Usually the quality is not greatly different but the quantity is usually too low in my experience. Over here in the UK a 25l or 5Gal kit tends to come with 6 of yeast, where as I would often pitch 11-22g depending on the gravity.

It is probably the fact that pitching another yeast is pitching at far higher cell counts, laeading to far cleaner fermentations.

Anothe rthing is you never know how long the 'kit' yeast has been sat on a shelf out of the fridge, so may have degraded, more that a fresh pack of US-05, etc....

PS: Your terminology around Extract kit is correct :)

Usually the quality is not greatly different but the quantity is usually too low in my experience. Over here in the UK a 25l or 5Gal kit tends to come with 6g of yeast, where as I would often pitch 11-22g depending on the gravity.

It is probably the fact that pitching another yeast is pitching at far higher cell counts, leading to far cleaner fermentation.

Another thing is you never know how long the 'kit' yeast has been sat on a shelf out of the fridge, so may have degraded, more than a fresh pack of US-05, etc....

PS: Your terminology around Extract kit is correct :)