How much will crystal malt effect FG?

[Oscbert]

I brewed a batch that I have brewed before. This time I added a 1/2 lb of crystal 40.
First time my FG was 1.011. I just did an FG reading on my second batch with the crystal and it was 1.020. I'm going to let it sit a few days longer at 70 degrees, but I think it might be done.

Would adding 1/2 lb of crystal 40 effect the FG that much or did my yeast not fully attenuate?

 

[BrewerinBR]

Crystal 40 will add a caramel sweetness and some dextrins so it is possible you got more unfermentable sugars. Need a lot more information to really know if the crystal 40 was the reason. Full recipe, mash temp, fermentation time and so forth.

 

[cmybeer]

9 points seems pretty high for a 1/5lb of Crystal 40. Seems like a yeast, mash or temp issue to me.

 

[Oscbert]

Sorry it took awhile to get back. Here are the details.

8 lbs Marris Otter
1/2 lb Aromatic Malt
1/2 lb Special Roast
1/4 lb Special Roast
1/2 lb Crystal 40

1 oz EKG for 60 min
.5 oz EKG 20 min
.5 oz EKG flameout

Wyyeast 1968 London ESB (I made a starter with 2000 ML of wort. Let it go for two days on a stir plate)

Mash temp was 151-150

My OG ended up being 1.048

It has been fermenting at 66 degrees for 14 days.

 

[hector]

I have a similar problem with my Recipe and I posted a thread in another section of HBT .

I think crystal malt reduces the attenuation and I'd like to know what would be a prefiguration of the F.G. .

Hector