John,
I use 22 grams for my Spumante and the plastic stoppers are starting to push out, I don't think it is a stopper issue, I'd probably scale down to 19 grams, as you stated if there is any residual sugar, and I would bet that there will be, the pressure builds up fast!
Here is another way that is a little easier and works great, I got this from Bzac:
Buy encapsulated yeast, I believe I bought UVA Ferm 43, also known as Prorestart but ProElif® QA23 might even be better if you can find it. This is the QA23 baynus strain of yeast used for sparkling wines.
Here is what you need:
UVA Ferm 43, also known as Prorestart - found at
M&M Juice Grape in small affordable quantities.
Normal plastic champagne stoppers
Stainless Pipe Screens
Coopers Carbonation Drops - 2 per 750 ml Champagne bottle.
I put one gram of Encapsulated yeast in the plastic stoppers, pushed the stainless screens in to secure the yeast.
I rehydrated it in solution of warm water & sugar ( the instructions will give you the specifics)
I filled the Champagne bottles adding 2 Coopers Carbonation Drops (sugar) per 750 ml bottle, making sure that wine level is an inch or so from the top, put in the cook with the yeast (do not remove the screen, yeast must stay in cork).
Secure cork with wire cage, store bottle on their side.
Every day shake the bottle once or twice.
In 2-4 weeks, you have perfect sparkling wine with little to no sediment!
I tested a few bottles and it works well, I'll be opening another on Friday.