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."

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: an £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.

We stock the XMAX V4 Pro at HerbVape.co.uk — details and pricing below.

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 jar): 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 2's £299.99 — £210.99 apart — that's not a comparison I expected to be making.

Packing Guidance:

• Daily sessions: 0.15g, medium grind, loose pack with 2-3mm headroom
• WPA sessions: 0.2g, medium-fine grind, slightly firmer pack (the water filtration compensates for denser airflow)
• High-temp (200°C+): Always use water piece — the bare mouthpiece gets harsh at upper temps

The Strain Test

The flour never changes here — same jars, same grinder, same weight on the scales — which is the only way the sourdough argument can be tested at all: whatever's left on the table is either the oven or the baker.

Jack Herer — Sativa

The Flower: Same jar as every other device on this site. Haze × (Northern Lights #5 × Shiva Skunk), around 20% THC, terpinolene-led with caryophyllene and pinene behind it. Pale, spindly, hairy stuff that looks less impressive than it smokes — crack the jar and it's pine needles and lemon peel first, dry green herbs underneath, black pepper right at the back. Old-school in the way that means "aromatic", not "weak". It's the strain that shows you up: the top notes are fragile, and if a vaporiser can't hold them you find out in the first three seconds.

The Pack: 0.15g, medium grind, loose with 2-3mm headroom above the screen. Stage-1 airflow, the most restrictive of the three. Bare magnetic mouthpiece for the first two stages, bubbler for the third. Slow firm draws, seven to eight seconds each, because anything shorter on this device is just moving warm air around.

Low Temp (180°C): Three draws, and the first one arrives almost embarrassingly bright — pine needles and lemon peel, with that cooling mint edge sitting on top of them rather than buried underneath. Nothing has been sitting on a hot wall waiting its turn, so the fragile end of this strain gets to the mouthpiece intact. Clouds are wispy at this setting and I don't care. Draws two and three hold the citrus lift without noticeably thinning.

Mid Temp (195°C): Black pepper cuts through on the first pull and the pine steps back rather than vanishing — you can still find it behind the spice on draw one, which is more than most budget hardware manages. Three draws. Woody haze underneath by the third, dry earth arriving at the edges. This is where the airflow slider earns itself: at Stage-1 the pepper stays defined, at Stage-3 it dilutes into general warmth.

High Temp (205°C): Two draws, both through the bubbler, because the bare mouthpiece at this temperature is a mistake I have already made on your behalf. Earth and leather, a little light fuel behind them, the bright end long gone. Correct behaviour for this strain at this temperature, just arrived faster than I expected.

The Verdict: Eight draws, eleven minutes, and the first three of them are the reason this device exists. On draw one at 180°C the V4 Pro is doing something an £89 vaporiser has no business doing — the top notes read as clearly here as on hardware costing three times as much. The cost is speed and the cost is you: the same intensity collapses fast, and a lazy short pull turns all of it into thin harshness. That is the starter kit in one bowl. Feed it properly and it produces something remarkable; neglect it for one draw and it lets you know.

Wedding Cake — Indica-Leaning Hybrid

The Flower: Same jar as every other device on this site. Triangle Kush × Animal Mints, via Triangle Mints #23 — around 24% THC, caryophyllene first, then limonene and myrcene. Dense, squat, greasy nuggets that leave your fingers tacky and your grinder needing a wash. Nose is vanilla and cream over sweet raw dough, with a peppery earth underneath and a cherry-berry edge that turns up on the exhale more than the sniff. Modern dessert genetics doing exactly what it says on the tin. Where Jack exposes a device, this one flatters it.

The Pack: 0.15g again, medium grind, packed a shade firmer because the greasy bud settles anyway — chamber brushed and mouthpiece rinsed between strains, as always. Stage-2 airflow, the middle detent, which suits the heavier profile. Same slow firm draw, same seven or eight seconds.

Low Temp (180°C): Vanilla and sweet cream on draw one, sweet raw dough sitting under them, a cherry edge showing up on the exhale exactly where the jar said it would. Three draws. What's notable isn't that they're there — they're always there — it's that they arrive as three separate things rather than one lump of sweetness. Resolution is the whole test with this strain and the V4 Pro passes it early.

Mid Temp (195°C): Butter turns up, baked-cake warmth behind it, black pepper emerging on the second pull and the cherry deepening towards jam. Three draws, the densest of the session. This is also where the device bites: I got greedy on draw two, pulled too hard and too fast, and got a scorched edge on the exhale that took the next draw to clear. Firm is not the same as hard, and the V4 Pro is unforgiving about the difference.

