Spouting or Greening Potatoes . . . Keep or Toss?

“Should a potato with sprouts be used or tossed?” There is a great deal of conflicting advice on the question of use or toss. It comes down to the condition of the potato.

Sprouted potatoes in bag
Photo: MGeiger

As the warmer months approach, potatoes in storage may be showing signs of sprouting or even vigorously sprouting; shriveling may also accompany sprouting as the starch in the potato is converted to sugar to feed the new plants. Potatoes have an inherent natural dormancy maintained by endemic plant hormones. The concentration of the hormones in the tubers decreases over time resulting in sprouts forming at the eyes. When sprouting starts to occurs, this is a sign that the dormant period is over and nature is telling them it is time to reproduce. Even under ideal well ventilated, cool, dry, and dark storage conditions, this natural phenomenon occurs. Potatoes that are improperly stored in the home may exhibit the same sprouting and shriveling regardless of time of year as conditions may trick them into “thinking spring.”

Why the Concern?

Potatoes contain two kinds of glycoalkaloids called solanine and chaconine. Both are naturally occurring chemical compounds. Glycoalkaloids are found throughout potato tubers, but are in highest concentration in the leaves, flowers, sprouts, green skin and the area around the potato ‘eyes’. The lowest concentration is found in the flesh of the tuber.

In normal tubers, glycoalkaloids concentrations are small with a slightly higher concentration in a thin layer immediately under the skin and around the eyes. Peeling potatoes and removing the eyes reduces the presence of the compound. The concentration of glycoalkaloids in sprouts is much higher and can be high enough to be toxic to humans. The more potatoes sprout, the greater the presence of glycoalkaloids in both the sprout and potato itself. High concentrations of glycoalkaloid compounds give potatoes an unpleasant, bitter taste and can lead to headaches, vomiting and other digestive issues.

According to articles by Michigan State and North Carolina Extensions, removing the sprouts will allow safe consumption of the rest of the potato as long as the potatoes are firm, not soft or shriveled, and the sprouts are small. Further, most of the nutrients are still intact. But if the sprouts are long (1 inch or more) and the potato has shriveled, it should be tossed.

The same is nearly true for potatoes exhibiting greening. Green skinned potatoes have been exposed to too much light. Light causes the potato to produce chlorophyll and activate the skin cells to produce solanine which has a bitter taste and is an irritant to the digestive system. Because of the bitter taste, most people do not eat enough to get sick. Despite that, always use caution when greening is found on the tubers as this indicates elevated levels of solanine. Peeling the potato and removing the green portions by simply cutting them out will eliminate most of the toxin. However, if more extensive greening occurs into the tuber, throw the tuber away. Never eat tubers that are green beneath the skin. 

Cooking does not destroy glycoalkaloid compounds; therefore, potatoes exhibiting sprouts and shriveling or deep green parts should not used. Potatoes that are firm and exhibiting only small sprouts at the eye and/or skin-deep greening can be eaten if the entire sprout and any green-tinged parts of the potato are cut away.

Storing Potatoes to Prevent Sprouting and Greening

Storing potatoes the right way will prevent sprouting and greening. As mentioned earlier, potatoes should be stored in a cool (45-50 degrees), dark, dry, and well ventilated location for maximum freshness.  Kept in these conditions, potatoes will likely last up to three months or longer. At room temperature, potatoes will usually last about 2 weeks. Storing potatoes in a cellar or cool basement is ideal. Storage areas should always be away from appliances that give off heat or any area that allows light. If potato tubers will be consumed soon, they can be stored in a cupboard/pantry in a paper bag.

Don’t store potatoes in the fridge. Cold temperatures turn the starches in potatoes into sugars. This makes potatoes sweeter and cook dark. Also, potatoes should not be stored with onions. Storing them together shortens their shelf life. Onions produce ethylene gas which causes potatoes to spoil prematurely. The high moisture content of potatoes can cause onions to turn brown and rot.

In conclusion, sprouted or green potatoes are not necessarily destined for the landfill or compost pile.  With certain precautions, the potato may be safe to eat as long as sprouts and green spots can be cut away. If there is extensive sprout growth, shriveling, and deep green within the tuber, potatoes should be tossed to prevent risk of potential toxicity from solanine and chaconine, the two natural glycoalkaloid compounds found in potatoes.

For other questions about food safety and storage advice that will help keep food safe after purchase or harvest, The Food Keeper is an excellent resource. This handy reference tool was produced by the Food Marketing Institute at Cornell University in conjunction with the United States Department of Agriculture (USDA). It contains useful guidelines for storing food safely. The app is just a finger touch away for IOS and Android smartphones users by visiting the App Store or Google Play and searching for “FoodKeeper Mobile App.” The same app is also available for computer or pads at FoodSafety.gov.

