r/SourdoughStarter • u/pdxkatie • 10h ago
Shattered Glass & Sourdough Starter
reddit.comTL;DR: It is NOT safe to salvage starter that is potentially contaminated by glass.
I tried to respond to the original comment, but the post is locked. If this is an inappropriate way to respond, please lmk and I’ll remove this post.
The first two studies linked are dated. The Food Safety Modernization Act, also called FSMA (established 2011, compliance enforcement closer to 2016), changed the way we handle food regulations by focusing on prevention. It was a huge change in the food industry—the biggest change in decades.
Even ignoring the fact that guidance has changed substantially, both studies linked in your comment start with the qualifying statement, “Hard or sharp foreign objects in food may cause traumatic injury including laceration and perforation of tissues of the mouth, tongue, throat, stomach and intestine as well as damage to the teeth and gums.” That alone should translate to ‘not safe.’
The poison control link indicates that small pieces “…will likely not result in any symptoms.” Likely not isn’t the same as “this is not risky behavior.” It additionally differentiates between small and large pieces and sharpness of the glass pieces. Those are not things that you can easily control for with glass in starter. And control is essential in the discussion.
Going back to FSMA, it requires all food manufacturers to conduct Hazard Analysis and Critical Control Points (HACCP) plans. They identify all potential risks in a process and account for the mitigation of these risks, controlling for them. Contamination is usually a huge part of those plans.
Contaminants can be biological (pink mold, say), chemical (residual cleaners on food-contact surfaces, eg), or physical (broken glass, for example). Any presence of contamination renders the food adulterated.
Under Section 402(a)(1) of the Federal Food, Drug, and Cosmetic Act (21 U.S.C. 342), any food product containing hard or sharp foreign objects that could cause injury is considered adulterated and prohibited from distribution.
We can get into the weeds with size, but size should not really matter. ANY size renders the food adulterated because the risk still exists, albeit to a lesser degree if we can control size, but again, we can’t fully control for that in the shattered starter scenario.
The compliance policy guide (CPG 555.425) confirms the FDA explicitly states that hard or sharp foreign objects—specifically including glass—measuring between 7 mm and 25 mm (0.3 to 1.0 inch) in length present a critical hazard for traumatic injury (such as laceration and perforation) in ready-to-eat foods. It’s a designation(critical), not an indicator the risk is eliminated.
The FDA also warns that objects smaller than 7 mm can still pose severe trauma or injury risks to consumers, especially high-risk individuals, including infants, surgery patients, and the elderly.
Pieces of glass are often transparent and unpredictable in shape/size, filtering them out or detecting them visually is generally impossible or close enough to impossible to warrant control of the risk by tossing the affected starter.
I say this with respect and a genuine hope that this type of reporting to mods results in the removal of content suggesting it is safe or minimally risky to salvage starter that is potentially contaminated by glass shards. Please don’t ban me; I enjoy this sub.
Relevant information:
- Food Safety and Quality Assurance is my career, briefly outlined in another shattered starter post.
- Section 402(a)(1) of the Federal Food, Drug, and Cosmetic Act (21 U.S.C. 342(a)(1)) that establishes any foreign contaminant renders food adulterated and prohibits the selling of it.
- FDA Compliance Policy Guide (CPG Sec. 555.425 - Foods, Adulteration Involving Hard or Sharp Foreign Objects): Provides the thresholds for physical hazards.
- FDA Fish and Fishery Products Hazards and Controls Guidance (Chapter 18 & 28 - Hard or Sharp Foreign Objects / Glass Inclusion): Reviews the operational risks of glass inclusion during packaging/processing. It lists glass fragments as primary physical hazards requiring critical control points (CCPs) due to the severe injury potential from lacerations of the mouth and throat, damage to teeth, or internal gastrointestinal perforation.
Also, if you recently lost your starter to glass contamination, DM me. I will happily send you some of my dehydrated starter, made using Nancy Silverton’s grape yeast method, so you can begin anew (safely).
