Proof dry yeast, or just pitch it?

Been brewing for 30 years and have never used anything but dry yeast and have never done anything different than sprinkle it into the cooled wort. I gently agitate after adding the yeast to help disperse clumps, but these would dissolve eventually anyway. I prefer to avoid steps like hydrating dry yeast that I feel are unnecessary and may only increase the chance of infection even if only a small chance.

I contend that most manufacturers recommend hydration because it will set off the yeast slightly sooner, and that seems to be an accepted benchmark for judging the quality of yeast, valid or not.

Keep it as simple as possible. If you use dry yeast, simply sprinkle it over wort and seal. This has worked every time for me over a period of 15 years plus.

there is a bit of confusion here. I see several divergent answers to this question

The confusion seems to be between hydrating, proofing & creating a starter. These are different and are for different purposes.

!st, hydrating: getting the dry yeast wet in order for it to be mixed evenly throughout the wort. Fermentis suggests dissolving their yeast in sterile wort or water and mixing it into a paste. The resulting paste will spread more evenly through the wort. This is not an issue for a liquid yeast user.

2nd, proofing: I think this is really a technique for bread making. Proofing involves mixing the dry yeast with a small ammount of sugar, waiting 15 minutes or so to ensure yeast activity (foaming) and then proceeding to mix the yeast in to the dough ingredients. There are two reasons that this may not be advisable: one is that bread yeast is almost always much more active that beer yeast and the proof with bread yeast will show activity very quickly, while a beer yeast proof may not. Second, I've seem to remember some cautions about using anything other than wort to get the yeast going since other sugars lack necessary nutrients for healthy yeast growth.

3rd, making a starter: this is a technique for sourdough & brewing. In brewing, the yeast is mixed with a somewhat dilute wort (I think Greg Noonan's New Lager Brewing suggests 1.03 - 1.04) several days ahead. (User48 has a great answer explaining the process in the question that's linked above). The advantage of a starter is to increase the yeast cell count so that it is sufficient to ferment the wort quickly.

Hope that helps!

With quality dry yeast on a normal gravity beer, I just pitch it in directly. I have not had any problems with poor/slow fermentation or off flavors. Please note the word quality - if the yeast is old or somehow questionable play it safe. Various Danstar and Fermentis yeasts have always rewarded me with fast and vigorous fermentation after pitching directly. I swear, dry yeast must be on steroids or something.

It's always a good idea to rehydrate dry yeast before pitching, and if your OG is above ~1.080, a starter is recommended.

Many yeast manufacturers don't require rehydrating their yeast, but it's generally regarded as a marketing ploy to show how simple using dry yeast can be.

I can't see how it would hurt. I've started making a starter even from the Wyeast smack packs, it's simple to do and I would rather ruin a batch of yeast than a batch of beer.