Rehydration of dried yeast - benefit VS risk

[aidan]

Sometimes I rehydrate, sometimes I just sprinkle the dried yeast directly on the wort. I've not noticed any obvious difference but then again I've never done a side by side experiment. When I rehydrate I am aware of the extra opportunities for introducing contamination or untold variables introduced by temperature and duration of rehydration. So it is clear that the rehydration process has definate risks involved. I've just come accross this interesting report of experiments done to compare rehydration of yeast with dry pitching:

http://hwcdn.libsyn.com/p/1/a/e/1ae...01148169&hwt=d816c0eefc9c8f6a10c7bcdee67617a6

The conclusion is interesting:

Based on the described data it is recommended not to hydrate dry yeast since this may cause risks when not carried out in the proper way. Even when hydrating the yeast one might wonder what the benefit will be over the extra effort and risk.

Has anyone here done any side by side experiments on rehydrated vs. dry pirtching?

 

[Cyclman]

http://seanterrill.com/2011/04/01/dry-yeast-viability/

https://www.homebrewtalk.com/f163/dry-yeast-cell-counts-viability-473863/

 

[aidan]

http://seanterrill.com/2011/04/01/dry-yeast-viability/

https://www.homebrewtalk.com/f163/dry-yeast-cell-counts-viability-473863/

Interesting that rehydration temp seems to be of low importance in terms of yeast viability. However I would suspect that rehydration temperature is still a factor in terms of compounds produced and flavours developed in the beer.