Water activity is one of those measurements everyone in the federation has heard of and fewer of us actually track on a regular schedule. It's not moisture content, though the two get confused constantly. It's a measure of how much of the water in a cheese is actually available for microbial growth, and it's a better predictor of shelf stability than moisture alone — which is exactly why our Food Safety Committee keeps asking us to put a webinar on it.
That webinar is on the calendar: Water Activity & Shelf Life, a free virtual session on November 25. Registration is open through the events page now.
What the session covers
The instructor walks through what a water activity reading actually tells you about a given wheel, how it differs by style — a washed-rind cheese and a hard aged cheddar hold very different numbers even at similar moisture percentages — and how to use a reading to set a realistic shelf-life claim on your label rather than guessing conservatively or, worse, optimistically. There's a section on the equipment itself: what a basic water activity meter costs, what it doesn't tell you, and when a reading is worth sending to an outside lab instead of trusting a bench unit. Trade coverage this fall of the bulk-cheese market has pointed out that even a commodity format like barrel cheddar, made to a fairly narrow moisture target, still varies enough lot to lot that buyers watch it closely — a useful reminder that moisture and water activity aren't the same number even in a style built around consistency. A label date that's wrong in either direction costs you: too short and you're throwing out sellable wheels, too long and you're the reason a buyer's return policy gets stricter.
There's also a practical piece aimed at smaller operations specifically: how to build water activity checks into a schedule you can actually keep, rather than a testing regime that looks good on paper and gets skipped the first busy week. If you've been through Listeria Control in Small Creameries, this session pairs naturally with it — the water activity number is one more input into the same environmental risk picture, not a separate conversation.
This is not a substitute for your HACCP plan, and the instructor is explicit about that up front. A water activity reading is one data point in a food safety plan, not a pass/fail test on its own, and nothing in the session should be read as a legal shelf-life guarantee for your specific product. If your state or a buyer requires a specific shelf-life validation study, this webinar will help you understand what that study measures — it isn't the study itself. A published shelf-life study on a mozzarella-style cheese we looked at while preparing this session tracked water activity alongside pH and moisture over a two-week storage window, and even there, water activity alone didn't explain everything the researchers saw — it was one line in a table, not the whole verdict. That's the caution the instructor wants members to walk away with.
Why the timing matters
Late fall is when a lot of members are finalizing holiday production runs and setting shelf-life dates for gift boxes and wholesale orders placed well ahead of the sell date. A water activity reading taken in November on a wheel that won't reach a shelf until January is a genuinely useful thing to have in hand, and it's a lighter lift than most members expect once you know what you're reading. A research review published in August 2025 looked specifically at whether the low-cost bench meters small producers can actually afford hold up against lab-grade equipment, and found them reasonably reliable for routine monitoring — useful news for members deciding whether a meter is worth the line item. The webinar won't get you a full lab study, but it will help you read one if a buyer ever sends you back a report and expects you to understand it.
The session is free, an hour long, and recorded for members who can't attend live. If you've been meaning to add water activity testing to your quality program and haven't found the on-ramp, November 25 is it. Bring your own bench meter's manual if you have one; the instructor takes questions on specific equipment during the last fifteen minutes.
The International Cheese Federation (ICF) and More Cheese are entirely fictional. This post is demonstration content created for MemberJunction. All people, organizations, events, courses, certifications, figures, and quotations in it are invented, and nothing here represents a real association, a real business, a real person, or real professional advice.