The Hidden Risk in Your Cans: Craft Brewer Lining Guide

aluminum can safety, beer can coatings, beer shelf life, BPA-NI coatings, brite cans, can linings, craft beer packaging, FDA regulations beer cans, packaging quality control, PFAS in packaging

The Hidden Risk in Your Cans: What Every Craft Brewer Needs to Know About Linings

08/29/2025

Why you should care (now):

I know, I know! You’ve probably been canning for years, and it might feel like you’ve got this dialed in. You Got This!!

But here’s the question: why should you care about can linings now?

If you’re running a craft brewery that cans beer, this applies directly to you. Craft beer lives and dies on flavor, freshness, and trust. You invest months into recipe development, fermentation control, and cold‑chain handling—but all of that work depends on one invisible layer inside your can. The internal lining, and the coating on the lid, are what separate your beer from direct contact with aluminum. If that barrier isn’t matched correctly to your beer style, or if it changes without you knowing, problems show up quickly: metallic notes, muted hop aroma, off‑flavors, discoloration, or even package failures.

On top of that, there’s new scrutiny around PFAS (so‑called “forever chemicals”) in packaging. Some fluoropolymer‑based coatings fall under this category, and several U.S. states have already begun phasing them out. Even if your supplier says “BPA‑NI,” that doesn’t automatically mean “PFAS‑free.” That makes it important to ask directly about PFAS status in your supplier’s Declaration of Compliance.

This matters more in 2025 than it did even a few years ago. Coating formulas are in transition industry‑wide, with many suppliers shifting to BPA‑NI chemistries. Supply chain variability means you might not always get the same liner system from lot to lot. And beer itself is more challenging on coatings than ever before—think fruit additions, high‑ABV pastry stouts, or heavily dry‑hopped IPAs. Add to that increasing regulatory and customer scrutiny on what’s in your packaging, and the margin for error is thinner than ever.

For breweries, paying attention to can linings isn’t optional detail work anymore—it’s now part of protecting the integrity of your beer, your shelf life, and ultimately your brand.

What changed (and why this matters in 2025)

Coating reformulations are everywhere. Many canmakers and coaters have moved from legacy epoxy systems to BPA‑NI polyesters/acrylics. Different platforms behave differently in beer—assuming “a liner is a liner” is how quality incidents start.
You’re probably using more than one can source. After the supply swings of the last few years, breweries commonly mix lots, sizes, or vendors. That increases variability in resin family, film weight, and end (EOE) coatings.
Beer styles are tougher on metal. Sour/fruited beers (lactic/acetic acid), high‑ABV stouts, and hop‑oil heavy IPAs stress the lining differently. Product chemistry—not just the coating—drives corrosion risk and flavor change.
Compliance and claims scrutiny is rising. Expect buyers (and some jurisdictions) to ask for BPA‑NI/“bisphenol‑NI” and broader food‑contact documentation. If you can’t produce it, you’re behind.

Bottom line: What worked fine two years ago might not protect your beer—or your brand—today.

What failure looks like (no drama, just facts)

Sensory: faint metallic/“coin” note, bitterness drift, muted hop aroma from scalping, or tart beers tasting harsher over time.
Visual: interior darkening, seam discoloration, or pitting on pull-down tests.
Package: sticky seams/leakers after warm storage or pasteurization; ends showing halo/rust.

If you’re only tasting cold, fresh cans, you’ll miss most of this.

A quick compatibility check that fits real brewery timelines

Not every brewery can afford to hold product for weeks before release. Here’s a practical approach that gives early warning signs without stopping production:

Confirm the system (body + end). Ask your supplier for the exact resin family of the body inside spray and the EOE coating, plus target film weight for each. Save the lot numbers.
Pull a few brite cans from the tank. Fill 6–12 cans of final beer at the same time as packaging day. Store half upright and half inverted at ambient warehouse temps (or warmer if you can spare an incubator/heat box).
Fast-track sensory. At 5–7 days, open samples side by side with cold‑stored product. Look for metallic, muted hop aroma, or unexpected sharpness in sours/fruited beers.
Inspect the can itself. Rinse and cut open a couple of empties—check seam area, interior body, and end for early haloing or discoloration.
Document & flag. Note coating specs, beer parameters (pH, ABV), and inspection results. If anything looks off, escalate with supplier before your next run.

This approach won’t catch every long‑term risk, but it will flag the obvious mismatches quickly—without halting your release calendar.

The 7 questions to put to your can/distributor rep

What is the internal coating resin family on the body and the EOE? (Polyester? Acrylic? Non‑BPA epoxy?)
What film weight are you applying/tolerances for body and end?
Is the system BPA‑NI / bisphenol‑NI? Provide a current Declaration of Compliance (FDA 21 CFR 175.300 or local equivalent) and migration data summary.
Any known limits for pH, ABV, salt/acid load, or hop oil exposure? Any beer style exclusions?
What’s your recommended in‑house check for beer? (Time/temp/orientation.)
How do you want empty cans stored/aged? (Temp, humidity, shelf‑life, handling.)
Who owns troubleshooting if we see corrosion or flavor change? (Contact, turnaround, and sample requirements.)

Quick guardrails by style (rules of thumb)

Sours / fruited / adjunct‑heavy: Always spot‑check. Watch pH < 3.5 and fruit acids. Consider polyester systems with a proven sour track record.
High‑ABV stouts & pastry beers: Alcohol + residuals stress liners; confirm end coating spec and film weight.
Hop‑forward (DDH, DIPAs): Hop oils can be scalped by some polymers; check aroma retention in fast‑track sensory.
Pasteurized beers (tunnel/flash): Verify pasteurization exposure in coating data; inspect seams/ends post‑process.

Your 60‑minute “Coatings Health Check” (do it this week)

Pull two cases of your three top sellers (and one sour/fruit beer if applicable).
Record can body/EOE lot codes, resin families, and film weights from supplier docs.
Start a 14‑day ambient warm‑hold (upright + inverted). Calendar a 7‑ and 14‑day review.
Line up triangle tests and a quick visual inspection checklist (inside body, seam area, ends).
If anything’s off, escalate with photos, lot codes, and your notes—you’ll get action fast.

What to keep on file (and ask for annually)

Current Declarations of Compliance (FDA 21 CFR 175.300 or applicable regional) for body and EOE coatings
Statement of BPA‑NI / bisphenol‑NI status and any PFAS‑related declarations your customers request
Migration/compatibility summary or data sheet for beer/acidic beverages
Change‑notification terms (so you know when the resin or film weight changes)

The Take Home 🍺

Can linings are invisible—until they aren’t. In a market where flavor, shelf life, and trust decide repeat purchases, treating coatings as a controllable variable (not background noise) is a competitive advantage. Put a lightweight protocol in place, tighten your supplier questions, and make coatings part of your standard release checklist.

Result: fewer surprises, better beer, and documentation that earns confidence with retailers and drinkers alike.