Zojirushi
Zojirushi Stainless Soup Jar
$21
Insulated Food Jar · RANK 01
SIGG
SIGG Gemstone Food Jar Selenite
Top Pick
Top pick: copper-layered 18/8 vacuum construction delivered just over 70°C after six hours in SRF testing. The bowl-lid and folding spork add utility without compromising its compact form.
$38 typical
EDITION 01RESEARCHED 2026-09-113 SOURCESREFRESH DUE 2027-03
SUBSTANCE SCORES
substance9.5/ 10
design8.8/ 10
value9.3/ 10
WHY THE PRICE IS JUSTIFIED
SRF's comparative test measured more than 70°C after six hours, and Stiftung Warentest called it the only “very good” jar. That performance and the copper-lined, 18/8 vacuum construction—not fashion positioning—explain the price.
MATERIALS
Jar body18/8 stainless steel
Durable, corrosion-resistant food-contact shell around the vacuum insulation.
Insulating layerCopper layer within double-wall vacuum construction
Reduces radiative heat transfer.
LidPolypropylene
Seals the jar and functions as a serving bowl.
CRITERIA
9/10
Build Quality
18/8 vacuum body and copper layer; strong drop/thermal-test showing.
10/10
Performance
SRF measured just over 70°C after six hours.
9/10
Value
€35 buys the strongest result in the Swiss/German comparison.
IDEAL FOR
- ·Long workday lunches
- ·Hiking
- ·Soup and stews
NOT FOR
- ·Microwave use
- ·Users who need dishwasher cleaning
DESIGN & ERGONOMICS
A folding spork and bowl-lid make it self-contained. It is a clean, restrained cylindrical object; hand washing protects the coated exterior.
LONGEVITY
Robust stainless construction. Hand-wash the exterior finish; the uncomplicated vessel and integrated utensil reduce loose accessories.
PRODUCT PHOTOS
EVIDENCE (3)
www.srf.ch
www.test.de
www.werecycle.ch
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Part of Insulated Food Jar · Edition 01 — see the full ranking