Rouxbe

I have some wonderful stock from Thanksgiving. I wasn't as careful to skim and strain it before freezing. How long is it safe in the freezer? Does the presence of a little fat and a few particles impact its lifespan?

Frozen Stock will keep for months in the freezer. I just used some that I have had in my freezer for 5 months now, and it was perfectly fine!
And don't worry the little bit of fat and particles won't affect the lifespan.

I really like the Rouxbe recipe for rich chicken stock. I like to take it one step further. Instead of simmering on the cooktop for six hours, I put the stockpot into a 250-degree oven, often overnight. It's happy in there, unmolested by direct flame, and all of the goodness of the ingredients is distilled into liquid bliss. Try this with the tomatoes from your garden - use the same technique, but once the tomatoes are boiling on the flame, put the stock pot in the oven and let it barely bubble at 200-250 degrees for several days. Check it after the second day because it can caramelize as it is reduced, and it becomes the perfect flavor base for classic Mexican cuisine! Once your perfect tomato paste is cool, you can line muffin tins with Saran wrap and fill with gems of tomato, freeze, store in freezer bags, and in the middle of next year's worst blizzard you can add the fresh taste of High Summer to any dish.

I noticed the bottoms of the garlic heads were already either trimmed or cleaned of dirt and roots, and the leeks were not cleaned at all. Given that other recipe(s) on Rouxbe highlight the importance of cleaning leeks, I'm curious why the cleaning was omitted.

Secondly, I was talking with a chef the other day and he said he never uses celery leaves in his soups or stocks because they impart bitterness. (This is based on a test stock he made from celery leaves.) Is this your experience also?

I made this will I cleaned the house. What a great smell, certainly better than any cleaner.
I was so happy with the end result, really nice color with the tomatoes.