attenuation issues

[Jewsh]

I brewed a extract kit , A superior strong ale, almost two weeks ago.
The o.g. was right on at 1.070, I pitched rehydrated yeast , and it began fermenting witihin 10 hrs.
The temp reached as high as 81 , but I just let it go. It went very strong for two days then quit.
Me being the new homebrewer I am, checked the gravity (smart move I know).... It was at 1.030. So I left it. A week and a half later, after no action in the airlock, holding it between 63 and 68 degrees during that period.
I just checked the gravity and it was 1.026. That is a 62.2% attenuation.

Any thoughts on my process? Did the fermentation ramping up that high by itself kill off the yeast? should I pitch more yeast? Raise the temp a bit? Give it more time? It was a high gravity ale.
The sample I took tastes great, but does not have the body or alcohol content I expected!

Rock on!:rockin:

 

[Beernik]

My guess is that much temperature swing shocked the yeast and stuck the fermentation. You might be able to restarted it by warming the fermentor up. I've tried that method without much success. Pitching a new starter has worked for me.

 

[david_42]

What yeast? Re-pitching is a good idea.

 

[jessup]

if you only used one packet of dried yeast that may be the reason. as most of us, you severly underpitched yeast which is a typical mistake we all make. try adding another packet of yeast. when using dry yeast, they're so cheap you should buy a few to add all at once. use www.mrmalty.com to determine your proper pitching rates next time and you'll be shocked at how much yeast you should be using.

 

[Jewsh]

It was muttons dry ale yeast. so just open the packet and sprinkle it on top or rehydrate it? I have never made a starter, so therefore dont really know how to go about it!

 

[Beernik]

a quick and dirty starter: put 3oz of DME in 1 liter or a quart of water. Let the yeast work until the airlock stops bubbling, about 2 days. Swirl it to resuspend the yeast and pour it in the fermentor.

It's not the most efficient way, but it works.

 

[Jewsh]

Boiled water I presume? Wht is the deal with the stir plate? It keeps the yeast suspended.

 

[david_42]

Muntons dry is a low-attenuation yeast. It was selected for malt + sugar kits. Try Muntons Gold, Nottingham or S-05.

 

[Jewsh]

so I should repitch? I was planing on bottling sunday.

 

[Beernik]

I'm going to defer to D42. With that yeast, that might be all the attenuation you get. It's low-medium attenuating and it has difficulty with 100% malt fermentables. If you don't mind the higher FG, go a head and bottle this weekend.

If you want to drop the FG, do a starter with a better attenuating yeast strain. But it will probably take another two weeks to finish up.

The deal with the stir plate on starters is keeping yeast and sugars suspended so the yeast population can be maximized. I've made a lot of starters, I've never used a stir plate. But I do it knowing that I'm still underpitching for 5 gallons, but not by much.

 

[Jewsh]

Thanks for the advice. I will calculate my pitching rate from now on. This is such a fun and extremely interesting hobby!

 

[ChrisS68]

No need to do a starter with dry yeast. To repitch, sprinkle on top and it'll do its thing.