A couple weeks ago, I attended a cachaca intensive with Minister of Rum Ed Hamilton and Cabana cachaca distiller Cesar Cestari. Here is some of what I learned.
Up to six grams per liter of sugar may be added to cachaca without declaring it on the label. Between six and fifteen grams is then called sweet cachaca and you can find it on the labels of Brazilian brands as "cachaca adocada."
June through December are the distillation months. At the Cabana distillery, they double distill cachaca in pot stills, but do it in a way I've never heard of before. During the harvest season, they distill all the fermented sugar cane juice just once and store it in large vats. The don't even cut the heads and tails at this point. This stabilizes the liquid, as sugar cane quickly goes bad like an apple that turns brown after you take a bite.
After they're done distilling sugar cane for the year, they mix the low-alcohol spirit together for consistency and do the second distillation. Then afterward, they add water and let it marry for a couple months before bottling.
Brazilian woods are harder than American/French oak and impart less flavor. There are tons of different woods in which cachaca is aged.
Cane grown for sugar is all about yield, whereas for cachaca it's all about quality. In different parts of Brazil, different types of sugar cane are grown best suited locally to make cachaca. Sugar cane grows in clumps. After you cut it down one year, the clumps become thicker and thicker. Every five years or so, they dig up the clumps and plant new sugar cane (just pieces of old cane) to start the process over.
Cachaca 51, or Pirassununga, is the third largest spirit brand in the world. There are 4000 brands of cachaca and about 30,000 producers. 1.3 billion liters of cachaca are distilled each year.
Molasses-based rums have a high sulfur content, so you need to age even the clear ones to take the edge off.
In order for cachaca to be called aged cachaca (meaning more than one year in wood), only half of the stuff in the bottle has to be aged for that long.
Also, there's a great cachaca quiz here at the Ministry of Rum. Test what you learned in this blog entry.