High Temp (205°C): Two draws through the bubbler. Toasted and nutty, caramelised sugar tipping towards a burnt edge, peppery pungency underneath. Through water it stays drinkable; through the bare mouthpiece at this temperature it isn't, and that's not a preference, it's the reason the glass mouthpiece is a WPA in the first place.

The Verdict: Eight draws over twelve minutes, ABV out evenly golden. Both strains were still obviously two different plants at 205°C, which is the answer to the question this whole benchmark asks — this is a flavour device, not a delivery device. But the dessert profile is the one that exposes the V4 Pro's temperament rather than its ceiling: it never needed rescuing, so every good thing here is the device showing off, and the one scorched draw was entirely my fault and entirely the device's design. Henrietta doesn't forgive a skipped feed either. You get out what you put in, and on the days you can't be bothered to put anything in, pick up something else.

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.

The real story came when Marcus picked it up.

Marcus has been my mate since we worked at the same company in London years ago — both United fans, both the kind of people who'd step outside for suspiciously long breaks. He came up from Harlesden for a weekend recently, and works as a sound engineer, which means his listening attention is calibrated differently to most people's. We were sat in the garden, running the V3 Pro and V4 Pro side-by-side, same jar, same temp, swapping every other bowl.

He picked up the V4 Pro on the third bowl, took a draw on Stage-2 airflow, and said: "The airflow's opened up. You hear that? V3 Pro was tighter."

I didn't hear it. I was too busy tasting the vapour. Marcus pulled again, cocked his head. "Different sound character entirely. V3 Pro draws like it's working. This one's breathing."

He moved the slider to Stage-3. Another draw. "Yeah. That's a restrictor change." Then, without looking up: "You didn't need to spend three hundred quid on the TinyMight."

Marcus doesn't get excited about devices. He gets excited about sessions. But he clocked the airflow engineering in three draws flat, which is the kind of observation only someone with a trained ear picks up. The slider isn't marketing — it genuinely changes the acoustic signature of the draw because it's changing the airflow restriction profile through the chamber.

Materials:

• Body: ABS plastic with metal reinforcement, matte finish
• Chamber: Ceramic
• Mouthpiece: Magnetic glass (removes for WPA use)
• Airflow slider: Three-position detented metal slide

Battery & Charging (The IT Guy Check) 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 2550mAh 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.

The Amit argument applies here again: sealed-battery portables in this price bracket are time bombs. They work until they don't, and when they don't, you're binning the device. Amit has had three sealed-battery devices die on him across two continents. It's physics, not luck. The V4 Pro's 18650 design makes it last as long as you're willing to swap cells — which could be five years, not eighteen months.

The Spec Check:

• USB-C: ✓ (universal charger)
• Pass-Through: ✓ (vape while charging)
• Replaceable Battery: ✓ (18650 cell, widely available)
• Charging Time: ~2 hours flat-to-full

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.

Dave explained it better than I can. He picked mine up on Saturday, took two draws, and said: "You're drawing like it's an Arizer. This wants a bong pull." He slowed down, firmed up, pulled for a full 8 seconds, exhaled a chest-full of proper dense vapour, and nodded. "There it is. Learn that technique. You'll save yourself £89."

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.

Could Mum use this? Not intuitively. She'd need a five-minute tutorial on the draw technique. Session mode at low temp with a carefully explained slow firm pull? Yes. Anything else? Not a first-timer's device.

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.

Workflow comparison: cleaning the V4 Pro takes about 5 minutes for a proper ISO soak. Cleaning the Mighty+ cooling unit — eight o-rings, three separate parts, those tight corners that trap resin — takes 25 minutes. This is the budget vape compensating for build with easier maintenance.

My workflow:

• After each session: Tap out AVB, brush the chamber, wipe the mouthpiece rim
• Every 15-20 bowls: ISO soak the glass mouthpiece, chamber screen inspection
• Every 2-3 months: Replace chamber screen if airflow's dropped

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.

The water piece use case changes the portability conversation. At home, the V4 Pro lives next to my bubbler — the magnetic glass mouthpiece slots straight into a 14mm female joint, and the device transforms into a genuinely impressive at-home setup. Take the mouthpiece off, the V4 Pro is pocket-ready. This dual-use design is smart.

