XMAX V4 Pro Review: The Sourdough Starter Kit

The Hook: The Sourdough Starter Kit

Dave went through a sourdough phase during lockdown.

Most people did. Few of them still bake. Dave's in the minority — five years on, there's a starter called Henrietta in his kitchen that he feeds on a weekly schedule, and every Saturday he turns out a loaf that makes supermarket bread look like insulation foam. The total cost of the operation, he'll tell you, is "about three quid in flour." The total time investment is "about twelve hours, spread across two days."

That's the argument for sourdough. Cheap inputs. World-class output. But only if you respect the process.

Rush the bulk ferment — under-proof the dough, over-hydrate, skip the fold schedule — and you get a dense, gummy, unpleasant loaf that tastes vaguely like disappointment. There's no shortcut. The technique IS the product. Dave spent his first three months baking bricks. Month four, he produced something edible. Month six, his bread was better than the artisan bakery down the road.

The XMAX V4 Pro is that sourdough starter kit.

The raw specs are cheap: a £89 pure convection portable with an 11-second heat-up, removable 18650 battery, and an adjustable airflow slider. The flavour ceiling it can reach is genuinely embarrassing to devices costing three times as much. The TinyMight 2 is still the flavour king at £299.99, but the V4 Pro gets you 85% of the way there for a third of the price.

But only if you learn the draw.

Pure convection doesn't work like hybrid heaters. You can't just inhale normally and expect clouds. The hot air has to pass through the herb at the right velocity, for the right duration, to extract properly. Short sharp pulls give you anaemic, half-extracted vapour. Long slow firm draws give you the dense, flavour-layered hits the marketing talks about. The technique is the product.

Dave borrowed mine for a weekend. He came back on Sunday and said: "right, I'm ordering one tomorrow." That's the endorsement that matters. Dave owns a Solo 2 from 2019 that still works. He doesn't buy vapes for fun.

Vapour Quality 8.5/10

Pure convection, done on a budget, executed properly.

The V4 Pro's heating chamber passes hot air through the herb at three adjustable airflow rates. No conduction from the chamber walls, no hybrid tricks — just convection extraction, the same method the TinyMight 2 and Arizer Solo 3 use to justify their premium pricing.

First draw at 185°C with a slow firm pull: pure terp clarity. The flavour hits you before the vapour does. There's a cleanness to pure convection that hybrid heaters can't quite replicate — nothing's cooking the bottom layer of herb while the top waits its turn. The airflow just heats everything evenly and delivers it.

The catch: if you draw like you're using a hybrid session vape, you'll get nothing. Quick light pulls don't give the airflow time to extract properly. The V4 Pro wants a 6-8 second draw, firm enough to pull significant volume through the chamber. It's a genuinely different technique from the V3 Pro, which forgives almost anything.

Once you've dialled the technique, the flavour range is the headline. Direct comparison to the V3 Pro (same session, same grind, same strain): the V4 Pro delivers brighter, cleaner terpene character. The V3 Pro hybrid heater gives you denser clouds earlier and handles technique mistakes better — the V4 Pro is the flavour win.

Compared to the TinyMight 2? The TinyMight is still in a different tier for raw extraction power — more thermal mass, more airflow headroom, more forgiving on draw variance. But in the flavour stakes, the V4 Pro is surprisingly close. At £89 versus the TinyMight's £299.99, that's not a comparison I expected to be making.

The Strain Test

Two street strains, two very different profiles. The point: seeing whether the V4 Pro's pure convection handles terpene layering at low temps and high-temp extraction with the same clarity — and where the technique learning curve bites hardest.

Wedding Crasher (Indica-Hybrid)

The Flower: Wedding Cake × Purple Punch — dessert genetics with grape notes underneath. 22-25% THC. Dominant terpenes: caryophyllene, limonene, linalool, myrcene. Sticky, dense bud structure. Evening strain — grape-vanilla on the nose, couch-lock incoming.

The Pack: 0.15g, medium grind, loose pack with 2mm headroom. Stage-1 airflow (most restrictive).

