There was once a caterer which had the highest hechsher of Kedassia. He was catering a chasuna of 600 couples in a big hotel near the airport. He served MILICHIG ICE CREAM for dessert on FLEISHIG PLATES. Nebech all the people ate it. They did not know anything. The caterer made the order from the supplier and the supplier sent what HE WAS ASKED. The caterer put on the truck the WRONG ICE CREAM, I.E. MILICHIG ICE CREAM, NOT PARVE ICE CREAM! The caterer did not check the ice cream BEFORE serving the ice cream, nor did the full time shomer check the ice cream, and all the people nebech ate the milichig ice cream! The caterer only noticed that he served the wrong ice cream at 3:00 a.m. when he was loading everything with his workers on to the truck to take back to his factory. But he still put the dishes into a fleishig dishwasher knowing that the ice cream was milichig. (The plates were clean, cold fleishig plates, and he should have washed them in cold water with detergent by hand and then left them for 24 hours, before using again. The ice cream is cold, even though it was milichig). Yes, one has to know the hechsher one is eating or using.
I do kiruv teaching and was invited to a bat mitzvah from one of my students’ years ago. We were invited for the dinner in a fancy hotel. I called the hotel who was catering and then said, “inhouse catering”, therefore it is treif. I sent the father a very cordial and sweet email thanking him for the very kind invitation and we would love to attend the celebration, but we only eat Keddasia food and gave him the name and phone #, fax, email from the people who make airline food and supply the hospitals
(Hermolis). He ordered for us the most beautiful food, exactly the same as the others only Glatt Kosher Kedassia, in brand new china dishes, cutlery, new wine glasses, mevushal wine and wine opener, etc. It is all heated in an oven or microwave and triple wrapped. We opened it ourselves. It was a five course meal and we sat with another 2 frum couples who had the same food. The family thanked me publicly for all the work I had put in to the girl and her family and we are in touch till today. It was so wonderful and what a kiddush H-ashem it was for all to see, what we were eating and drinking. Everyone wanted our humongous portions and delicious food!
One should always know their butcher, (remembering Monsey!), fishmonger, and only eat hechsherim that are known to be reliable. There is a kashrus guide that is produced every year and is available at the Kosherfest with every hechsher in the world! The booklet is worth every penny! And, it is reliable and you can make your own decision of what is ok for you.
Gut Shabbos to everyone!