Did I under pitch?

I may just be paranoid... But, I've done some reading that I probably should have done before I actually brewed this high gravity beer. I've not really ever made one this big. Anyway, I'm making a Russian Imperial Stout with an OG of 1.086. I pitched a single Wyeast smack pack for my 5 gallon batch. After doing some reading about big beers I realized that I probably should have made a starter. After reading some other threads on here, I've realized I should always make a starter...live and learn, right? I have also learned that I should pay more attention to how much I pitch in relation to my OG. Having learned all of this I'm super paranoid that this beer is not going to finish out as it should and be way too sweet. My question is, if it doesn't finish, is it ruined or can I make a starter and pitch more yeast? Thanks for the help.

There's always the option of pitching more yeast, sure. You'll just have to see what happens with the yeast already in there first.

Yes you underpitched. If you just pitched it in the last day I would go buy a couple more packs and put it in or you have a good chance of getting stuck and will have off flavors due to excessive yeast growth.

I would just follow up with some dry yeast such as US-05. A single smack pack is underpitching by about 2/3

Well, it was one week ago. So, should I wait or go ahead and do it now? If I pitch more sooner rather than later, will that decrease the chance of having off flavors?

The problem that people are trying to explain here and why it matters how long ago you pitched is to do with yeast propagation that takes place in the fermenter. You pitch your yeast and it consumes O2 (that you put in there? right?), nutrients and sugar, they get fat and multiply until all the O2 is gone. The yeast then start making alcohol for you. Making alcohol weakens the yeast and eventually they die or just aren't able to eat any more sugar or they are too weak to eat the more complex sugars.

So if you had only just pitched the yeast throwing more in there would allow the yeast to also consume more O2 and propagate out to the correct number to do the job. Now that the beer is probably close to finished fermenting (or as close as it will get given the low numbers you pitched) adding more yeast will only be a small amount compared to how many yeast cells are really need to finish the beer. So you say well I will re-aerate the beer.... the problem is adding o2 at this stage will cause the beer to be skunked by oxidation as the yeast may not clean up all the extra O2 you add.

So if your beer does get stuck you can (it may not lots of people underpitch and the beer finishes)

A) raise temp and swirl to try to convince the yeast to finish the job (first option raising temps even up into the mid 70s late in the brew does not have a large impact of the flavors as they are mostly created during the propagation phase)

B) pitch a truck load more yeast two or three packs of dry yeast (rehydrated all the alcohol in the wort will kill a large % of the yeast as they are rehydrating in the wort)

C) Pitch on to a cake of similar yeast. (best option and a good excuse to brew another beer so quickly, pick a lighter beer, in terms of alcohol content and hops/malt)

In future use Mr Malty to calculate your pitch rates, it is a great tool and is free for homebrewers.

Clem

Wow, Clem. Thank you. We'll hope that it finishes... If not, I shall brew again!