To big of beer?

[kelsobrewer70]

Just made an Imperial stout. Calculated my OG and 1.078, but measured at 1.116. I used a 1 liter starter with white labs irish ale yeast. Should I just plan on doing another starter or just follow the fermentation and see where things go?

 

[Damoxemus]

Step up your starter if time allows or maybe pitch a packet of some dry yeast like Notty to help it along?

 

[JuanMoore]

That's a huge difference, so I'm guessing something with your volume or OG measurement is off.

Extract or all grain? If it was extract and you topped it off with water, I'm guessing the wort and water weren't mixed thoroughly, and you got a bad hydrometer reading (it's much more difficult to fully mix the water and wort than you'd think).

Also, have you calibrated your hydrometer recently? Sometimes the paper inside can slip, causing the readings to be off.

 

[WoodlandBrew]

Measuring the wort when it is hot and trying to compensate for temperature can also cause this kind of false reading. If you post your recipe it may give some further incite as to what may be amiss.

A 1 liter starter will produce about 200 billion cells, and you really want 250-300 billion. You might consider pitching what you have into 3 gallons of your wort and then adding the rest a day later. You just need to make sure the second part of wort stays sanitary.

For details see my book or blog:
http://woodlandbrew.blogspot.com/2012/12/no-more-wasteful-yeast-starters.html

 

[kelsobrewer70]

Recipe Type: Extract
Yeast: White Labs Irish Ale
Yeast Starter: none
Additional Yeast or Yeast Starter: none
Batch Size (Gallons): 5
Original Gravity: 1.099
Final Gravity: 1.028
IBU: 25
Boiling Time (Minutes): 60
Color: 42 SRM
Primary Fermentation (# of Days & Temp): 8-10 days at 65-70
Additional Fermentation: bottle condition for 10-14 days
Secondary Fermentation (# of Days & Temp): 5-7 at same
Tasting Notes: Great Tasting Beer. The brown sugar helps to bring out the chocolate tones.

6.6lbs dark syrup malt
3lbs dark DME
1/4lb black patent
1/2lb crystal
1/4lb chocolate malt
1/2lb roasted barley
1lb Dark Brown Sugar
1oz Challenger hops (60min boil)
1oz Cascade hops (30min boil)
1oz Cascade hops (15min boil)
1/4tsp Irish moss
Irish ale yeast (White Labs) or equivalent

I have already put everything into the primary and pitched with the 1 liter starter. I thought it was mixed well enough, but that could be the problem.

 

[JuanMoore]

When brewing extract you're adding a known amount of sugar to a known volume of water, so unless your end volume is way off, there's really no way the OG can be off by very much. I don't know how you calculated an OG of 1.078, or how the creator of the recipe calculated an OG of 1.099, but by my estimates you should have had an OG of 1.085 with those ingredients in a 5 gal batch. I would simply assume that's what your OG is since something obviously went wrong with your measurement.

To answer your original question, it depends on what the pitching rate actually was, and how long ago the yeast was pitched. With only a 1L starter and an OG of 1.085 you definitely underpitched, but there's likely enough yeast that it should still ferment out ok, and adding more yeast after fermentation has already started may not help things any. Hard to say what your actual pitching rate was without knowing the yeast manufacture date and whether the starter was shaken or put on a stir plate. For future reference, you can use pitching calculators to estimate how many cells are still alive in your liquid yeast culture, and what size starter you need to reach optimum pitching rates. Here's the one I use-
http://yeastcalc.com/

If the yeast was just pitched, and you didn't use a stir plate or the yeast was older, I'd buy another vial of yeast and pitch it. If fermentation has already started, or if the yeast was fresh and you used a stir plate, then I'd just let it ride and see what happens.