Help please with frenched lamb rack?!
If it's still in the vacuum sealed package, simply drop it in the freezer as is. If not, wrap it in plastic food wrap first, then in foil tightly and make sure the seals are good. The food wrap prevent sticking when you defrost it later on. It will keep easily for a couple of months.
You may want to consider making them into chops for more manageable portions. Myself, I would do four bone half racks, but you may like and prefer to do chops.....which I would then recommend in two bone portions.
Believe it or not, 20-30 years ago, the best lamb was considered to be imported Australian or New Zealand Lamb.....all of it was brought in frozen at the time. Now with better transportation and processing methods, imported lamb from these regions are brought to market more efficiently and the final product is cheaper .....but the product is no longer revered. Go figure.
For the record, I like Colorado Lamb by choice, but purchasing a full rack of imported lamb at Costco for less than $15 on a daily basis is one of the great benefits of membership for a lamb fix.