Using Frozen Yeast

I'm going to keep the group posted on my experiment with freezing and thawing yeast. I had about 1/2 cup sediment from a primary of Wyeast Cal. Lager yeast. This was almost a year ago. I mixed about 1 part to 9 or 10 parts vegetable glycerin/sediment. Kept it frozen. About two days ago I thawed the yeast, kept in a 1/2 cup Rubbermaid container, in the fridge and made up a 1 quart starter at about 1.040. Pitched the yeast when the starter became mildly warm to the touch. Occasionally agitiated the starter in the glass gal. jug. Am using two layers plastic wrap secured by a rubber band instead of an air lock. Was slow to start, but today seems to be at high krausen. Will make up another starter soon with 2 quarts at 1.040, and will pitch the new slurry into that. I plan to use this in a Pre-Prohibition Lager recipe.