To quote Harald Seitz from the Federal Centre for Nutrition: ‘whether you can still eat potatoes or not depends on what they look like'. But what does that mean?
Can you still eat potatoes when they start sprouting?
The golden rule is: If a wrinkled potato starts to sprout, you should put it in the organic waste or on the compost heap if you’ve got one! This is because when potatoes are germinating, poisonous solanine is produced. According to dgk.de, healthy potatoes have a solanine content of five to seven milligrams per 100 grams of potato.
However, if you ingest between 20 to 25 grams of solanine, which is the amount generally found in 500 grams of unripe green or sprouting potatoes, symptoms such as headaches and nausea can start to occur. The more sprouts there are, the more solanine there will be and the more toxic the potato will be. 400 grams of solanine can even be fatal.
If, on the other hand, the potato is still reasonably firm and is only sprouting in a few places, you do not necessarily need to throw it away. The potato should be used soon though, and you can just cut off the sprouts and peel the potato before cooking it.
How can you prevent potatoes from sprouting?
To prevent potatoes from sprouting so quickly, you have to store them correctly. It’s best to keep them in a cool, dry place away from direct sunlight. Pro tip: storing them with apples can help prevent sprouting!
Solanine is also found in tomatoes, but conversely, it decreases the more mature the tomatoes become. The opposite applies to these vegetables and so it’s best to eat them when they are a little riper! If you’re interested, this is the best way to store tomatoes and this is where most people go wrong!