How I Actually Use This

My Default Setup: Stage-2 airflow (middle position), 190°C session mode, 0.15g medium grind, loose pack with headroom. Slow firm 7-second draws. Magnetic mouthpiece attached for on-the-go, removed for home WPA sessions.

When I Reach For It: Any time I'm actively choosing technique over convenience. Morning micro-sessions when I want flavour clarity. WPA sessions at home when I want the pure convection experience through water. Day trips where I need something cheaper than my Go SRT that I don't mind tossing in a rucksack.

When I Don't: When I'm tired, distracted, or just want vapour without thinking. The V4 Pro punishes inattention. On lazy nights, I reach for my Mighty+. When I want to share a vape with a mate who doesn't vape much, I hand them the V3 Pro — the V4's learning curve is too steep for casual users.

The Honest Cleaning Reality: I should ISO-soak the mouthpiece every 15 bowls. I actually do it every 20-25 bowls when draw resistance starts creeping up. Still easier than any cooling unit teardown I've ever done.

Session Frequency: Daily since it arrived. Six weeks of solid testing — it's earned its permanent spot in the rotation, which is higher praise than it sounds like given how many vapes I already own.

Medical Use Notes

For Pain Management: The V4 Pro's pure convection delivers efficient cannabinoid extraction at lower temperatures than conduction vapes need to hit the same effect. That matters for lung-friendliness when you're medicating multiple times a day. Session mode at 190°C with slow firm draws gives me gradual absorption across 10-12 minutes — similar experience to my Mighty+ but with brighter terpene character.

For ADHD/Focus: On-demand mode (long-press minus to switch) works well for micro-dosing. Two slow firm draws on Stage-1 airflow at 180°C, two minutes of focus, back to work. The 11-second heat-up is genuinely useful for the "don't break the task flow" thing ADHD brains struggle with.

The Medical User's Concern: The draw technique learning curve is a real consideration for medical patients with dexterity issues, pain flare-ups, or cognitive fog days. On bad days, the V4 Pro is frustrating. Session mode forgives more than on-demand. Keep a more forgiving device in rotation for flare-up days.

Session Timing: First draw to noticeable pain relief: 3-5 minutes. Duration: comparable to hybrid vapes. The efficiency is slightly better due to pure convection extraction — 0.15g on the V4 Pro does the work of 0.2g on conduction-heavy devices.

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 competition at this price:

• V3 Pro (£79.99): Hybrid heating, friendlier draw technique, dosing capsule support, similar 18650 system. The beginner-friendly choice
• XMAX Starry V4 (£69.00): Budget hybrid, bigger chamber, 18650 battery, slower heat-up. The entry-level option
• POTV ONE (£99.00): Hybrid, dosing capsule champion, proven reliability. Different philosophy
• Arizer Air SE (£72.99): Glass-path session vape, different category entirely, and cheaper again

The V3 Pro is £9 cheaper and friendlier — for beginners, that's the right choice. The V4 Pro is £9.01 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, £9.01 is the cheapest upgrade decision you'll ever make. If either no, stay with the V3 Pro.

Dave's math: He bought the V4 Pro for £89 plus four spare 18650s (~£24). Total £113 for a vape that'll last as long as he's willing to swap cells. Compared to Tom's sealed-battery Crafty+ (£186.99, and its cell degraded inside 18 months), Dave's argument writes itself.

The Verdict (The Bookend)

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.

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.

Category average is 8.0. The overall sits above it because the flavour-per-pound on offer here outweighs the build and ease-of-use scores that drag the average down.

Vs the Competition

The direct sibling comparison, and the £9 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. £9 is the cheapest flavour upgrade you'll ever make in vaping.

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 save: £210.99. 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.

Entry-level versus enthusiast. The Starry V4 is hybrid, bigger chamber, slower heat-up, same 18650 system, broader beginner appeal. The V4 Pro is the enthusiast upgrade — better flavour, faster heat-up, adjustable airflow, pure convection. At £89 versus £69, the Starry V4 is the better first-vape choice. For enthusiasts rotating through devices, the V4 Pro is the upgrade worth the £20.

The budget-convection versus premium-hybrid question at more than double the price. The Crafty+ gives you S&B's legendary reliability, app-based precision, Bluetooth control, dense consistent vapour, and a 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, the V4 Pro delivers 90% of the Crafty+ experience at 48% of the price — and the battery situation means it'll still be running when the Crafty+ needs servicing.