Curing a Yerba Mate Gourd
The Yerba Mate cup or vessel most commonly used traditionally is the fruit ( known as “gourd” or “mate gourd”) of the Lagenaria Siceraria, a climbing plant. Therefore the gourd or mate gourd is a natural plant product.
The expression “mate” has its origin in the Quechua vocabulary “mati” which means “recipient”.
The gourd is put to dry and hollowed out. Composed of 90 percent water, the gourd must  go through a process of evaporation outdoors for about three or four months.
In the drying process, the gourd will lose its fleshy membrane, leaving it hollow. When dry, the hard-shelled gourds are almost as hard as wood.
There are mate cups that do not need to be cured such as those made of non- porous materials (glass, metal, china, etc.) However, true mate lovers prefer a well cured gourd since it makes the beverage more tasty.
Gourds have a porous, fleshy texture on the inside. Some mate gourds may look “clean” on the inside and some other not. These ones can show some rests of dried membranes and even seeds (this is not very common though) on the inside which you can easily remove with your fingers or a scraping tool if the hole of the gourd is too narrow. Almost 100% of the mate gourds that are sold will look “clean” on the inside. If you see some spots in a new gourd, that´s perfectly normal. Not all gourds have an even color inside.
In the old days, the guaranà indians talked about taking away “the bad spirit” (initial bitterness) each gourd had. That´s where the expression “to cure a gourd” comes from. By “curing” the gourds, the indians prepared them to be the perfect recipient for their favorite drink.
The curing has one purpose : the removal of the inner soft tissues a “clean” gourd still may have. By removing the soft membrane it will insure that your first mate will not be so bitter. You may find on other web sites, books or booklets that you must use old yerba mate in the curing process. This is not entirely necessary as the gourd will finally get its proper taste after several uses of the mate.
The “curing” process has to be done only once when you first get a new gourd.
The best and fastest way in our opinion is to fill your new gourd with almost boiling water (boiled water could crack the gourd), let the hot water sit for approximately 5Â minutes. After this you may use a teaspoon and softly scrape any small remains of loose membrane the gourd may have under running water. If you have successfully removed the majority of the membrane you have completed the curing process. If the inside of your new gourd has nothing to scrape out (many of our gourds are this way), just put hot water (not boiling) let it rest 3 min and rinse.
However if you want to use your gourd right away you don’t have to cure it at all. The soft membrane will slowly be removed as you empty out the old mate and rinse with running water. The first couple of times the mate may have a more bitter taste by not curing it.
Please do not remove the stem in the center of the gourd. Doing so will cause the gourd to leak. Also, do not use any kind of soap to clean it.
GOURDS WITH METAL RIMÂ :
Add almost boiling water just below the lower part of the metal rim line.
The reason you do not fill the gourd above the rim line is to allow for it to expand and seal tightly with the rim. If you put the water above the rim line when you cure it, your gourd will, more than likely, leak although it may stop after two or three days use because of the continuing expansion of the gourd and the sealing of the rim as we said above.
GOURDS WITHOUT METAL RIMÂ :
Use the same procedure as above except you can fill it to the top with hot water.
GOURDS THAT STATE THEY ARE ALREADY “PRE-CURED” :
Pre-cured gourds have been carefully burnt in order to obtain a nice natural dark brown color. During the process the majority of the inner soft membrane is removed.
TIPS TO PREVENT OR REDUCE MOLD IN YOUR MATE GOURDÂ :
Any natural gourd can grow mold if not dried correctly since it´s a natural living plant and is not made of any synthetic product.
Also the leaves of the yerba leave a dark green tint (not harmful at all either) to the inside of the gourd which is not mold but just a bleeding of the color of the leaves. Some gourds may absorb more tint than others. You´ll also notice that this dark color is stronger towards the mouth of the gourd. This is due to the strong concentration of yerba that rises to the surface of the gourd there. This will not harm you in any way nor will make your mate gourd unuseable.
Please, do not panic if you see some dark spots like in the picture below after the very first uses of your new gourd. All new gourds develop those tiny spots when first used. Even brand new gourds may have some dark spots inside. THIS IS PERFECTLY NORMAL. Your gourd will be in top condition after several weeks of use and proper drying. With proper use, the gourd will finally get a slightly grayish-green uniform color. The pic below just shows the very beginning of that natural process. From time to time, it is also a good idea to rinse out the inside of the gourd with a little lemon juice, then plain water and let it sit out in the sun for a couple of hours. Sunlight is the worst enemy for mold. However, since the gourd is the fruit of a plant afterall, you can expect to see some spots inside it, even with proper care. Again, the better you dry it after use, the better.
TIPSÂ :
– After you have finished using your gourd for the day, it is very important that you rinse it well with warm water (no soap, please!!!), dry it out well with a paper towel and position it in a well-ventilated, warm place, preferably at a 45° angle so that the circulating air flows through the gourd.
– Once you finish drinking, thrown the used yerba, rinsed the gourd and dried it with a paper towel, sometimes it is a good idea to put the mate gourd mouth down near the stove for a few seconds so that the very hot air can accelerate the drying. Needless to say, this should be done very carefully. If you are a “sweet” drinker and generally add sugar or honey to your gourd, you must rinse it very well after use.
– It is also advisable not to leave your last brewing inside your mate gourd for more than 12 hours, especially if the weather is too hot. Letting the mate gourd dry out perfectly will help a lot. That´s why many drinkers have more than one gourd. If you have at least 3, this will allow 48hs of drying between uses which is perfect for seasoning them.
Always keep in mind that a mate gourd is a dried natural fruit that absorbs the color of the yerba mate leaves, consequently we will never have an absolutely stain-free gourd once we start using it.
Video on How to cure your Mate Gourd – Thanks Charles for your video review !