Problems reaching right attenuation

I have tried making some higher gravity ales recently, and I've had trouble getting the right attenuation out of it. Both were IPAs with OGs around 1.060 (I'm on vacation and don't have my notes with me), and final attenuation was around 55%. Both were extract kits, and are supposed to be around 70%. What am I doing wrong? Is it an oxygenation problem?

Several questions (if you can remember)...

Which kit was it?

Which yeast did you use? WLP#xxx?

What malt did you have in the kit?

What temp did you ferment at?

it could indeed be an oxygen issue...a lack of it.

Bobby is doing an experiment right now, and he expects the results to prove that under-aerated beer has less lag time, but produces less attenuation since your yeast colony never grows very large and expends a lot of energy during that growth phase.

high oxygen levels means more lag time as the yeast uses all available O2 for growth, then goes gangbusters on the fermentable sugars.

beyond that, we need you to answer all of HB_99's questions. In particular, if Dry Malt was used and if so what brand name?

also 1.060 isn't terribly high...yeast shouldn't have a problem with that starting gravity if everything else is at optimal levels (oxygen, pitch rate, pitch temp, etc)

Right...but attentuation is a function of the yeast on the malt. Of course the amount of oxygen is important in that process. The more yeast cells you pitch the better. Do you have a stirplate? They really help your starters.

Some malts have a large amount of unfermentables (Briess) versus Munton's. I don't ever use Briess DME, but I've steeped their grains. I also don't use canned malt (LME).

Temperature is also an important factor. Ales like warmer temps while lager like cooler temps.

With an OG of 1.060 your FG should be in the neighborhood of 1.015.

I just answered in this thread. https://www.homebrewtalk.com/showthread.php?t=49079

Though the answer applies more to AG brewing, it may also be helpful for extract brewers.

Kai

I used NB's Three Hearted Ale extract kit for the IPA. Here are the ingredients

* 1 lbs. Briess Caramel 40
* 9.15 lbs. Gold Malt Syrup

* 1 oz. Centennial (60 min)
* 1 oz. Centennial (20 min)
* 2 oz. Centennial (5 min)
* 1 oz. Centennial Hops (dry hop)

* Wyeast #1084 Irish Ale Yeast.

and if I recall correctly, I fermented at 68º.

I aerated by aggressively stirring with a spoon. I stirred the wort and top-off water.

And I also think that my OG was around 1.060. I have this problem of my OG being low. I recently learned it was because I use top-off water.

Its not that your OG is actually low, its that your top off water isn't mixed in well enough, so your OG reading is simply skewed by being diluted. fermentation will mix it up.

if the recipe states an OG, use that. you really cannot miss OG with an extract brew, unless you top off to more than 5 gallons of final volume.

True, you may not have blended you brew and top off water enough.

Comments on your hop additions:

* 1 oz. Centennial (60 min) seems OK.

These hops make your brew flowery:

* 1 oz. Centennial (20 min)

These are for aroma:

* 2 oz. Centennial (5 min)
* 1 oz. Centennial Hops (dry hop)

It's all about the flavor of these hops at these times. They do not add bitterness at all.