Complex sentence: Curing can last up to 18 days but that makes very long-lasting red eggs that can last 40 days shelf life but eggs are stocked and replenished every two weeks interval so there is no need for the extra curing time.
Split into simpler sentences: Curing can last up to 18 days but that results in very long-lasting red eggs that can have a 40-day shelf life. The eggs are stocked and replenished on a two-week interval so there is no need for the extra curing time.