A pile of fancy guavas all dolled up for sale.
Guavas are one of the most common fruits you'll find on the street. They are always in season and always popular for afternoon snack. Thai guavas are about the size of an apple, or slightly larger. The thin skin is light green while the meat of the fruit is usually white, with a very similar texture to an apple. At the center of the fruit is a cluster of small hard seeds about the size of a peppercorn. There are also varieties with pink flesh, although these are usually rare.
The fruit's Thai name can occasionally give birth to a bit of giggling over double meanings. The Thai name “farang” is also the Thai word for western foreigners. You can imagine the jokes that get made about 'eating foreigners' etc. The name gives away the fact that guavas are not native to Thailand. Like so many fruits and vegetables, we owe their introduction to the Spanish and Portuguese, who spread the fruit from the new world throughout the tropics.
In its native Amazonian rainforest, the fruit and the tree it comes from have many medicinal uses, most commonly for diarrhea and dysentery. It's also said that chewing the leaves before drinking can prevent hangovers. More scientifically, guava contains more vitamin C than citrus, and is rich in other vitamins as well as tannins, phenols, flavonoids and other good for you stuff.
The fruit often seems ubiquitous, appearing at all stalls and markets. Guavas must be eaten fresh, once cut the flesh begins getting mushy within a few hours. If kept refrigerated, they will last a day or two. You may also notice that the juice from the guava can stain your fingers brown if you eat it with your hands. It doesn't wash off easily but does wear off within a day or two. Given this property, it should come as no surprise that guava tannins can be used to tan leather or dye fabrics.
One of the reasons for guava's popularity is its low cost and wide availability. In the wholesale market, a full dozen may cost you less than 30 U.S. cents. If you purchase a fruit from a cart, the owner will slice it up in wedges for you. Most of them use an odd sort of knife with a wide corrugated blade that has its handle along the back of the blade. The fruit seller will quickly and deftly push the knife into the fruit and then give it just a tiny twist to separate a section. They can have a whole fruit cut up in just seconds. The fruit wedges will be tossed into clear plastic food bag, which the vendor will usually put into another small light weight plastic shopping bag along with a packet containing a mixture of sugar, salt and hot dried chili and one or two bamboo skewers to help you eat the fruit. All this extra service costs a bit more. You may pay ten cents or more for a whole fruit.