Re-Pitch ?

[armymedic942]

I brewed an AG american IPA last weekend. The final brew volume ended up at around 7 gal with an OG of 1.055. I'm an AG noob, and ended up under pitching with a single pack of wyeast 1272 (American Ale II smack pack).
Pitch temp was 65, and I had really good fermentation activity within 12 hours. As of yesterday it appears that most of the primary activity has stopped. I took a gravity reading and its at 1.020. to be honest that is pretty good considering...but i would like to get to a FG of 1.012.

should I re-pitch, leave in the primary or move to a secondary? can i expect the gravity to drop during secondary fermentation?

 

[kh54s10]

You should not move the beer to a secondary before you have reached final gravity. Secondary fermentation is a misnomer. It is more correctly described as a bright tank and is used to get the beer more clear. I would wait another week or two then take a gravity reading, wait another day. If they are the same then you have the final gravity that yeast will produce.

Was this an extract recipe? If so 1.020 is a gravity where extracts often finish for some reason. Pitching more yeast would be unlikely to do anything.

I suspect that you are just measuring too soon. Patience. The gravity might still be dropping.

I like to ferment in primary for 3 weeks then package the beer - no secondary.

 

[Hopper5000]

He said he brewed an AG beer so it's not extract.

If you take successive readings a couple days apart and it hasn't changed then it's done/stuck. For a beer that low in OG one smack pack was probably a decent amount of yeast but if you go by the calculators you probably should have done a but more. I personally make starters as it has greatly increased the quality of my brews.

Anyways, my question is what temp did you mash at? If you mashed on the higher range of the spectrum (154 to 158) then your beer probably is truely done fermenting. If not then you might want to pitch some more yeast or heat the brew up (what temp did it ferment at and where is it now?). First I would try heating it up to 70ish and see if it drops the gravity a bit more.

As far as primary I usually leave my beers for at least 2 weeks and sometimes 3 or 4.

 

[armymedic942]

No it was a 10gal all grain recipie .My biggest concern is it was my first all grain, and I only bought a single yeast pack not knowing it was only enough for 5 gal. I pitched at midnight, so i couldnt go out and buy another.
Luckily after my boil and a few pump issues, I ended up with a final volume of 7 gal, but it is still a big under pitch. I have been getting conflicting advice on whether to re-pitch or not.
So far the flavour is good, no off tastes...but I really want to keep this brew on track

 

[kh54s10]

Oh, DUH! I actually saw the AG at first . Then got off track.?!?

 

[armymedic942]

I mashed at 158. Grain bill was 27 pounds using mostly canadian 2 row (22 lbs), with some munich, chocolate, cara, crystal, and brown malts making up the rest.
my pitch was 65, during the early ferm it rose to 70, and I had some trouble with my ferm chamber so it briefly went as high as 74, but i got it under control, so the average temp has been 69. the last 2 day it has settled to 66.

 

[Hopper5000]

Oh well if you actually mashed at 158 then the brew is done, even though you did under pitch. You created a lot of unfermentables with that mash temp. IMHO, it's probably done. Is it cloyingly sweet tight now or does it just have a nice solid mouth feel?

 

[BigFloyd]

Since you seriously under-pitched with one smack pack in 7 gallons of 1.055 wort mashed at 158*F be happy that you made it to 1.020. If it stays there for a few days, you may as well cold crash 4-5 days and then bottle.

Time to begin doing yeast starters or stick with multiple packs of dry yeast. A couple of packets of US-05 would have given you plenty of cells to do the job.

 

[kh54s10]

158 is pretty high for a mash temperature unless you are trying to get a strong malty/sweet flavor. It will produce more unfermentables.

I still feel you are measuring for final gravity too early. The gravity might drop some more. At this point, the yeast would have reproduced to sufficient cell counts, I don't think repitching is going to do anything. You might try swirling very gently to rouse some of the settled yeast into suspension and raise the temperature a little.

It might be done where it is or it might drop a couple of points. It will likely be higher FG than predicted.

 

[Hopper5000]

kh has a good point in that you should wait a bit longer until you do antyhing with it

 

[armymedic942]

Thanks for all the advice, I'm a bit confuse about the mash temp comments though. I am running an Electric HERMS system, so my mash temp is very controllable. The recipie called for 158 mash temp
as for mouth feel, it is actually very balanced. bitter citrusy finish ( i used citra, amarillo, centennial, and nelson sauvin)

 

[Hopper5000]

Well if that's what the recipe called for then that's what you should go for. Generally people mash in the 148-153 range. 148 to 150 will cause more fermentable wort (drier beer) because of the enzyme (beta amylase) that is activated will produce more fermentable sugars (maltose). 151 to 153 is a mix of both enzymes (alpha and beta) and this is generally where people mash because it's a good mix of both types of fermentable and non-fermentable sugars and won't leave your beer too dry. 154 to 158 is where alpha amylase is dominant and will produce more dextrins which aren't fermentable by beer yeast. This will leave a residual maltiness and mouth feel in the beer. Generally when making an ipa you want to accentuate the hops which is why people don't mash that high usually.

 

[Hopper5000]

You can read more about that stuff on the wiki on this websit too...