Probiotic Juice Maker Skipped the Pathogen Kill Step, FDA Says

On September 29, 2026, the Food and Drug Administration posted a warning letter issued to Wellmill, LLC dba Vitamix Laboratories citing serious violations of Juice HACCP regulations. The agency determined that blending shelf-stable juice with live probiotics under non-aseptic, ambient conditions without a mandatory 5-log pathogen reduction step left products adulterated under federal law. The FDA said the firm's argument that a kill step would destroy the probiotics does not substitute for complying with the 5-log rule.

Key takeaways:

• On September 29, 2026, the FDA posted a warning letter to Wellmill, LLC dba Vitamix Laboratories citing serious Juice HACCP violations.
• The agency rejected the firm's claim that maintaining probiotic viability excuses the omission of a mandatory 5-log pathogen kill step.
• FDA said the firm's hazard analysis missed pathogen contamination during non-aseptic blending and bottling, bacterial growth from time-temperature abuse, and glass fragments, and that supplier certificates of analysis do not replace it.
• Wellmill told FDA it will no longer make and label the products as dietary supplements; FDA said juice HACCP rules apply either way.

What happened

On September 29, 2026, the FDA publicly posted warning letter CMS 725655, originally issued on April 20, 2026, to Michael W. Koschitz, President of Wellmill, LLC dba Vitamix Laboratories, located in Nesconset, New York. The letter followed an FDA inspection conducted from December 3 through December 12, 2025, at the company's juice processing and dietary supplement manufacturing facility.

During the December 2025 inspection, investigators identified significant deviations from the Juice Hazard Analysis Critical Control Point (HACCP) regulation set forth in 21 CFR Part 120. These manufacturing violations caused the finished juice items to be classified as adulterated within the meaning of section 402(a)(4) of the Federal Food, Drug, and Cosmetic Act, which applies to food prepared, packed, or held under insanitary conditions whereby it may have been rendered injurious to health.

The agency issued the formal warning letter under the authority of the FDA Human Foods Program, signed by Thomas Kuntz, Acting Deputy Director of the Office of Enforcement. The company sent several written responses in early 2026; FDA said it was issuing the letter to advise the firm of its continuing concerns and called the firm's hazard analysis response inadequate.

What changed

The central compliance failure documented in the warning letter involves the company's hazard analysis and pathogen destruction protocols. Wellmill operates as a secondary juice processor: it receives ready-to-use, shelf-stable juice blends and mixes them with a probiotic blend. The product is blended and packaged in glass bottles under non-aseptic conditions at ambient temperature, with no further treatment for pertinent organisms.

Under federal regulation 21 CFR 120.24, commercial juice processors must execute a treatment that achieves a minimum 5-log reduction (a 100,000-fold decrease) of the pertinent pathogen in the specific facility where the final packaging occurs. Wellmill performed no subsequent lethality step, such as pasteurization or a validated non-thermal equivalent, after introducing the probiotic cultures.

In its responses, Wellmill stated that post-blending pathogen reduction treatments are not feasible because they would destroy probiotic viability. The FDA wrote that this "does not substitute for compliance" with the 5-log requirement, and that a statement about product characteristics does not show compliance.

Furthermore, the firm maintained that biological hazards were not reasonably likely to occur because of prerequisite sanitation programs, supplier qualification, and finished-product lot testing. FDA called the response inadequate. It said a supplier Certificate of Analysis (COA) does not relieve the firm of its own hazard analysis for hazards introduced during its blending, ambient processing and glass bottling.

Who is affected

The regulatory scope of the warning letter addresses specific commercial juice beverages bottled in glass containers at the Nesconset manufacturing facility. The product names are redacted in the published letter, and it gives no distribution details, so it does not say where or how widely the products were sold.

Crucially, the warning letter does not report any confirmed consumer illnesses, hospitalizations, or positive pathogen test results linked directly to the manufactured lots. The FDA's enforcement action is based on the legal standard of insanitary manufacturing conditions and structural HACCP non-compliance rather than an identified outbreak or confirmed pathogen detection.

