Confused

[orlando]

Quite a few observe that subsequent generations perform better. I think it has more to do with questionable quality of the initial yeast pitched.

that's my implication really. clearly the drying process is stressful and that's before you take into account everything the pack goes through to get to the point of pitching.
i'm probably at risk of getting off topic (and i'm trying not to let personal preferences overshadow too much!) but the difference in fermentation between a healthy pitch and a (even rehydrated) dry pitch is a telling indicator, for me at least.

I have read that repitching yeast that was from a batch of beer brewed with dry yeast isn't a good idea. Not done it so have no experience to report but wonder still why that should be the advice given.

[Kev888]

Interesting, if anything the re-pitched yeast usually seemed better to me! I suppose the characteristics can change somewhat, so not good for consistency between both batches. And for those who don't aerate well, or are unused to judging pitching rates of wet/harvested yeast, the second fermentation may be more problematic.

There was something mentioned by whitelabs regarding aeration/oxygenation and harvesting; the fermentation may still go adequately with relatively poor oxygen levels but the yeast are left in poorer condition for storing and re-use. Dried yeast don't need aeration for the fermentation, but maybe (just thinking aloud) the lack of it could still have some affect on the yeast thereafter?

[orlando]

That rings a bell Kev, something to do with what yeast do when shutting down after fermentation. In dried yeast it is in some way impaired. Doesn't account for those claiming to have no problems. But as I always say at this point, I haven't tasted their beer.

[tourer]

Well, i never Hydrate dried yeast, i either build a starter or pitch direct onto the wort If it's a liquid yeast i make a starter. I can't in all honesty say that there's much if any difference in the yeast performance of either method. I shall be trying the hydrating method in future with the "Jims" approach
Thanks everybody for your input