I'm currently away from home and staying in various places. At home, I enjoy eggs from a local farm..free range and no additives and no flax. I tried a couple of store eggs with labels that state the same, but flared and no luck. Then, I  checked the web for local farmers markets/ they usually give a list of the folks and farms that sell every summer. I have 3 times found good eggs this way...maybe you can try it. Dr Matia thinks the flaring was caused by flax in the feed..they don't seem to list it on the cartons?