SOTO TrekMaster ST-331 Review: A lightweight, compact, and liquid-separate stove that's stable and resistant to low temperatures, making it perfect for mountaineering despite using a CB can
Written by Yosuke.C
Until now, the mainstream of gas stoves for mountain climbing has been models that use a type of gas cartridge commonly known as an "OD can." The other type, the "CB can," offers excellent cost performance, but is not structurally designed for use in the harsh mountain environments, so it can be said that it has tended to be used more for home use or camping. Overall, it is undeniable that CB can type gas stoves have always been out of reach for serious mountain climbers
The left is a CB can, and the right is an OD can
A new trend has been emerging in the world of gas stoves for the past few years. This is the introduction of a new type of CB canister that can withstand mountain environments and a compatible gas stove SOTO (Shin Fuji Burner) a leading domestic combustion appliance brand.
the Trek Master , the latest model released in 2025 among CB can type gas stoves, which is well suited to mountainous areas and low temperature environments, in the field, so I will now review it.
table of contents
- Key Features of the SOTO TrekMaster ST-331
- Detailed Review
- The "CB TOUGH" series of cassette gas cylinders makes it possible to use them in the mountains, even though they are CB cans
- Highly wind-resistant burner head shape
- Low center of gravity for high stability, large grate for large cookware
- Output that can boil water in a short time
- Equipped with a generator, it is resistant to low temperature environments
- The choice of CB cans is environmentally friendly and economical
- Not the lightest, but still packs compactly
- Summary: This gas stove is perfect for camping and mountain climbing! It can be used all year round
Key Features of the SOTO TrekMaster ST-331
The Trek Master is a separate stove that uses CB canisters. Its liquid-fired combustion system with a generator minimizes heat loss due to drop-down, providing stable heat even in low-temperature environments. Its low-center-of-gravity separate design enhances stability on uneven terrain, with a 2kg load capacity. The generously sized, approximately 16cm trivet can accommodate even large cooktops for multiple people, making it easy to adjust the heat and cook. Minimal parts and meticulous design ensure excellent portability—it fits inside a 450ml mug—and despite being a separate stove, it weighs just 195g. From light outdoor adventures to rigorous adventures, this new type of gas stove optimizes weight and cost performance for every occasion, ensuring maximum ease of use.
Favorite points
- Separate type with low center of gravity for high stability
- Output that can boil water in a short time
- Equipped with a generator, it is resistant to low temperature environments
- Highly wind-resistant burner head shape
- Compact storage
- More economical CB cans, and the flexibility to use either Tough or Normal depending on the situation
Points of concern
- Some quirks in operation, such as the need to preheat before ignition
- The range of heat adjustment is narrow
- There is a time lag between operation and response, so it can be irritating if you're not used to it
Main specifications and evaluation
| Item Name | TrekMaster |
|---|---|
| type | Separate type |
| Output (kcal/h) |
|
| Weight (g) | 192.7g (actual value) |
| material |
|
| Tripod size (Φ mm) | Approximately 160mm (measured value) |
| Load-bearing capacity | 2kg |
| size | Width 500 x Depth 140 x Height 105 mm (when in use, including hose) |
| Storage size | Width 90 x Depth 70 x Height 105 mm (when stored, including hose) |
| ignition device | none |
| 300ml boiling time | 125 seconds (when using ST-711/ST-712) |
| Outdoor Gearzine Review | |
| Combustion power | ★★★★☆ |
| Toughness (resistant to cold, long periods of use, and strong winds) | ★★★★★ |
| combustion efficiency | ★★★★☆ |
| Storage capacity | ★★★★☆ |
| Ease of use | ★★★☆☆ |
| Versatility | ★★★★★ |
| weight | ★★★☆☆ |
Detailed Review
The "CB TOUGH" series of cassette gas cylinders makes it possible to use them in the mountains, even though they are CB cans
CB TOUGH series. The larger one is CB TOUGH 220 (ST-712), and the smaller one is CB TOUGH 125 (ST-711)
As mentioned at the beginning, CB cans are generally made for home use. This time, I was most interested in finding out whether a stove that uses CB cans could be used for serious mountain use
SOTO offers a wide selection of CB cans, allowing you to choose the right one for your environment. Of these, the one we'd like to highlight is the " CB TOUGH Series " used in our field tests. Designed for use at high altitudes and able to withstand low temperatures, it contains the same three gases as OD cans (designed for mountain use): isobutane, normal butane, and propane. While this would have been impossible with conventional CB cans, they've achieved this gas blend by using a more pressure-resistant container (cylinder). What's surprising is that, despite this, it 's still priced more reasonably than OD cans
Furthermore, the lineup also includes a size that is slightly smaller than the standard CB can, making it a more portable choice. Its cylindrical shape makes it easier to store than OD cans, so it can be conveniently packed by simply slipping it into the gaps in your backpack
Since it is intended to be carried around, the cap can be attached to the bottom to prevent it from getting lost
The advent of cassette gas bottles suitable for cold climates has raised the usability of CB gas stoves to the next level, but the Trek Master can be used in the mountains. It's packed with technology to ensure it can be used reliably in harsh environments, so let's take a look at the features built into the unit.