170°C, slow firm draws: First hit — grape lifts straight out of the chamber. The limonene-linalool layering is unmistakable at low temps. Three draws, wispy clouds, all flavour, no thickness. The slow 7-8 second pulls pay off here — you're pulling heat through the herb gradually enough that the terpenes come out in sequence rather than all at once.

185°C, same technique: Caryophyllene arrives. That peppery warmth layered under the dessert sweetness. Clouds thickening, grape still present. Four draws. This is the Wedding Crasher sweet spot — flavour layering is the whole pitch of this strain, and the V4 Pro's pure convection lets every note come through distinctly.

200°C (over water piece): Final extraction. Grape fades, vanilla-spice dominates, clouds go dense. Two draws through the glass mouthpiece connected to a 14mm bubbler. Without the water cooling, 200°C is too hot on the V4 Pro — I tried it straight first and the vapour was harsh enough that I put it down. Through the bubbler, entirely different experience.

Chocolope (Sativa)

The Flower: Chocolate Thai × Cannalope Haze — morning sativa with coffee and melon notes. 18-22% THC. 95% sativa-dominant. Dominant terpenes: terpinolene, caryophyllene, pinene. Fluffy bud structure, lighter than the Wedding Crasher. Nose: roasted coffee beans crossed with ripe melon.

The Pack: 0.13g, medium grind accounting for the fluffier structure. Stage-2 airflow (middle position).

180°C, slow firm draws: First draw — cantaloupe. The terpinolene-pinene combo reads as fresh melon more than coffee at low temps. Three draws, bright cerebral character already landing. This is where the V4 Pro's flavour clarity genuinely competes with the Solo 3 v2 — nothing between the herb and your lungs except hot air and glass.

195°C, same technique: The Chocolate Thai parentage emerges. Coffee-mocha notes developing underneath the melon. Clouds thickening properly. Four draws. The sativa lift is proper morning fuel — alert, not jittery.

205°C (over water piece): Roasted coffee dominates. Melon gone. Three draws through the bubbler — dense, creamy, sativa-focused extraction. This is where the WPA earns its inclusion in the box. At 205°C through the bare mouthpiece the coffee notes would turn bitter-burnt. Through water, they stay warm and coffee-roasted.

Chocolope's melon-to-coffee terpene arc is exactly the kind of high-temp strain the V4 Pro was built for — but only through the water piece.

— Dennis M., strain testing notes

Design & Build 7.5/10

Let's be honest: this feels like £89.

The V4 Pro's body is plastic with metal accents. The OLED display is small and functional rather than premium. The buttons are clicky in the way budget buttons always are. Hold it next to the Arizer Go SRT or the Mighty+ and the build gap is obvious.

But.

It's well-made budget. The body doesn't flex. The magnetic mouthpiece clicks securely. The airflow slider has genuine three-position detents, not a vague slide. The battery door — famously the V3 Pro's weak point — feels more substantial on the V4. Six weeks in, mine's still got all the functionality it shipped with.

Battery & Charging 8/10

The V4 Pro runs on a removable 18650 cell, which is the single feature that made Dave reach for his wallet on Monday morning.

Real-world battery life at 185-195°C: 6-8 bowls per charge on the stock 2500mAh cell. Push into 200°C+ territory and it drops to 4-5. Gentle on-demand hits stretch to 10. The swappable cell means Dave's stance is validated — carry one spare, never get caught short. He bought four extra 18650s when he ordered his V4 Pro. Dave's approach to battery anxiety is basically "be a prepper."

USB-C charging is universal and reasonably fast — about 2 hours to full from flat with a standard PD charger. Pass-through charging is supported, so you can keep vaping while it tops up.

Compared to the V3 Pro? Same 18650 system, similar per-bowl efficiency, similar charge time. No major battery upgrade on the V4 — it's the same proven platform with the same user-replaceable economics.

Ease of Use 7/10

This is where the V4 Pro's personality bites hardest.

