Second Pale Ale - Missed OG

[DarkPhyre]

My first Pale ale is listed here. It is still in its secondary bottle. About 2 more weeks left in there.

I wanted to do a second Pale Ale following the same recipe and change one variable. In this case I changed the 5min hop addition from .2 to .5 and the flame out from .2 to .5 (ounces)

The Mash temp was 155 - where as before it was 152. The strike water was almost the same 1 degree different (from previous brew)

We had to run to home depot to get a replacement tube for the auto siphon as it still wasn't working right. - This started the problem. By the time we got back we started the strike water. So the total time of the mash was approx 2 hours. Before it was about 1 hour 15 min (from strike and sparge x2)

I took a pH reading of the mash out and it was at 5.4. I don't know what it was last brew.

We failed to get an OG reading (late and tired) but we did remember after we moved it into the carboy.

We used the carboy from my first brew that still had the yeast cake in it. (with a little amount of beer - we transferred the beer to secondary then about 3 hours later moved the new beer into that carboy)
Could all that yeast cause false gravity readings? what else could of caused us to be off by 8/10 points?

tl;dr

I used the bottle from my last brew's primary for new brew (3 hours old) mixed the crap out of the wort and then took a gravity reading, does that affect the reading?

does a 2 hour mash affect gravity? - negatively?

Would .6oz extra hops affect gravity?

I am off by 8/10 points from last brew

Thanks for input guys!!

 

[Faseel]

Ok few more questions, how long was your boil compared to the last one? Why did you mash higher? Do you know your waters alkalinity (total)?

 

[Faseel]

Some direct answers, mashing for 2 hours should not have a negative affect at all, as long as ph and temp are where they need to be. Such a small amount of hops would not affect O.G. also re-pitching off the old cake is cool, but I personally would do it as son as possible. ( start cooling your wort and then rack off 1st batch leaving that juicy cake ready to use within a half hour or so.

 

[temptnmonkey]

I'm not an expert, but as far as I know, gravity readings are only affected by things dissolved into solution. So yeast and hops should not affect your gravity readings.

 

[DarkPhyre]

Ok few more questions, how long was your boil compared to the last one? Why did you mash higher? Do you know your waters alkalinity (total)?

same with approx ~5 min variance.

I believe it was supposed to be 154. we were light last time and corrected it.

alkalinity before or after?
the wort was 5.4 But before I didn't check either brew.

 

[Faseel]

Ok your ph is good and my question about alkalinity was more about your finished product. Ok well, hmm, how accurate is your ph readings? Strips or meter?

 

[Faseel]

Ok a few things, if you take no ph corrective. Action at the start of the mash. Take a reading 15 minutes into it to make sure it is not rising. Do you test for completed conversion with iodine?

 

[gr8shandini]

Unless you're way off, pH isn't much of a factor in determining efficiency. The biggest single factor is usually the crush of the grain. Did you get it from the same supplier / LHBS? If not, that's probably your problem right there. Stick with the same supplier until you can get your own grain mill.

Also, what kind of sparging are you doing? if you're batch sparging, I find that insufficient stirring will cause a pretty big efficiency hit. I try to stir vigorously for 3 to 5 minutes to ensure that you're rinsing the grain as well as possible. I don't fly sparge, so someone else might want to give some tips and tricks if you're going that route.

 

[DarkPhyre]

All grains came from LHBS, all crushed same day as brew. It was a batch sparge. I didn't stir for 5 minutes but I did give it a hardy 30 second stir (I wasn't making friends w/the mash)
I did not test completed conversion w/iodine. and I used test strips.

 

[DarkPhyre]

I figured out what I did wrong.
I didn't account for the tare of the scale. so I was missing one pound of pale malt.

 

[Faseel]

D'oh! Oh well lesson learned fyi, there is probably a million thread debate on this, but if you ever feel batch isn't working out for you go with fly sparging my efficiency went up 15%.

 

[DarkPhyre]

well, I didn't know the OG until after we cooled it.

But I may look into that.