Will one packet be enough to ferment out a 5.5gal batch of 1.063 ale, if the packet is less than 6 months old? Just curious.
Volume is missing, assumeing a 5 gal batch you should be fine.
+1
I have used year old S05 in medium strength ales with success. You should be fine.
Be sure to rehydrate it for maximum performance. Cheers!!!
Now see… If I had said you’ll be fine the dialogue would have been “starter”. 
Rehydrate.
How exactly does rehydrating dry yeast maximize its performance? I’ve always understood rehydrating dry yeast to be largely unnecessary. I’m talking about yeast that you know has normal viability.
Per Clayton Cone at Lallemand, yeast can’t exhibit selective permeability of the cell wall during rehydration. So when rehydrating in wort, all of the compounds in the wort will enter the cells. That kills some (possibly as many as half) of them outright, and can result in reduced health in the survivors.
Without rehydrating approximately 1/2 the yeast will die as they rehydrate, at least that’s the ROT number as I understand it.
IMHO you are on the borderline between needing to rehydrate or not. Otherwise I would have mentioned it.
Additional reading regarding what Dr. Clayton Cone has said about rehydration:
Quote:
Let me give you some facts regarding rehydration and you can decide for
yourself where you want to compromise.
Every strain of yeast has its own optimum rehydration temperature. All of
them range between 95 F to 105F. Most of them closer to 105F. The dried
yeast cell wall is fragile and it is the first few minutes (possibly
seconds) of rehydration that the warm temperature is critical while it is
reconstituting its cell wall structure.
As you drop the initial temperature of the water from 95 to 85 or 75 or 65F
the yeast leached out more and more of its insides damaging the each cell.
The yeast viability also drops proportionally. At 95 – 105 F, there is
100% recovery of the viable dry yeast. At 60F, there can be as much as 60%
dead cells.
The water should be tap water with the normal amount of hardness present.
The hardness is essential for good recovery. 250 -500 ppm hardness is
ideal. This means that deionized or distilled water should not be used.
Ideally, the warm rehydration water should contain about 0.5 – 1.0% yeast
extract
For the initial few minutes (perhaps seconds) of rehydration, the yeast
cell wall cannot differentiate what passes through the wall. Toxic
materials like sprays, hops, SO2 and sugars in high levels, that the yeast
normally can selectively keep from passing through its cell wall rush right
in and seriously damage the cells. The moment that the cell wall is
properly reconstituted, the yeast can then regulate what goes in and out of
the cell. That is why we hesitate to recommend rehydration in wort or
must. Very dilute wort seems to be OK.
We recommend that the rehydrated yeast be added to the wort within 30
minutes. We have built into each cell a large amount of glycogen and
trehalose that give the yeast a burst of energy to kick off the growth
cycle when it is in the wort. It is quickly used up if the yeast is
rehydrated for more than 30 minutes. There is no damage done here if it is
not immediatly add to the wort. You just do not get the added benefit of
that sudden burst of energy. We also recommend that you attemperate the
rehydrated yeast to with in 15F of the wort before adding to the wort.
Warm yeast into a cold wort will cause many of the yeast to produce petite
mutants that will never grow or ferment properly and will cause them to
produce H2S. The attemperation can take place over a very brief period by
adding, in encrements, a small amount of the cooler wort to the rehydrated
yeast.
Many times we find that warm water is added to a very cold container that
drops the rehydrating water below the desired temperature.
Sometimes refrigerated, very cold, dry yeast is added directly to the warm
water with out giving it time to come to room temperature. The initial
water intering the cell is then cool.
How do many beer and wine makers have successful fermentations when they
ignore all the above? I believe that it is just a numbers game. Each gram
of Active Dry Yeast contains about 20 billion live yeast cells. If you
slightly damage the cells, they have a remarkable ability to recover in the
rich wort. If you kill 60% of the cell you still have 8 billion cells per
gram that can go on to do the job at a slower rate.
The manufacturer of Active Dry Beer Yeast would be remiss if they offered
rehydration instructions that were less than the very best that their data
indicated.
One very important factor that the distributor and beer maker should keep
in mind is that Active Dry Yeast is dormant or inactive and not inert, so
keep refrigerated at all times. Do not store in a tin roofed warehouse
that becomes an oven or on a window sill that gets equally hot.
Active Dry Yeast looses about 20% of its activity in a year when it is
stored at 75 F and only 4% when refrigerated.
The above overview of rehydration should tell you that there is a very best
way to rehydrate. It should also tell you where you are safe in adapting
the rehydration procedure to fit your clients.
Clayton Cone.
End Quote
I pitch without rehydration in wort up to the mid-upper 70s OG. I’ve never had any problems. Maybe rehydration would be better, but I can’t imagine why based on experience. My guess is that there are so many cells it really doesn’t matter if I kill some off.
Actually 1.080 is my cut off, EVERYTHING over that get rehydrated, very little under.
I recently made a 1.112 Barleywine that was dry pitched and it came out of the fermenter tasting like really fine.
Fred…after hearing you say your cut off was 1.080 I was thinking “oh shit” but it tasted great. It’s in the secondary conditioning for a few months right now.
At 1.112 I rehydrate 2 packs, But you noticed how adaptable those little critters are.
<1.080 1 pack sprinkled
1.080+ 1 pack rehydrated
1.100+ 2 packs rehydrated
1.120+ 3 packs rehydrated.
More important on big beers is the fermentation temp.
I started rehydrating, but only because it makes me feel better. Have to agree with Denny that I really haven’t seen any “real world” difference.
Thanks for posting Clayton Cone’s comments. Nice to have info from the experts–the reasoning seems sound.
I agree that the reasoning is sound. I just can’t agree that it makes much difference.
I am sure that Denny wouldn’t make a statement of fact without a rigourous triangle test!
Yes…I used 2 packs in the 1.112 BW.
I just sprinkled it on and the next morning it was off to the races.
The aroma out of the airlock on the second day was mesmerizing. 
Two or three years ago I actually did do a couple batches side by side and have to admit the rehydrated one took off faster. Can’t say I could really tell a difference in the finished beer though.
I can’t find it right now, but the instructions on the Lallemand website say to use water at 70F. I guess that’s wrong. I’ll try the higher temp next time. Thanks for that Clayton Cone info. It really helps clarify things.