The device itself is straightforward. Single button powers on. Plus and minus buttons adjust temp. Long-press on minus switches between session and on-demand modes. The OLED is small but readable. Magnetic mouthpiece clicks in and out for cleaning. No complications, no app, no presets to configure.

But the draw technique is a real learning curve — and pretending otherwise does first-time buyers a disservice.

Day one, I was drawing like it was my Mighty+: normal breath, 3-4 seconds, light pull. The V4 Pro produced thin, harsh vapour and I thought I'd bought a dud. Day two, I slowed the draws to 5 seconds and got marginal improvement. Day four, I was pulling 7-8 second slow firm draws and suddenly the reviews made sense.

The V4 Pro rewards technique learning. It punishes laziness. If you're the kind of person who reads the quick-start guide properly and adjusts, you'll be fine by day three. If you're the kind of person who expects a vape to work like every other vape you've owned, you'll hit the learning curve wall.

Cleaning & Maintenance 7.5/10

Budget cleaning expectations, budget cleaning reality.

The chamber is ceramic — easier to clean than metal ovens, harder to clean than glass paths. Resin builds up on the chamber walls after about 15-20 bowls and starts affecting draw resistance. Standard routine: brush after each session, ISO soak the chamber every 20 bowls, replace the chamber screen every 2-3 months depending on use.

The magnetic glass mouthpiece is the cleaning win. Drops into an ISO bath, cleans in minutes, slides back onto the device via magnet. No awkward threading, no stuck parts. After six weeks of daily use, my mouthpiece is still clear — ISO soak every 15 bowls keeps it immaculate.

The chamber screen is the consumable. A small mesh disc that sits at the bottom of the ceramic chamber and catches plant matter. It frays after 2-3 months of heavy use, airflow drops, and you replace it. XMAX sells them in packs — £6 for five, so about £1.20 per replacement. Factor it into ownership costs.

Portability 8/10

At 110mm × 32mm × 25mm and about 130g, the V4 Pro is genuinely pocket-friendly.

Fits in jeans pockets (actual jeans, not skinny jeans). Fits in jacket pockets without printing. Fits in a bag without taking up room. The magnetic glass mouthpiece protrudes slightly when attached — take it off for travel and the device becomes a smooth rectangular block that disappears.

The plastic body is an advantage here — light enough that you forget it's in your pocket. Compare to the Go SRT's 237g aluminium heft: different category. The V4 Pro is a go-anywhere carry vape.

Stealth: vapour's visible, device is discreet. The OLED is dim enough for cinemas. No noise beyond the faint click of the airflow slider. Used it on trains, at gigs, in pub gardens — unremarked on every time.

Value for Money 9.5/10

At £89, the V4 Pro is genuinely remarkable value. This is where the score floor lifts the whole review.

You're getting pure convection heating, 18650 swappable battery, USB-C PD with pass-through, 3-stage adjustable airflow, OLED display, glass magnetic mouthpiece that doubles as a 14mm/18mm WPA, 11-second heat-up, and session + on-demand modes. £89. I keep saying it because I can't quite believe it myself.

The V3 Pro is £89 and friendlier — for beginners, that's the right choice. The V4 Pro is £20 more for pure convection flavour that genuinely competes with devices three times the price. If you're a V3 Pro owner wondering whether to upgrade, ask yourself: do you enjoy learning technique, and do you want brighter flavour? If both yes, the £20 is worth it. If either no, stay with the V3 Pro.

