How much yeast needed?

I plan on doing a IPA with a OG of 1.091 and will use Safale US-05 dry which I will re-hydrate before pitching. My question is with a gravity that high will a single packet of 05 be enough? I plan to ferment at 62-65f (unless someone thinks hotter will be better on this). I also plan to aerate by mixing in my carboy for about 10 minutes before I pitch, might even agitate it a little after a few days.

I have also read that some others start out much warmer for a few days then cool it down afterwards, which I can easily do if that would be the best bet.

*edit* This is extract (will start my all-grain after this batch woo!) and this is essentially 10.15 lbs of gold malt syrup and I will pitch at about 72f.

The Mr Malty Yeast Pitch Calculator is an invaluable tool to use for this sort of thing. It works for liquid and for dry.

As a rule of thumb some people use (including me), 1.060-1.100 should get 2 packs. At 1.091, it'll likely stress the yeast and have a stalled fermentation. You should also pitch at the temp you're going to ferment at, since the yeast develops its' character very early on. If you pitch at 75 or 80, it'll develop the characteristics for that, and you'll likely get a lot of off-flavors (as well as a headache from drinking all that fusel alcohol).

5 gallons, I assume? Use 2 packs of yeast for such high gravity. I would use 2 packs for anything over roughly 1.080.

Pitch cool, low 60s or same as your regular ferment temperature. Don't ever ferment above 70 F unless maybe you're making a saison, and even then, totally unnecessary in my experience.

Yeah, 5 gallon. Well, looks like I will need to go grab another darn 05 then, I would rather spend the time + money to do it right instead of chance it. Thanks guys, I'll have to post how this one turns out. My current batch is in the 2nd carboy now, it was a 1.075 OG, but I used a Wyeast 1968 London liquid on it, and actually had issues with it not starting (I did not arate it enough evidently and I had to shake it up to wake it up ;P )

Definitely grab another pack. One good thing about US-05 is that it's pretty inexpensive, so there's not much to lose by adding a double dose.

I'm doing the blood orange Hefe/wheat I came across in the recipe thread. I have a feeling I need to pitch another packet of yeast. My OG reading was 1.080 and after pitching Wyeast German ale 1007 smack pack at ~10:40 last night I haven't seen any signs of fermentation. From what I read it should be going nuts. After the initial vigorous fermentation, the recipe calls for addition of lemonade/syrup and Wyeast 3333. My question is should I pitch a second wyeast 1007 pack now and the 3333 later? I'm doing a 5 gallon partial mash batch for reference. Attached is the grain bill and hop schedule.

Here is my modified version of the recipe

HOME BREW RECIPE:
Title: Blood Orange Hefe

Brew Method: Partial Mash
Style Name: Weizen/Weissbier
Boil Time: 60 min
Batch Size: 5 gallons (fermentor volume)
Boil Size: 3 gallons
Efficiency: 75% (brew house)

STATS:
Original Gravity: 1.080
Final Gravity: 1.018
ABV (standard): 7.25%

FERMENTABLES:
3 lb - American - White Wheat
0.5 lb - American - Vienna
0.175 lb - German - Acidulated Malt
4.25 lb - Liquid Malt Extract - Extra Light
1.82 lb - Liquid Malt Extract- Extra Light
0.85 lb - Light Brown Sugar

HOPS:
0.25 oz - Cascade, Type: Pellet, AA: 7, Use: Boil for 60 min
0.25 oz - Sorachi Ace, Type: Pellet, AA: 11.1, Use: Boil for 20 min
0.25 oz - Cascade, Type: Pellet, AA: 7, Use: Boil for 20 min
0.25 oz - Sorachi Ace, Type: Pellet, AA: 11.1, Use: Boil for 7 min

MASH GUIDELINES:
1) Temp: 158 F, Time: 45 min, Amount: 4.375 qt

OTHER INGREDIENTS:
0.5 oz - Orange Zest, Time: 5 min, Type: Other, Use: Boil

YEAST:
Wyeast - German Ale 1007
Starter: No
Form: Liquid
Attenuation (avg): 75%
Flocculation: Low
Optimum Temp: 55 - 68 F
Fermentation Temp: 62-66 F
Pitch Rate: 1.0 (M cells / ml / deg P)

Water Notes:
-Distilled or RO water
-Use just over 1/4 tsp of calcium chloride in mash, then add another 3/4 teaspoon at beginning of boil.

NOTES:
***3rd DAY ADDITIONS***
Blood Orangeade:
1 x 1.75 liter of Simply Lemonade mixed with 8 to 9 ounces of Torani Blood Orange Extract, sample to see if you like the flavor before adding....add after 3 to 4 days of vigorous fermentation has ended, also dont forget to add Wyeast 3333 at this time, blow off tube recommended.
-No Secondary, Just ferment completely and bottle.

I had a slow start due to my temps being a tad too low (lower than what I pitched at) and also I did not oxinate it enough. You make sure you did both of those really well? If not go give that a damn good shake to wake up the yeast.

BobOki said:

I had a slow start due to my temps being a tad too low (lower than what I pitched at) and also I did not oxinate it enough. You make sure you did both of those really well? If not go give that a damn good shake to wake up the yeast.

Click to expand...

So the amount of yeast (1 smack pack) doesn't matter with that high of an OG(1.080)?

BobOki said:

I had a slow start due to my temps being a tad too low (lower than what I pitched at) and also I did not oxinate it enough. You make sure you did both of those really well? If not go give that a damn good shake to wake up the yeast.

Click to expand...

Actually, I just took a peek inside the blowoff hole and low and behold there is about an inch or two of fluffy white Krausen and at 64°F which is about where I pitched. Thanks for the reply. This is definately going to be a test of patience since it's my first PM and my first non-mr beer brew. I do a secondary in about 4 days, so I may fix up a starter of wyeast 1007 and cut it in half to pitch with the 3333, just so it doesn't stress the yeast.

lumpher said:

As a rule of thumb some people use (including me), 1.060-1.100 should get 2 packs. At 1.091, it'll likely stress the yeast and have a stalled fermentation. You should also pitch at the temp you're going to ferment at, since the yeast develops its' character very early on. If you pitch at 75 or 80, it'll develop the characteristics for that, and you'll likely get a lot of off-flavors (as well as a headache from drinking all that fusel alcohol).

Click to expand...

Are you sure about the pitch temp? The Fermentis website says to rehydrate in 80 degree water for 30 minutes. Is this information out dated?

And no, I am being told form y 1.09 I will need more yeast, but it sounds like you already have more yeast that you are going to be using. 75-80 sounds a little high though.