Educating consumers about milk processing, code dates and sustainability can impact knowledge, confidence and behavior

Confusion around code dates contributes to food waste at the consumer level. In the US, dairy is the second-highest wasted food category. This study aimed to 1) evaluate changes in consumer understanding of fluid milk code dates after targeted educational interventions, 2) assess the effectiveness of educational materials on consumer knowledge about pasteurization, ultra-pasteurization, milk code dates, and greenhouse gas emissions by the dairy industry, 3) measure changes in consumer confidence regarding milk quality, safety, and dairy industry sustainability practices, and 4) identify key behavioral and perceptual drivers of milk waste among consumers. Milk consumers over 18 (n = 233) participated in one of 20 focus groups held in Ames, Iowa, from February to March 2023. Each group, facilitated by 2-4 facilitators, received one of 3 treatments. All received a common treatment, composed of discussion prompts, a code date educational message (EM), and the "Decoding Milk" infographic. The common-treatment control groups (C) only received the common treatment; the sustainability infographic groups (SI) received an add-on sustainability EM and a sustainability infographic; the sustainability video groups (SV) received an add-on sustainability video and the sustainability infographic. Pre- and post-surveys were conducted (n = 233), and a follow-up survey was completed by 177 participants one month later. Panelists learned (P < 0.05) that pasteurization and ultra-pasteurization kill all harmful bacteria but not all spoilage bacteria, and that post-opening, milk should taste good for about 7 d. Panelists in the SI and SV groups learned that the US dairy industry contributes 2% of greenhouse gas emissions. Confidence in milk quality and safety, high at pre-survey, significantly increased post-intervention and remained very high at follow-up, regardless of treatment group. Confidence that the dairy industry is working to reduce greenhouse gas emissions significantly increased in the SI and SV groups and remained higher than C groups. Public EMs can clarify and build trust in code dates as quality indicators, encouraging milk consumption past its code date, and thus help reduce unnecessary milk waste.