FDA's consumer guidance says children, older adults, pregnant women and people with weakened immune systems are at risk of serious illness from untreated juice. The letter names Salmonella, E. coli O157:H7 and Listeria monocytogenes among the pathogens the firm's hazard analysis had to address.

FDA posted another food-safety warning letter the same week, covered in FDA Warns Ohio Cheesemaker After 14 Listeria Swabs. For a look at a shelf-stable juice label, see Dole Pineapple Juice vs Fanta Pineapple: 4 Ingredients vs 13.

What it means for shoppers

For shoppers, the letter makes one point clear: adding probiotics to a juice does not exempt it from the juice safety rules.

When evaluating refrigerated and ambient juice products in stores, shoppers can keep several standard regulatory benchmarks in mind:

• Treated juice: FDA says most juice sold in the U.S. is pasteurized, and juice may also be treated by non-heat processes to destroy harmful bacteria.
• Untreated juice warning labels: Under federal rules, any packaged juice that has not undergone pasteurization or a recognized commercial kill step must carry a mandatory warning statement on the label: "WARNING: This product has not been pasteurized and therefore may contain harmful bacteria that can cause serious illness in children, the elderly, and persons with weakened immune systems."
• Sold by the glass: FDA does not require the warning for juice or cider sold by the glass, for example at apple orchards, farmers' markets, roadside stands, juice bars and some restaurants.
• Where to look: FDA says untreated juice is most likely to be sold in a grocery store's refrigerated section.

The public warning letter did not disclose whether the redacted Wellmill bottles featured the mandatory warning label while being marketed without a kill step. The letter does not mention a recall.

The background

FDA says it has received reports of foodborne illness outbreaks traced to fruit and vegetable juice and cider that was not treated to kill harmful bacteria. The Juice HACCP rule requires processors to analyze hazards for each juice they make and, when a hazard is reasonably likely, to control it with a written HACCP plan.

In the April 20, 2026 warning letter, the FDA outlined three distinct hazards that Wellmill failed to account for in its January 2, 2026 hazard analysis:

• Environmental pathogen recontamination: Mixing shelf-stable juice with probiotics at ambient temperatures under non-aseptic conditions creates clear opportunities for environmental recontamination by Salmonella, E. coli O157:H7, and Listeria monocytogenes.
• Time-temperature abuse: FDA noted that some pathogens, such as Salmonella and pathogenic E. coli, can grow and produce toxins above pH 4.0 (3.7 for Salmonella). With product held at ambient temperature and no documented room-temperature control, it said bacterial growth may be reasonably likely. The precise pH range of the firm's juice product was redacted in the letter.
• Physical glass hazards: Because the finished probiotic beverage was packaged into glass bottles, the facility was required to identify glass fragments as a potential physical hazard and establish critical controls to prevent broken glass from contaminating the product.

Between January and April 2026, the company submitted multiple rounds of written correspondence, including communications on January 16, March 12, March 17, March 30, and April 6, 2026. The firm informed regulators that it would cease manufacturing and labeling the items as dietary supplements and submitted revised labeling.

The agency noted that changing the product classification does not bypass juice rules. If the products are marketed as dietary supplements in the future, they must comply fully with Dietary Supplement Current Good Manufacturing Practice (21 CFR Part 111) in addition to fulfilling the Juice HACCP requirements under 21 CFR Part 120.

What to watch next

The warning letter instructed Wellmill to notify the FDA in writing within 15 working days of receipt, outlining the specific corrective actions taken to address the cited deviations. The agency warned that failing to adequately address the matter may result in legal action, including seizure, injunction, or administrative action to suspend the firm's food facility registration if criteria and conditions warrant.

FDA has not said publicly whether the firm has responded to the letter or changed its process.

The public letter does not reveal product names, illnesses, or where the products were sold. When buying packaged juice, check the label for the untreated-juice warning, and scan the product with the Aurascan app to see what each ingredient is.