Sources:
Toxic Glycoalkaloids in Potatoes, Centre for Food Safety
Glycoalkaloids in Potato Tubers, Oregon State University Extension
Food Safety of Potatoes, Michigan State University Extension 
Is It Safe to Eat a Potato That Has Sprouted?, North Carolina Extension
Is It Safe to Eat Sprouted Potatoes? Here’s What the Experts Say, EatingWell
Are Sprouted Potatoes Safe to Eat?, Poison Control

Reviewed and updated 3-2024, mg.

Marlene Geiger

I am a graduate of the University of Nebraska-Lincoln with a BS in Home Economics Education and Extension and from Colorado State University with a MS in Textiles and Clothing. I enjoy spending time with family and friends, gardening, quilting, cooking, sewing, and sharing knowledge and experience with others.

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What’s Under Your Kitchen Sink?

Is your ‘stash it’ place the cabinet under your kitchen sink? Too often it ends up being the place that this-that-and-the-other gets stuffed for lack of a better location or simply to get it out of sight. When this happens, it’s hard to keep this area tidy and ready for the unexpected leak.

Clutter under the kitchen sink
Under-the-sink poorly managed storage. Photo: Robin Litchfield

Along with the maze of pipes that live under the kitchen sink, it’s always amazing what may be found in the ‘cave of castoffs’ scattered among the needed and regularly used dishwashing and kitchen cleaning supplies.

The best way to reorganize and reclaim this space is to take everything out. Once the cabinet is emptied, clean the cabinet to remove dust and crumbs. This is also a good time to note any water stains on the cabinet floor or suspicious signs with any of the pipes, water lines, or faucets inside the cabinet.  (Anything suspicious should be checked out to prevent a plumbing disaster.)

Before putting anything back in the cabinet, consider an absorbent mat for the bottom of the cabinet to absorb a bit of water from a dripping sponge or leaking from a pipe or a stored product. These mats protect the cabinetry and prevent the formation of mold. One may also want to consider purchasing clear plastic containers for organizing or protecting items or even installing tiered under-sink organizers to make use of the available vertical space or pull-out racks to keep items from getting lost in the back of the cabinet and bring them forward for easy access. Home improvement and container stores have any number of these items designed to work around the pipes and garbage disposal. The inside of the cabinet doors are an ideal place to mount a towel rack or racks made for storing everything from trash bags to paper towels and sponges.

With a clean and open space, let’s get started on reclaiming that space and make it work better for you using Store This, Not That tips from various organization experts. It starts with an inventory of the contents noting what should be in the cabinet, what should or could be stored elsewhere, and what should be discarded.

NOT THAT
(What not to store under the kitchen sink.)

Cleaning items. Unused, old, broken or no-long suitable cleaners, sponges, scrub brushes and other castoffs that have accumulated behind closed doors should be discarded. If they might have a life in another capacity, place them with the anticipated activity. If you like to keep worn nylon scrubbers and brushes around to wash garden produce or other outdoor items, move these items to the space where they would likely be used for this purpose.

Overstock, refills, or extra supplies. Quantity or bought-ahead, unopened products should go to another storage area. Perhaps a space in the basement or a storage closet is a great place to store bulk paper towels, dishwasher tablets, boxes of trash bags, and other like items. If you need a reminder of what is on hand, leave yourself sticky notes inside of the cabinet. Refill from the stash in the alternative space until the quantity is exhausted; add the item to your shopping list and repurchase.

Towels, rags, paper towels, paper bags. All of these items absorb water and odors. While absorbing water in the event of a leak may be a good thing, it will ruin them. These items are also prone to odor absorption from other stored items or the waste basket when combined with heat and humidity coming from the sink and/or dishwasher. If the only storage space available for these items is under the sink, they should be stored in closed plastic containers.

Metal items. With one exception*, tools, pots and pans, metal cookware, or anything else that is prone to rusting does not belong. This also includes small appliances and light bulbs. (*Exception will be discussed in Save This.)

Produce, food items, pet food/treats. Produce and dry foods may mold under the sink. 

Harsh chemicals, flammable products, insecticides. Bleach, insecticides, solvents, thinners, paints, polishes, and household cleaners have no place under the kitchen sink. These items need to be stored in the basement, garage, or utility area and away from small children. Occasionally the containers of these items spring a leak or emit fumes—all of which we do not want in our living areas and especially not in our kitchen. Further, often a dishwasher sits next to the sink cabinet; heat or an electrical spark and flammable fumes could cause a sudden explosion or fire.

