Jetboil
Jetboil Flash Java Kit 1.0L (2025)
- Weight: 6/10 How much it adds to your pack.
- Fuel use: 9/10 How much fuel it burns to boil a litre in calm air: less fuel to carry.
- Boil speed (calm air): 7/10 How fast the maker says it boils 1 litre in calm air.
Solo or two-person three-season trips where fresh coffee matters as much as boiling water
- Fuel
- Gas
- Weight
- 394 g
- Pot size
- 1 L
- Boil 1 L, calm air
- 4:00
- Fuel per litre
- 10 g
Packed size 19.1 cm long and 10.8 cm across Compare with a 2-litre bottle
Shorter than a 2-litre bottle and about as wide as one. Drawn to scale.
Where to buy
Trekitt £135.99 In stock. Free delivery. Free next-day delivery over £65. Topo colour. Shop shows a list price of £169.99 (20% off); page copy describes the upgraded auto-ignition and locking system.
View at shop: TrekittUltralight Outdoor Gear £159.99 In stock. Free delivery. Free tracked UK delivery on all orders. List price £169.99.
View at shop: Ultralight Outdoor GearPrices checked 8 Nov 2026 on each shop's own page; shops can change them. We earn no commission on these links; shops are listed by price. More
Our ratings (out of 10)
1 to 10, compared with the whole market. Each says what it's based on. How we score
Weight
From maker's figures 6/10How much it adds to your pack. 6: A bit better than average.
394 g is Jetboil's published system weight for the kit with its coffee press (Jetboil US page, also printed in OutdoorHub's spec box and Trekitt's listing). Jetboil says the figure leaves out the 27 g fuel stabiliser, as it does for the Flash 1.0L (371 g). The Adventure Portal lists 408 g for the system. Ultralight Outdoor Gear prints 450 g, a shop figure no other source repeats, which would sit on the 450 g line. All the other figures are in the 350-449 g band.
Fuel use
From maker's figures 9/10How much fuel it burns to boil a litre in calm air: less fuel to carry. 9: Among the best you can buy for this.
Jetboil says 10 litres per 100 g canister (Jetboil US page), which is 10 g per litre, under the 11 g line. OutdoorHub measured 8-10 g per litre in calm air.
Boil speed (calm air)
From maker's figures 7/10How fast the maker says it boils 1 litre in calm air. 7: Better than most.
Jetboil says 120 s per 0.5 litre (average over the life of a can), scaled to 240 s for 1 litre (scaled), in the 210-269 s band. OutdoorHub timed 95-115 s for 0.5 litre and 3 min 15 s to 3 min 30 s for 1 litre in light to moderate wind; The Adventure Portal timed 1 min 23 s and 2 min 56 s at 1,200 m in light wind.
What reviewers say (out of 10)
Ratings marked * are from reviews and are not part of the trip score. They are reviewers' scores, not our own measurements. How we score
Wind performance*
Reviewers' average 7/10How well it keeps boiling in a breeze.
8 reviews on wind performance, e.g. "the recessed burner and tall pot body provided modest protection".
Simmer control*
Reviewers' average 4/10How low the flame turns down without going out, for real cooking.
8 reviews on simmer control, e.g. "I could hold a gentle simmer for about 60 seconds before it either surged or threatened to blow out with a small breeze.".
In short
Good for
- Solo or two-person three-season trips where fresh coffee matters as much as boiling water
- Walkers who want a one-pot system with a built-in coffee press that packs inside the 1.0 L pot
- Trips where one litre at a time suits the group, on sheltered or moderately breezy pitches
Strengths
- Includes a silicone coffee press that stows inside the pot with the burner, stabiliser and a 100 g canister (packed 10.8 x 19.05 cm)
- Jetboil quotes 120 s for 0.5 litre; OutdoorHub timed 95-115 s, and 3 min 15 s to 3 min 30 s for 1 litre
- About 10 g of fuel per litre boiled (Jetboil: 10 litres per 100 g canister)
- 2025 turn-and-click igniter, three-point pot lock and heat-indicator cosy; OutdoorHub found set-up foolproof
Weaknesses
- 394 g before fuel and stabiliser, heavier than the plain Flash 1.0L (371 g), and the packed height is a tall 19 cm
- The press is flexible and packs flat, but OutdoorHub found its mesh filter thin and awkward to clean, and some grit gets into the cup
- Poor at simmering: OutdoorHub held a gentle simmer for only about 60 s, so it is for boiling, not cooking
- No regulator, so output drops in cold weather and as the canister empties; not for winter
- Boil times lengthen by 20-30 s in gusts (OutdoorHub), and the tall pot tips easily on uneven ground
Sources
We haven't tested this ourselves. Every score comes from these specs, tests and reviews.
ShowHide sources (11)
- Jetboil US: Flash Java 1.0L product page (specification table)
- OutdoorHub: OHUB review: Jetboil Flash Java Kit
- The Adventure Portal: The Jetboil Flash Java 1.0 L Fast Boil System
- Outdoor Gear Lab: Jetboil Flash review (Flash 1.0L, no press)
- Switchback Travel: Jetboil Flash 1.0L stove review (Flash 1.0L, no press)
- Live for the Outdoors: Jetboil Flash 1.0 camping stove review (Flash 1.0L, no press)
- We Are Explorers: Jetboil Flash 1L Fast Boil System reviewed and tested (Amy Fairall; 8 days and 100 km on the Great Ocean Walk in coastal wind; reviewer kept the sample) [the Flash 1.0L stove is the stove inside the Java Kit; no coffee press]
- The Great Outdoors (TGO): Jetboil Flash 1.0L Cooking System review (Chris Townsend; tested in the Cairngorms in winter 2025) [the Flash 1.0L stove is the stove inside the Java Kit; no coffee press]
- CleverHiker: Jetboil Flash Cooking System review (Brett Kretzer; page last updated 25 March 2025 for the new Flash, first published 2019 for the old one) [the Flash 1.0L stove is the stove inside the Java Kit; no coffee press]
- SectionHiker: Jetboil Flash 1.0L stove system review (Philip Werner; Jetboil donated the stove) [the Flash 1.0L stove is the stove inside the Java Kit; no coffee press]
- Treeline Review: Jetboil Flash 1.0 L Fast Boil System review, tested (Liz Thomas; boiled side by side with the previous Flash) [the Flash 1.0L stove is the stove inside the Java Kit; no coffee press]