First, I'd take more care to investigate the goals and source of the workshop before attending. Then of I'd politely point out that the guidelines have changed substantially over 50 years. That the method she was teaching does not conform to the current USDA guidelines for safety and has not conformed to them since the early 1970s. Then move on and forget everything taught.

I would also contact the person who set up or sponsored the workshop and hope they had some interest in NOT passing on unsafe info.

Many of us have learned that you simply cannot teach an old dog new tricks and it is a waste of time to try. But if she voices any interest in learning more you can refer her to current editions of the ball Blue Book and NCHFP.

Dave

It was actually at a farming conference and was not billed as a canning workshop, which it wasn't. The presenter just talked about her practices and did have some jars and vegetables on the table that she used for very quick demonstrations of what to do in between talking about cooking from the garden/farm and making cooking easier by freezing and planning ahead. I was thinking of talking to the organizers because she was spreading info under their auspices.