STORE THIS
(What to store under the kitchen sink.)

Cleaning products. Keep the essentials such as vinegar, dish soap, dishwasher products, cleansers, scrubbers, sponges, brushes, kitchen gloves, and cleansing agents—all of the items needed daily to maintain a clean and healthy kitchen. (If young children are in the home, the doors to the cabinet should be secured with child-proof locks to prevent accidental poisoning from any of these products.) A pull-out rack or a lazy susan is a great way to corral these items and make them easy to access.

Small fire extinguisher. One should always have a serviceable fire extinguisher in the kitchen in the event of a grease fire. Under the sink within quick and easy reach is one of the best locations for it. Before storing, the viability date should be checked and replaced if out of date. Consider mounting the extinguisher to a side wall of the cabinet.

Garbage disposal tool*. The one and only tool that should be stored under the sink is the garbage disposal tool used for unjamming the garbage disposal. Inevitably this tool gets lost. Some disposals come with a pocket for storing the tool on the side of the disposal. If not, consider placing the tool in a ziplock bag and thumb tacking the bag to a cabinet wall making it easy to see and locate when a jam occurs.

Miscellaneous. Depending upon space, items such as a vase or two, trash bags, dish towels in plastic containers, small dust pan and brush, and bags for recycling (contained in some manner) may find a home under the sink.

By reclaiming and organizing under sink space, the kitchen is safer and more efficient. Maybe the space under other sinks in the home need a look, too?

Updated December 2023, mg.

Marlene Geiger

I am a graduate of the University of Nebraska-Lincoln with a BS in Home Economics Education and Extension and from Colorado State University with a MS in Textiles and Clothing. I enjoy spending time with family and friends, gardening, quilting, cooking, sewing, and sharing knowledge and experience with others.

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Chocolate – Shelf Life, Storage, and Bloom

Does chocolate go bad? That is a question with a long answer. The type, quality, and storage conditions of chocolate affect its shelf life. Let’s dig in and learn more about chocolate.

Chocolate bar and cocoa
Pieces of chocolate and cocoa powder – Photo: Canva.com

SHELF LIFE

The shelf life of a food product is the period of time during which it will retain acceptable appearance, aroma, flavor and texture. Chocolate comes in various forms—cocoa, unsweetened, dark, semi-sweet, milk, ruby, white. Because each type of chocolate contains varying amounts of chocolate solids, cocoa butter and additives, the shelf life varies. 

Chocolate is derived from the chocolate liquor of cacao beans and is rich in flavanols, a type of flavonoid specifically found in cocoa and chocolate. Flavanols are a natural preservative, preventing chocolate from going bad in the way that other perishable foods spoil. Further, the risk of microbiological growth in chocolate is very low as the water activity (aw), the amount of free water in a product which promotes microbial growth in food, is low and ranges between 0.3 and 0.4.

Chocolate usually comes with a “best buy” date which is a reflection of best quality, not food safety.  While chocolate quality (texture, color, or flavor) may be affected after that date, it is safe to consume unless there are signs of spoilage—off odor, flavor, or appearance (mold).

Here’s a look at the various kinds of chocolate and shelf life of each:

Cocoa powder – Cocoa powder is the processed and ground product of the roasted cacao bean. The powder contains no fat or additives giving it a long or nearly indefinite shelf life. However, it may lose its potency. If properly stored, an unopened package of unsweetened cocoa powder has an indefinite shelf life.  Once opened, cocoa powder will retain its best quality if used within 3 years of opening, provided it is stored properly and packaging is tight. The same is true for “Dutched “or Dutch-process cocoa.

Unsweetened, bitter, or baking chocolate – Chocolates by any of these names are pure solid chocolate liquor containing 50-58 percent cocoa butter with no added sugar or milk. When stored properly, the cocoa butter in baking chocolate is very stable, as it has undergone tempering which stabilizes the cocoa butter. Thus, baking chocolate has a long shelf life but is at best quality for 2 years. 

Dark, semi-sweet and sweet chocolate – Chocolates in this group are dark chocolate and contain varying amounts of cocoa butter with the main difference being the amount of sugar and cocoa butter (15-70%) in each. The label may indicate a percent of cacao; the higher the cacao, the darker and more bitter the chocolate. Like baking chocolate, these chocolates, including chips, have a best-quality shelf life of at least 2 years. The higher the cacao percentage, the longer the chocolate tends to keep due to no- or less- milk and other perishable ingredients.