Highly wind-resistant burner head shape
When I choose a gas stove, one thing I always pay attention to is its weather resistance. I especially check whether it has been designed to withstand wind. If the burner head is shaped so that it is directly exposed to wind, even a slight breeze can reduce the heating efficiency of the cooker, making it take longer to boil water and requiring extra fuel. The Trek Master 's burner head is equipped with a windshield to block the wind, so even in windy conditions the wind does not directly hit the burner head, allowing it to be used without affecting performance.
When we measured the time it took to boil 300ml of water, it took 125 seconds in a windless test, but 135 seconds in an environment with a wind speed of 3-5m/s, so the time to boil water was not much different. It is true that wind has a slight effect, but a difference of around 10 seconds is probably within the margin of error
Low center of gravity for high stability, large grate for large cookware
There are two types of gas stoves: "direct-connect" stoves, where the cartridge is attached directly to the main unit, and "separate" stoves, where the gas is connected to a separate location via a hose. The TrekMaster , has a low center of gravity due to the low position of the grate, which makes it more stable when a cooker is placed on it. Since it is not always possible to secure a leveled area in the wild, a stove with a low center of gravity and high stability makes cooking much easier.
160mm diameter, suitable for larger cookers
The Trek Master also has a load capacity of 2kg and a 160mm trivet, so it can accommodate large cookware. The trivet's shape means it can accommodate a wide range of cookware, from small, single-serving cookware with a diameter of about 10cm to large, multi-serving cookware with a diameter of over 20cm, making it easy to carry around for any occasion.
One thing to note is that there is a gap of about 8cm between the burner head and the center, and cookers with extremely small diameters will not fit on the grate, so be sure to check compatibility with your cooker in advance
Output that can boil water in a short time
The Trek Master has a maximum output of 3.0kW (2,600kcal/h) , and when we measured the time it took to boil 300ml of water in still air, it was able to reach a boil in 125 seconds (2 minutes and 5 seconds). 300ml is the amount of water needed to make Cup Noodles, and it's also the amount you often use when preparing hot water for a meal on a hike, as it's the amount you need to prepare instant rice and freeze-dried soup at the same time.
gas stoves designed for outdoor use the TrekMaster , but as a stove that uses CB canisters for home use, it is not just acceptable, but can be said to have very high specs. Currently, SOTO has a lineup of six CB canister compatible stoves, and the TrekMaster boasts a high output second only to the regulator stove "Range."
Equipped with a generator, it is resistant to low temperature environments
It wouldn't be so surprising if it simply had high output, but the TrekMaster is equipped with a "generator mechanism" and uses a liquid discharge combustion structure, which prevents a drop in flame power due to drop-down even in low temperature environments and maintains stable output.
The generator mechanism, combined with the CB TOUGH series cassette gas bottles, makes this stove suitable for mountain use
The part indicated by the arrow is heated and vaporized, enabling a stable fuel supply even in low-temperature environments
The "liquid discharge combustion structure" is a structure in which the fuel gas is sent to the burner body in a liquid state, heated by a generator, vaporized, and burned.Compared to the "vaporization discharge combustion structure" in which the gas is supplied to the body in a vaporized state, this structure has the advantage of being more resistant to low-temperature environments
Another benefit of the liquid combustion design is that it is less susceptible to drop-down. When a gas stove is used continuously, the heat of vaporization cools the gas cartridge, making it harder for the fuel to vaporize and resulting in a drop in output. This phenomenon is known as "drop-down." The Trek Master uses a generator to heat and vaporize the fuel as it burns, minimizing the drop-down effect.
Because it is a liquid discharge type, preheating is required before actual combustion, and it cannot be extinguished immediately
One thing that bothered me was that it takes about 30 seconds of "preheating" before it can actually burn. When you open the valve and light it, the gas is not fully vaporized, so immediately after lighting it (30 seconds according to the manual), you need to hold the cassette upright, and once the flame is stable, turn the stabilizer side down and lay the cassette on its side
Preheat the cassette gas in an upright position, and then lay it down after checking that it has started to burn properly
The Trek Master resistant to low temperatures and can be used in any environment , but because it requires preheating, it is not an entry-level model and is intended for experienced users. We do not recommend it as a first-time gas stove.
