I've had a couple issues now with false positives in the lab for canned beer (using a mobile canner).
On occasion one of multiple samples from a can will show growth (BBT samples are clean and the other canned samples are clean), so I'm thinking it is in my can sampling technique.
My procedure is as follows-
-Wipe down lab bench with 70% alcohol.
-Working near an alcohol burner- no laminar flow hood, unfortunately.
-Can tops are flamed using a propane torch for 5 seconds prior to opening- opened by hand wearing nitrile gloves sprayed with alcohol.
-Samples taken using individually wrapped sterile pipettes and medium tubes inoculated and incubated.
Since all of my tank samples are coming back clean, it doesn't seem to be a lab environmental issue contaminating the sampling procedures.
My thought is that it is an issue with how I am opening and sampling the cans.
Anybody have different means of sterilizing the top of the can prior to opening?
Another more sterile means of opening it for sampling? Opening a can normally of course pushes the top of the can down into the beer which seems like a great way to contaminate a sample.
See any other issues with my process?
On occasion one of multiple samples from a can will show growth (BBT samples are clean and the other canned samples are clean), so I'm thinking it is in my can sampling technique.
My procedure is as follows-
-Wipe down lab bench with 70% alcohol.
-Working near an alcohol burner- no laminar flow hood, unfortunately.
-Can tops are flamed using a propane torch for 5 seconds prior to opening- opened by hand wearing nitrile gloves sprayed with alcohol.
-Samples taken using individually wrapped sterile pipettes and medium tubes inoculated and incubated.
Since all of my tank samples are coming back clean, it doesn't seem to be a lab environmental issue contaminating the sampling procedures.
My thought is that it is an issue with how I am opening and sampling the cans.
Anybody have different means of sterilizing the top of the can prior to opening?
Another more sterile means of opening it for sampling? Opening a can normally of course pushes the top of the can down into the beer which seems like a great way to contaminate a sample.
See any other issues with my process?
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