Milk chocolate – Milk chocolate contains at least 10 percent chocolate liquor plus milk solids and fats and sugar to give a sweet and creamy taste. For best quality, the shelf life is 1 year. The main reason milk chocolate has a shorter shelf life is because milk fat oxidizes and becomes rancid faster than cocoa butter.

Ruby chocolate – Made from ruby cacao beans, ruby chocolate has the most robust berry flavor in its first year but is safe to consume unless it molds. Ruby chocolate is sensitive to light, moisture, and heat causing fading and greying.

White chocolate – White chocolate consists of sugar, milk solids and fat, and 20 percent cocoa butter. Because it does not contain chocolate solids, it is not a true chocolate. Further, it does not contain the natural antioxidants of true chocolate, thereby making it prone to oxidation or rancidity when expose to light and air. As a result, white chocolate has a shelf life of about 6 months for best quality.

STORAGE

The shelf life of chocolate is dependent upon proper storage to preserve its flavor and appearance. These storage tips will insure the longevity of chocolate:

  • Store in an airtight container. Cocoa butter has an affinity to absorb odors and flavors of whatever is nearby. Further, an airtight container blocks out oxygen that causes chocolate to oxidize and lose flavor.
  • Store in a cool, dry environment. To maximize the shelf life of chocolate, store at room temperature between 65°F and 70°F and with a relative humidity of lower than 50-55 percent. Under these conditions, the cocoa butter and cocoa solids stay stable. 
  • Store in a dark location (pantry). Light, like oxygen, contributes to oxidation.
  • Refrain from storing in the refrigerator. Ideally, chocolate should not be refrigerated, as doing so may cause the chocolate to absorb odors from other foods and/or develop a moist surface when brought back to room temperature resulting in bloom. If refrigeration is necessary due to high temperature/high humidity, tightly wrap the chocolate to prevent both scenarios.
  • Freeze chocolate with care. Chocolate can be stored in the freezer for up to a year but does not significantly change the shelf life. Place the chocolate inside a covered, airtight container or a heavy-duty freezer bag to preserve flavor. Freezing chocolate may induce bloom due to temperature shock. Freezing is a good option for chocolate that will be used later for baking or melting.

BLOOM

Chocolate bloom describes chocolate that appears dusted or streaked with grey on the surface. Bloom does not affect either the taste or shelf life of chocolate nor does it render chocolate unsafe. Bloom only affects the aesthetic appeal of chocolate. Two types of bloom occur in chocolate: fat bloom or sugar bloom.

Fat bloom is a result of chocolate exposed to warm temperatures. Heat causes the cocoa butter to soften, separate, and rise to the surface leaving grey/white streaking. When running a finger gently over the surface, fat bloom feels smooth.

Sugar bloom is a result of exposure to humidity or moisture. The sugar particles in the chocolate absorb moisture. When the moisture evaporates, sugar crystals left on the surface leave a blotchy or dusty look and rough feel to the touch. Sugar bloom is most likely to occur with refrigerated chocolate.

Chocolate bloom is not reversible but it can be remedied by melting. By heating the chocolate, the fat or sugar goes back into the chocolate and when re-hardened, is without bloom. Melting works especially well with fat bloom; heating sugar bloom must be done with care as the chocolate may seize or change to a grainy form. Chocolate that has bloomed may also be used in baking.

Temperature shock can also cause bloom. If chocolate is to be frozen, place it in the refrigerator, unwrapped, for 24 hours prior to freezing. Wrap generously and freeze in an airtight container. At the time of use, thaw the wrapped, frozen chocolate in the refrigerator for 24 hours before bringing it to room temperature. Unwrap the chocolate after it reaches room temperature.

Chocolate is a shelf-stable product that does not become inedible or unsafe like other perishable foods.  It may lose potency over time. Proper storage and handling are the keys to the longevity of this delicious treat. 

Sources:

What is the Shelf Life of Chocolate (Products)?, Puratos
The Ultimate Shelf Life Guide, Still Tasty
Storing Chocolate for World Chocolate Day, University of Florida Extension, Sarasota County
Does Chocolate Go Bad?, WebstaurantStore
Death or Health by Chocolate? , University of Wyoming Extension
Does Chocolate Go Bad? , Southern Living

Marlene Geiger

I am a graduate of the University of Nebraska-Lincoln with a BS in Home Economics Education and Extension and from Colorado State University with a MS in Textiles and Clothing. I enjoy spending time with family and friends, gardening, quilting, cooking, sewing, and sharing knowledge and experience with others.

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