions. Our research study demonstrated that it is possible for 29-year-old beans to sprout, but the germination rate of newer beans is significantly higher.

In this post, we will share the results of our bean sprouting experiment. We took a random sampling of 23 different dry beans. Variables include variety, age, storage conditions, storage container, and sprouting method. The results proved to be quite interesting.

The idea behind this experiment originated from concerns expressed in comments on our YouTube channel. We conducted two research studies using dry beans from our own food storage to determine if old beans would soften up and become edible. You may be interested in reading more about the results of those studies.

Tips for Sprouting Beans and Legumes

Ideally, you will want to select the best quality dry beans that are available. The germination rate will significantly increase with fresh beans.

This is our procedure for sprouting beans and legumes in jars:

Sort beans and remove broken beans or rocks.
Rinse beans well.
Place beans in a jar and cover with water a few inches above the beans. The beans will double or triple in size so leave room for expansion.
Soak for 8 to 12 hours or overnight.
Drain the soaking water and rinse.
Cover beans with a sprouting lid, cheesecloth, or material that will allow for good airflow.
Invert the jar at an angle that will allow for the liquid to drain out and still allow for air movement.
Rinse the beans 2 or 3 times each day until the sprouts are the desired size.

Sprouted beans can be eaten raw in a salad, sautéed, or cooked in a soup. They only last a few days and should be stored in the refrigerator.

Good beans and legumes for sprouting include lentils, chickpeas, white beans, black beans, mung beans, soybeans and adzuki. Pinto beans will sprout, but the success rate tends to be lower.

Kidney, lima, and broad beans must be cooked before eating. It is probably best not to sprout these for eating.

Old Stored Bean Germination Experiment

We designed this experiment with the best variety of dry bean samples available to us. Not all variables could be accounted for, but the results are valuable.

Dry Bean Samples

For this experiment, we collected 23 random samples of dried beans. They range in age from newly purchased to 29-years-old. Samples included black beans, pinto beans, white beans, lentils, kidney beans, lima beans, pink beans, purple beans, and garden green beans.

Storage conditions ranged from the kitchen pantry to a basement storeroom to a bucket in a driveway. Optimal storage conditions for dry beans are in an airtight container in a cool, dry, dark location. Some of our samples met that criteria, others did not come close.

Experimental Design

Each of the bean samples were divided into 3 parts. A small bag containing the original beans was set aside and labeled for reference.

Jar Germination

One portion of each sample was placed in a pint mason jar and covered with a mesh fabric. The beans were rinsed and covered with water. The beans were soaked overnight and drained.

The jars of beans were placed at an angle to allow for good drainage and airflow. They were rinsed twice a day for 4 days.

Ziplock Bag Window Germination

Ten beans of each sample were placed in a labeled Ziplock bag along with a damp paper towel. The bags were taped to the inside of a south facing window and left alone for 4 days.

Results Were Observed and Photo Documentation Created

The samples of the beans were compared, and the results documented. Information was placed on a spreadsheet and the results were carefully evaluated.

Successful Beans Planted

Beans that had demonstrated the ability to germinate were planted in moist potting soil in a warm room under grow lights.

In cases where only a few beans germinated, all of the beans were planted. Ten beans from highly successful samples were planted. A double row of 5 seeds each were planted.

Dry Bean Sprouting Experiment Results

Complete results including photos can be found on this video.

Factors Contributing to Successful Germination

Clear trends emerged as we looked at the data. The following were our general observations:

The age of the bean plays a role in sprouting success. In general (and as we would expect), the older the bean the lower the sprouting success.
Some varieties of dry beans germinated better than others. The black beans seemed to have the best success rate even though one of the samples was quite old.
Storage conditions over time make a significant difference in the viability of the beans. Beans that had been left exposed to significant fluctuations in temperature, stored in a warm environment, or exposed to sunlight had little to no successful germination.
Window sprouting provided better results than jar sprouting in almost every case. This would indicate that the extra light or heat was a factor in germination.

See the summary spreadsheet below for additional details.

Failure to Thrive Post Germination

One interesting thing to note is that several of the beans showed evidence of sprouting but then failed to thrive once planted. Germination alone is not a clear indication of the ability to produce another generation of beans.

Some Old Beans Germinate, Others Do Not

We spent a couple of weeks researching whether old dry beans can be depended on to germinate. I am not confident that the rate of germination of older beans was high enough to produce a survival crop. If you want to have the ability to sprout or plant your dried beans, we recommend taking the following steps.

Rotate your dried beans. Plan to use your stored beans regularly in your normal diet and replace them annually. Good rotation will ensure that you have a fresh supply of dried beans that will sprout when you need them.
Package the dry beans appropriately to extend the quality shelf life.
Store dry beans in a cool, dry, dark location.

Best Storage Conditions for Dry Beans

Dry beans store best in a cool, dry, dark location in air-tight reduced oxygen packaging. You can learn more about how to package dry beans for the longest shelf life in these articles.

How to Use Old Dry Beans

Will old storage beans and legumes germinate? Some will, while others will not. You can eat dry beans that are 25 to 30 years old if they have been stored appropriately. Soak them overnight in water with a little bit of baking soda and use a pressure cooker. You will have success every time.

Another option for old dry beans is to grind them into flour. You can make instant refried beans, use bean flour to thicken soups or sauces, or substitute up to a quarter of the flour in your favorite baked goods.

Just make sure that you use a grinder designed to grind beans and corn or you may damage your grain mill. I really like the NutriMill because it will grind grains, dry beans, and dry corn.

Add dry beans to your diet and store them with your basic food storage. They are a nutritional powerhouse and can be a great asset during challenging times.