California Claro Walnut UnderdogUnderdog vaporizer (sold by Underdog Aromatherapy) is a log style vaporizer built out of a variety of high quality sustainably sourced wood. No two Underdogs are alike due to the nature of working with solid wood, and many designs have been retired as new ones are offered. This means that the Underdog you purchase is unique to you and has no external branding or serializing. In fact, the only “blemish” on the exterior the vaporizer is the power connector port.

What this means is that the when not in use the Underdog doesn’t look out-of-place on a nightstand or shelf while serving its secondary function as an aromatherapy diffuser. While I wouldn’t normally rate a plug-in vaporizer on its stealth, the Underdog gets high marks in that department.

Look and Feel

My UD is about the size of a soda can, is a gorgeous California Claro Walnut, and has a solid heft that makes it feel substantial in the hand. The bottom is an 1/8″ thick leather pad which gives the UD a bit of grip to keep from sliding across a surface.

How does it work?

The Underdog has a stainless steel heating core. Air is drawn into the Underdog, around the heating core, and up through the herbs in the stem. The wood on the outside insulates the heater to make the whole thing run more efficiently. My Underdog gets warm on the outside, never more than that. Given enough time to really warm up and hold onto all that heat, the Underdog can be used back to back without waiting for it to heat up again between draws.

How long it takes for your Underdog to be up to temperature and ready to use from a cold start will depend on the size of the Underdog. I like to wait about 40 minutes for my medium sized Underdog to warm up.

Plug in the power adapter and the Underdog will start heating up. No lights, no sounds. I added a VVPS (Variable Voltage Power Supply) connected in between my Underdog and power adapter to function as a temperature dial.

  • Standard: One temperature, a “happy medium”. No controls, no temperature adjustment.
  • VVPS: Voltage regulator, wide range of temperatures.

Once you’re up to temperature and read to get vaping you’ll have a selection of stems and attachments to choose from.


Each stem comes with its set of pros and cons.

  • Silicone Stem-The standard stem is a thick silicone stem with a bowl shaped screen that you shape and insert using a handy screen shaping kit that comes with the UD.
    • PRO:If placed correctly the screen will stay in place until you’re ready to change or clean it.
    • CON:It takes practice to shape and place a screen into this stem without multiple unsuccessful tries.


  • Glass Stem-The glass stem is actually a combination of a thinner silicone and glass. The silicone connects to the UD and holds the glass stem in place.
    • PRO:The screen in this stem is a smaller diameter and doesn’t require any shaping to fit in or replace.
    • CON:the screen can sometimes get dislodged while emptying the stem, be careful not to lose it.


  • Nylon Stem-The nylon stem will only fit into the newest generation of UD models and snaps into the heating chamber of the UD with a stainless steel tip for a solid fit. The stem itself feels solid and tapers at the top for a comfortable drawing experience.(Note: While I own a nylon stem, I haven’t used it due to incompatibility with my UD model)
    •  PRO:The step snaps into the UD, therefore has the most solid connection.
    • CON:The screen seems like it would be a pain to replace because of its snug fit into ridges built into the stem. (Note: I haven’t changed the screen on mine yet)


  • Glass 14mm Water Pipe Adapter (WPA) is currently my most used attachment. The attachment is fairly straightforward. On end attaches to the water pipe via a 14mm ground glass connection, there is an indent in the middle to hold the screen in place, the other end is open and fits all UD core sizes.
  • 18mm WPA is a combination of glass, wood and silicone. The glass serves as an insert into the 18mm tapered wood adapter and the silicone is attached to the other end of the glass and makes a solid connection with the UD. This is a must have attachment for those with larger 18mm water filtration pieces.
  • Copper aromatherapy cup sits on top of the heating element when the UD is not being use as a vaporizer. I use mine to hold beeswax with lemongrass essential oils mixed in, this creates a pleasant aroma throughout the room and the wax hardens when the aromatherapy cup is removed from the UD so as to prevent spills.

Power Supply

The UD comes with a choice of standard power supply or VVPS (Variable Voltage Power Supply). The standard model is a plug and play solution which will create a consistent ( but not customizable) vaporizing experience. The VVPS allows you to control the voltage (and therefore temperature) of the UD. One benefit of a VVPS is the ability to start a session at lower temperatures (for flavorful hits) and finish at higher temperatures (for maximum efficiency). The UD can be left on 24 hours a day with either power supply, but using a VVPS you can prolong the life of your UD by allowing you to turn the voltage down when not in use and turning it up right before use (for shorter warm up times). The VVPS can also significantly lower the lifespan of your UD by leaving the voltage cranked up for extended periods of time. I’ve opted for a standard power supply so as to have less “moving parts”.


The UD requires no maintenance short of occasionally rubbing the supplied Underbutter on the outside of the vaporizer to keep the wood looking fresh and healthy. In fact, the lack of moving parts means that the UD is a resilient vaporizer which can withstand some otherwise gnarly incidents. In my time using the UD I accidentally spilled the contents of my aromatherapy cup (beeswax and lemongrass essential oil) into the UD. Upon contacting the manufacturer I received a quick reply which simply stated that he’s done this a few times and the best thing to do would be to leave it on for a few days and let the wax and oil burn off. Since I’ve opted to leave my UD running 24/7 since purchasing it I retired it for a few days, when I returned to it i found it was running perfectly without any blemishes or foreign odors.


Overall I’m very happy with the UD, but a few things to note:

    • The top of the UD can become very warm, bordering on hot. This varies by both design and thickness of the wood.
    • The silicone/glass that connects directly to the chamber will become extremely hot. When you remove it make sure not to touch that end. I have burned myself multiple times by grabbing the hot glass end of my 14mm adapter shortly after removing it.
    • Due to its long warmup time it is most convenient to leave the UD on 24/7, this will shorten the lifespan of your UD. I have yet to see any side effects of this after months of use.

Final Thoughts

The UD has a large following on the FC Forums. There is a strong manufacturer presence there as well providing hints, tips, and support for folks with questions or concerns. All things considered, the UD is a high quality hand-built vaporizer with a high level of support from the manufacturer. If you can remember to avoid the hot ends of the stems you should have no problems.

If you’re looking to purchase an Underdog you can do so at Underdog Aromatherapy. You can use the coupon code VRBGoodies at checkout for free priority shipping on vaporizer orders and a few special goodies thrown in!