Nottingham yeast - hydrate or not ?
 

The packet says hydrate for 15 minutes before pitching, many folks on here support adding dry yeast straight to surface of wort. Confusing.

The fact that huge numbers of people either pitch rehydrated yeast or pitch straight from the pouch indicates it probably doesn't make much difference.

Agreed. After reading hundreds of posts on the topic, and experimenting with both methods myself, my conclusion: It doesn't really matter.

Others may have different beliefs/experience, so maybe they'll chime in.

Not hydrating dry yeast causes loss of some of the yeast. If you're brewing a lower gravity batch, it probably won't matter much. But I rehydrate to make sure I have all the yeast I intended to have.

It's a pretty no-brain method to use the mr. malty yeast calc and decide for yourself. If the recipe calls for like .6 dry yeast packs, dump the thing dry into the fermenter. If it calls for .9 packs, maybe it's a good idea to rehydrate before you pitch, in order to get the most out of your $3.

My $.02.

To maximize your cell count and minimize stress/shock of the yeast, it is best to rehydrate dry yeast before pitching. This is an undisputed fact.

If you just want to make beer and don't have a very high OG, go ahead and just sprinkle the packet into your wort. It will work, but is not the optimal practice.

Not that I'm disagreeing, I know there's all kinds of science behind it, but if you're just going to state an "undisputed fact" instead of your personal experience comparing/contrasting the two methods, it would help to post a source so the OP can have an "undisputed answer".

Do a quick search on this forum and you'll find a bit of dispute to your "undisputed fact".

I don't think many really argue with the science behind it, but in practice it's pretty common for many to not really notice a difference.

The manufacturers say either is fine.

For rehydrating, Fermentis says to use 2x the weight of water to the amount of yeast, stir and let go 15-30 min.

For sprinkling on the wort, they say to sprinkle over the surface of the wort slowly to prevent clumps. Let sit for a few minutes and then aerate.

My rule of thumb is for up to 1.050 SG, use one packet, over that use 2 or more. I've sprinkled as directed, I've aerated prior to sprinkling, and only rehydrated a lager I did recently. Never had issues, and it's not something you really need to worry about it.

BYO or Zymurgy did a study on this and IIRC the pro tasters couldn't tell the difference as a whole between rehydrated and sprinkled.

A couple of years ago a bad batch of dry yeast was released that was defective. If I had rehydrated it beforehand it would have been obvious. I always rehydrate just to be sure.

My advice is if its lower then 1.055 then just dump the pack in with the wort. Higher then that rehydrate. Only reason i'd skip the rehydrating is the need to sanitize what cup/bowl/jar of whatever it is your rehydrating in and then the very small chance that if ur using tap water, something could be in the water. Again its a very small chance, but its not like ur cutting much of a corner by just adding it dry to the wort since we've seen x-amount of brewers skip that step and still end up with great brew.

And then of course just RDWHAHB