Vs the Competition

Feature	V4 Pro	V3 Pro	TinyMight 2	Crafty+
Price	£89	£89	£299.99	£186.99
Overall Score	8.3/10	8.0/10	9.0/10	8.0/10
Vapour Quality	8.5/10	7.5/10	10/10	9.5/10
Heating Type	Pure convection	Hybrid	Pure convection	Convection-dominant
Heat-up Time	~11s	~18s	~5s	~60s
Swappable Battery	✓ (18650)	✓ (18650)	✓ (18650)	✗
WPA Included	✓ (glass mouthpiece)	✗ (extra)	✗ (extra)	✗ (extra)
Learning Curve	Steep	Gentle	Steep	None

Vs XMAX V3 Pro (£89)

The direct sibling comparison, and the £20 question that matters most. The V3 Pro is hybrid heating — faster to produce vapour, more forgiving of sloppy draw technique, and it supports POTV ONE dosing capsules. The V4 Pro is pure convection — brighter flavour, denser terpene clarity, but demands you learn the slow firm draw. If you're brand new to vaping, V3 Pro. If you're on your third device and care about flavour, V4 Pro. £89 is the cheapest flavour upgrade you'll ever make in vaping.

Vs TinyMight 2 (£299.99)

Different tiers, similar philosophy. The TinyMight 2 is still the pure convection king — more thermal mass, more airflow, more forgiving across draw variance, artisan build quality. The V4 Pro gets you 80-85% of the TinyMight's flavour experience for less than a third of the price. What you lose: build refinement, on-demand instantaneity, reliability confidence. What you gain: £211. If you already own a TinyMight, the V4 Pro is your lending vape. If you're choosing, the V4 Pro is the sensible buy unless flavour chasing is your whole identity.

Vs Crafty+ (£186.99)

The budget-convection versus premium-hybrid question at almost double the price. The Crafty+ gives you S&B's legendary reliability, app-based precision, Bluetooth control, dense consistent vapour, and a two-year warranty record that just works. The V4 Pro gives you pure convection flavour clarity, a swappable 18650 battery that'll outlast the Crafty+'s sealed cell by years, and £97.99 back in your pocket. If you want path-of-least-resistance convenience and you trust the S&B ecosystem, Crafty+. If you want the purer flavour experience and you're willing to learn the slow firm draw, V4 Pro delivers 90% of the Crafty+ experience at less than 60% of the price — and the battery situation means it'll still be running when the Crafty+ needs servicing.

Score Breakdown

Category	Score	One-Line Summary
Vapour Quality	8.5/10	Pure convection flavour that competes with devices three times the price
Design & Build	7.5/10	Budget plastic done properly — Marcus's sound-engineer ear clocked the airflow engineering
Battery & Charging	8/10	Swappable 18650, USB-C PD, pass-through — Dave's endorsement
Ease of Use	7/10	Device is simple; draw technique has a genuine learning curve
Cleaning & Maintenance	7.5/10	Easier than premium vapes, chamber screen is a consumable
Portability	8/10	Jeans pocket, jacket pocket, bag — 130g of go-anywhere carry
Value for Money	9.5/10	£89 for pure convection + 18650 + WPA-capable glass mouthpiece is a genuine steal
Overall	8.3/10	The budget-convection enthusiast box. Learn the draw, get TinyMight 2 flavour for a third of the price.

The Verdict

Dave ordered his on Monday. Marcus sent a text a week later: "Picked one up. The airflow's exactly what I thought it was." Two mates, two different use cases, both convinced.

That's the V4 Pro's verdict, delivered by other people.

For me, six weeks in, it's earned its spot in the rotation. Not my daily driver — the Solo 3 v2 and Mighty+ still share that job — but the device I reach for when I want specifically the bright, layered flavour that pure convection delivers. Mornings. Low-temp flavour sessions. WPA evenings with the bubbler.

Dave's sourdough starter kit is still going strong five years on. Henrietta's now an elder statesperson of starters, reportedly, and Dave's bread is better than ever. The point of a starter kit isn't that it produces great bread on day one. The point is that it rewards the person who learns.

The XMAX V4 Pro is that proposition in vape form. Cheap ingredients. High ceiling. Reward proportional to investment. If you're willing to learn the slow firm draw, you get genuinely remarkable flavour for £89. If you're not, you get an expensive lesson in why pure convection isn't for everyone.

Dave learned. Marcus learned in about three draws because his job is listening. I took a week. Your mileage may vary.

The V4 Pro is the sourdough starter kit. Patience is the ingredient. £89 is the bargain.

— Dennis M.