Our Method
Before you trust anything else on this site, you should know exactly how it's put together. This page is that explanation, written plainly rather than buried in a footer.
Who runs this
The Hydration Code is operated anonymously. There's no founder bio, no author photos, no on-camera personality — deliberately. The reasoning is simple: a face doesn't make a citation more accurate, and we'd rather you evaluate the claims than a persona. When we're wrong, correct us in the same spirit — point at the source, not the byline, because there isn't one.
The site is reader-supported. We earn a commission when you buy a bottle through a link here — see the affiliate disclosure for specifics. That's the entire business model. There's no sponsored content, no pay-for-placement, and no bottle appears here because a brand asked to be included.
How sourcing works
Every factual claim on this site carries a source name and year, and every article ends in a numbered list of exactly what was cited. That's not a style choice — it's the whole basis of why you should believe anything we say.
The rule we hold ourselves to, verbatim from our internal build standard: a citation must
link to the source it names, and that source must be readable without payment. If we're
attributing a number to a journal, a government agency, or a research body, the link goes to that
body's own page — not a news article reporting on it, not a blog post summarizing it. If the
primary source is paywalled, we link an open mirror (like a PubMed Central record) or we cite a
different, verifiable source instead. A claim that's probably true but that we can't personally
verify against an actual readable source gets marked NEEDS SOURCE in our drafts rather
than shipped as fact. We would rather publish an article with a visible gap than one with an
invented study.
This has real consequences you can see in the published research: we've corrected our own homepage statistics more than once when a closer look showed the citation didn't actually support the number attached to it, and we've flagged studies with known methodological criticism rather than quietly presenting a single number as settled. Being the source that mentions the rebuttal is worth more to us than a cleaner-looking headline stat.
How we evaluate bottles
We look at the same handful of things for every bottle, in roughly this order:
- Material safety. What's actually in contact with the water — glass composition, lid material, any coatings — and whether that's backed by the same sourcing standard as our research articles, not marketing copy from the manufacturer.
- Real-world durability and use. Lid seals, cleaning difficulty, how it survives a drop, whether the capacity matches how it's actually marketed (a "commute" bottle that doesn't fit a cup holder is a real flaw).
- Honest tradeoffs. Every bottle we list has at least two real, specific downsides in its review. A recommendation with no listed downside is an advertisement, and we don't publish those.
What the rating actually means
The number next to each bottle (out of 5) is our own editorial score, assigned by
whoever wrote that review based on the criteria above. It is not an aggregate of customer reviews,
star ratings pulled from a retailer, or a survey of readers. We're explicit about this in the
structured data behind the page, too: bottle pages on this site publish a Review,
attributed to this site as the reviewing organization — not an AggregateRating, which
would misrepresent a single editorial judgment as a statistical aggregation of many people's
opinions. It isn't one, so we don't label it as one.
What we get wrong
We will get things wrong. When a figure turns out to be misattributed, outdated, or contradicted by later research, the honest move is a correction, not a quiet edit. If you find a citation that doesn't hold up, that's the most useful thing you can tell us — more useful than agreeing with the conclusion.