Also, since the fuel is supplied to the main body in liquid form and burns as it vaporizes, even if you close the valve, the fuel remaining in the hose will continue to burn, so the fire cannot be extinguished immediately.Please note that it takes familiarity and experience to handle this device
Adjusting the heat is difficult
Another thing that bothered me was the difficulty of adjusting the heat. Because the generator heats and vaporizes the food, there's a time lag between opening and closing the heat adjustment valve and the actual change in heat. As a result, adjusting the valve to reduce the heat doesn't respond immediately. Opening and closing the valve to adjust the heat is also quite strict. Even slightly opening it sets it to maximum heat, and closing it all the way shuts it off. While it's possible to adjust the heat, the valve adjustment is strict, so while it's easy to use for simple tasks like boiling water, it's difficult to use for cooking that requires frequent heat adjustments
The choice of CB cans is environmentally friendly and economical
In addition to the "CB TOUGH" series, there is a lineup of economical cassette gas bottles, such as power gas mixed with propane and regular gas, which is widely distributed.This means that you can save on running costs by using regular gas when camping on flat ground and the CB TOUGH series in high altitudes, mountainous areas, and cold regions
On the left is the CB TOUGH series, suitable for use in harsh environments, and on the right is the cost-effective regular gas
OD cans are lighter when using small cartridges, but are lighter than OD cans when using medium cartridges
Comparing the actual weight, the smallest model in the CB TOUGH series, the ST-711, weighs 220g (125g of gas), while the smallest OD can model, the SOD-710T, weighs 192g (105g of gas), so you might find it a little lighter than the OD can
For example, the total weight of the "Trek Master + ST-711" is 415g, while the total weight of the "Micro Regulator Stove FUSION Trek + SOD-710T" is 374g. If you are aiming for the smallest possible weight, the OD can type model is definitely slightly lighter
However, according to the official website , when compared with the large-capacity model "ST-712" of the "CB TOUGH" series, it is about 50g lighter than the OD can model which contains roughly the same amount of gas, so the CB can has the advantage.
As you can see, the question of "which is lighter?" is actually quite difficult to answer when it comes to weight. However, considering that there have been no small CB cans until now, the existence of the "ST-711" has made it possible to achieve a lightweight and compact can that is just as good as an OD can, depending on the number of days, type of mountain climbing, and combination with the stove itself. Considering the other benefits of CB cans, I get the impression that the weight is not something to be too concerned about for normal mountain climbing, except for lightweight hikers who are concerned about 10 grams
Not the lightest, but still packs compactly
Fits perfectly in a 750ml cooker
The Trek Master weighs 192.7g. When combined with the compact CB TOUGH series (ST-711), the total weight is approximately 412.7g. The Wind Master micro-regulator stove, designed for mountaineering, weighs approximately 67g, and even with the gas cartridge it weighs just 259g, which is by no means lighter than the compact type.
The Trek Master has enough functionality to be used for mountain climbing , but it is true that for mountain hikes that take multiple days, a compact stove that uses an OD can is still the winner. However, for day trips or overnight hikes, the weight of the equipment is lighter and the Trek Master is useful if you don't need to be as strict as on a mountain hike.
Due to the shape of the main body and the cassette gas, it is difficult to combine them all into one cooker, but the grates can be folded up to make it compact, making it suitable for use as a main stove on day hikes or hikes, or as a secondary stove when camping
Summary: This gas stove is perfect for camping and mountain climbing! It can be used all year round
We introduced the SOTO Trek Master , a gas stove that is sure to be a useful tool for enjoying a wide range of outdoor activities, including mountain climbing, camping, and barbecues
In the past, the only gas stove for mountaineering was an OD canister. the Trek Master , may be revolutionary in some ways. Will this stove become the catalyst for a fierce battle in the gas stove world? I look forward to seeing how gas stoves develop in the future.
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Yosuke
A person who travels around with just one backpack, with the motto of "as light as possible" without causing inconvenience
From spring to autumn, I go fishing in mountain streams in pursuit of char deep in the mountains. I hike the mountains in search of spectacular views that cannot be seen from the ground. I camp to relax by a bonfire. I snowboard to experience the feeling of floating in the silvery white mountains
A freelance writer with over 20 years of outdoor experience who enjoys the outdoors in his own way all year round. Based on his experience writing articles for over a dozen outdoor web publications, he will share his own experiences and the best tools he has used
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