How We Source
Every number on this site comes from somewhere, and that somewhere is named and linked on the page it appears on. This page describes how sources are ranked and which ones we will not use.
The hierarchy
Tier 1 — primary and institutional. Government and university sources: USDA FoodData Central, the US cooperative extension system, federal composition standards, and published food-science texts. These are the strongest evidence available to us and they are searched first.
Tier 2 — specialist manufacturers and test kitchens. King Arthur Baking, America’s Test Kitchen, Bob’s Red Mill and similar. Authoritative within their own domain, and noted as commercially interested where that is relevant.
Tier 3 — corroboration only. Established food publishers, used to confirm a Tier 1 or Tier 2 claim. A Tier 3 source is never the sole support for a claim.
Rejected outright. Forums, Quora, Reddit, AI-generated summaries, other substitution sites, and content aggregators. Anything that cannot be traced back to a named origin does not get cited here, regardless of how often it is repeated.
That last rule does more work than it looks like it does. A substantial share of the pages that currently rank for these questions are built on exactly those sources, which is part of why their numbers disagree with each other.
Sources currently cited on this site
The extension system is searched before manufacturers, because in practice it is both more authoritative and more reliably accessible. Sources cited across the published pages so far include:
- US Department of Agriculture, Agricultural Research Service (FoodData Central)
- US Food and Drug Administration composition standards
- Colorado State University Extension
- University of Illinois Extension
- University of Maine Cooperative Extension
- Mississippi State University Extension Service
- University of Missouri Extension
- North Dakota State University Extension
- Utah State University Extension
- America’s Test Kitchen
- Bob’s Red Mill
How a source is recorded
Each one is stored with its title, publisher, URL, the date it was accessed, and its tier. The access date matters: a page that cited a source in 2026 is telling you what that source said in 2026, and sources change.
Where a source is a database rather than an article, we cite the database and the record identifier rather than a deep link, because those links are frequently unstable.
When sources disagree
We publish the disagreement. A worked example already on the site: two university extension services state the arrowroot-to-cornstarch swap at one to one, while America’s Test Kitchen, having tested it across three recipes, reports closer to one and a half to one. Both appear on the page, with a note on which to start from and what it means if your result comes out loose.
Resolving that silently would make the page easier to read and less true.
Reporting a source problem
Broken link, superseded guidance, or a source we have read wrongly — write to contact@pinchwell.com. See Corrections for how it is handled.