Mayocobas are the creamiest and most buttery beans in the market. In fact they are so good that one man obtained a patent preventing anyone else from bringing them into the United States. Fortunately, that patent was revoked in 2008 and after ten years we are finally seeing these delicious beans become widely available here, although they are still more expensive than pintos.
The name means Flower of May. Mayocobas, also called Mexican yellow beans, are grown in Mexico, but originated in Peru, so they are also known as Peruanos or Peruvian Beans. Another name for them is Canario or Canary beans. Like all Phaseolus vulgaris, these beans are toxic to humans if not fully cooked.
If you would like to try these beans, please do not prepare them in a slow cooker, as that may not make them hot enough to become safe for eating. The FDA recommends soaking beans for at least 5 hours then discarding the soak water so that more toxins can be removed.
I cook them twice instead. I put the Mayocobas in the Instant Pot under high pressure for 10 minutes and let them cool before discarding the first liquid. Then I add fresh water and cook them another 80 minutes. They are similar in taste to Pinto beans and can be used in the same manner, but for some reason it takes twice as long for them to cook to my liking than do pinto beans. Nevertheless, I prefer the Mayocobas because when fully cooked the skins become very soft and also because they have a more delicate flavor.