Bubblers can be made from a wide variety of materials. However, the vast majority available in today’s marketplace are glass bubblers. When it comes to choosing a quality bubbler, the most important thing to look for is glass type.
Borosilicate glass is a type of German-engineered glass. It is a heavy, durable, high heat tolerant glass. It is the same type that is used in scientific glass (beakers, test tubes, etc.) and in many types/brands of home bakeware (Pyrex). Heat tolerance is important because, of course, you’re going to be torching your pipe frequently. You’re going to need something that can handle the heat and not break under the constant pressure of being regularly exposed to a flame. Plus, you don’t want flimsy glass that will overheat quickly and scorch your herb. Always look for a bubbler made from either borosilicate glass, or that is made from “scientific glass” or “lab quality” glass, which is usually just another way to refer to borosilicate.
You may find bubbler pipes that don’t specify “scientific,” “lab-quality” or “borosilicate” glass. If this is the case, you should assume that it is made from another type of glass. This is not necessarily a bad thing. This factor may lower the price of the pipe, which is great if you’re on a tight budget. Just know that you must be extra-careful with other types of glass: be very careful not to overheat, and definitely don’t drop your pipe because it will almost certainly shatter. (Note: borosilicate glass is not unbreakable, but it can withstand impacts better than regular glass.)
Beyond glass type, everything else is a matter of personal preference. Some smokers prefer deep bowls, others, shallow ones. Some like long stems, others prefer shorter. Your own preferences will only become clear to you after you’ve tried one type and used it several times. For this reason, you might want to consider buying a cheaper bubbler and using it for awhile. By then, your preferences will probably have become clear, and then you can invest in a higher-quality bubbler or choose a different one to try out.
Less common are wooden bubbler pipes. Most contemporary smokers, particular younger ones, will gravitate toward glass ones. Wooden ones tend to have more appeal to older smokers. Wooden bubblers do not produce as clean a vapor as glass ones. They tend to contribute flavor from the wood to whatever herb is being smoked. However, some smokers like this, so that’s why wooden bubblers are still being produced.
If you’re looking for a wooden one, choose one made from some type of hardwood: walnut, maple and rosewood are common ones used for pipe-making. Bamboo, although actually a grass and not a wood, is also a great material for pipes. Just remember, as a general rule, wooden bubblers do not last as long as glass ones.