About CanningDates

What this site will and won't do

CanningDates adjusts published, tested recipes using published adjustment tables — the ones in the USDA guide and on the National Center for Home Food Preservation's pages. It will tell you the added water-bath minutes and the corrected canner pressure for your elevation, exactly as those tables state them.

It will not invent a processing time, stretch a table past its last row, or split the difference between two bands. Where the published guidance ends — above 10,000 ft for a boiling-water bath, above 8,000 ft for a dial gauge — the tools say so plainly and point you to a weighted gauge or your county extension office instead of guessing.

Where the numbers come from

Nearly every band, pressure, yield, and brine quantity here is public-domain guidance from the USDA Complete Guide to Home Canning, Agriculture Information Bulletin No. 539, 2015 revision and the National Center for Home Food Preservation (NCHFP) at the University of Georgia. One source in the list below is neither: the last one, a university extension chart. Two rows of the high-altitude water-bath table come from it, and the paragraph after the list says exactly which and why. Everything is linked so you can check us:

• USDA Complete Guide to Home Canning (Agriculture Information Bulletin No. 539)
• NCHFP: Selecting the Correct Processing Time
• NCHFP: Using Pressure Canners
• NCHFP: Find Your Elevation
• NCHFP: How Do I? Can (per-food directions with quantity lines)
• NCHFP: Tomato Acidification Directions
• NCHFP: Quick Fresh-Pack Dill Pickles
• NCHFP: Bread-and-Butter Pickles
• University of Wyoming Extension: Home Canning Altitude Adjustments — the university-extension altitude chart (not a USDA or NCHFP page)

Here is the honest version of the high-altitude water-bath rows. NCHFP publishes four columns: no added time up to 1,000 ft, then five minutes, then ten — and then a single open-ended column, "above 6,000 ft," that adds fifteen minutes with no upper limit. The extension chart splits that open column in two: fifteen minutes to 8,000 ft, twenty from 8,001 to 10,000 ft, and there the chart ends. This site uses the split, and it had one test to pass — at every elevation it asks for at least as much time as NCHFP's open column, never less. Extra minutes at a full boil can only lengthen a process that was already tested.

That same extension chart also prints a dial-gauge row: 15 lb for 8,001–10,000 ft. That row is not on this site, and the difference is not arbitrary. Added minutes stay inside a process NCHFP has already published and left open-ended; a dial-gauge row sets a pressure on your canner that no USDA or NCHFP table publishes for that height, and there is no safe direction to guess in on a pressure. So the dial-gauge answers here stop at 8,000 ft, and the water-bath answers stop at 10,000 ft, where the extension chart itself stops — even though NCHFP's open-ended column would still say fifteen minutes up there. Past the last closed row anyone publishes, the tools say so and point you to a weighted gauge or your county extension office instead of picking a number.

Where the elevations come from

Each featured town's elevation comes from two public-domain federal records that have to agree: the nearest NOAA weather station, from the National Centers for Environmental Information station inventory, and the U.S. Geological Survey's Elevation Point Query Service reading at that station. A town where the two disagree by more than one adjustment band doesn't ship until a person looks at it.

Elevations are shown honestly as "about" figures — your kitchen may sit a little above or below the station. That is fine on purpose: the USDA adjustments work in wide bands (1,001–3,000 ft, 3,001–6,000 ft, and so on), so nearby elevation differences rarely change your numbers. Every town page names the band it used, and towns near a band edge say so.

Corrections

If any number on this site disagrees with the current USDA guide or a live NCHFP page, that is a bug — the most useful email you can send is the page here and the page there. Corrections ship fast: hello@canningdates.com.

Colophon

Static pages, no accounts, no tracking pixels, no cookie banner. The site reads federal tables and does band lookups, which requires knowing nothing about you — the one thing it stores is your saved town, in your own browser, so the label is waiting next time.