Consequences of over-pitching?

Are there any consequences for pitching yeast again after a couple of days of iffy fermentation besides extra yeast at the bottom of the bottle? Does sitting on more dead yeast cells than usual in the fermentor impart any off flavors that I should know about? Also, I'm using Wyeast 1968 London ESB, and I read in the NB catalog that this yeast may require additional agitation. What does this mean exactly? Thanks for any help!

John

I was wondering the same thing. There are a few kits that AHS sells that suggest double pitching yeast because of a high OG.

How much did you pitch? WE need more info. By agitation they mean that you might need to arouse the yeast if fermentation lags. You can do this by shaking the carboy or bucket to get the yeast back in suspension. Typically this is done if fermentation gets stuck. Once the Kraussen falls you can take a hydrometer reading to see how far it has dropped from your OG. You should get into the habit of aerating the cooled wort prior to pitching the yeast so the have lots of O2. You can achieve this several ways many of which are on this forum. Personally I inject O2 directly from a tank via an airstone.

I aerated prior to pitching the yeast once. I pitched a Wyeast 1968 London ESB smack pack, didn't have a hydrometer (something that I will refuse to do another batch without) so I'm not sure of the OG. So it's OK if I aerate again in a couple of days? I thought that oxygen was usually a bad thing during this stage, but I'd definitely give it a shot (although I won't until someone says go for it!). Thanks.

John

Do not aerate once fermentation has started! It will only cause bad things to happen. O2 is only beneficial before pitching

Well, that's mostly true. I've heard a few pros suggest that you can add oxygen for the first half of fermentation because the yeast will have the chance to consume it all. In the case of high ABV beers (15% and higher), you would continuously feed more sugar and oxygenate.

Wyeast 1968 is a highly flocculant strain, which means it drops out of suspension quickly.

There are pros and cons to this characteristic. On the plus side, it means star-bright beer without filtration or fining. On the minus, it often means it settles out before an appropriate terminal gravity is reached.

Post your recipe. We can guesstimate your OG from the grist. If you haven't bought an hydrometer yet, do so at once and take a gravity reading. Post that information also. Post the ambient temperature of the room where you're fermenting.

In the meantime, do nothing except gently rouse the yeast. If the beer is in a bucket, clean and sanitize a long, stainless-steel serving spoon and swirl the beer until you get clumps of yeast rising off the bottom and well mixed (avoid touching the sides and/or bottom of the plastic pail or you'll scratch and ruin it). If the beer is in a carboy, GENTLY rock the carboy to set up currents which will resuspend the yeast flocs. Note: Take your gravity before rousing.

Highly flocculant yeasts, like Wyeast 1968 and 1187 (Ringwood), should be slightly overpitched for best results. You, unfortunately, underpitched. You probably should have pitched more than twice the amount of yeast you pitched with that one XL smack-pack. (See the HBT Wiki article I wrote on pitching rates.)

That's why you had a sluggish ferment. It's probably still working, albeit slowly; it'll continue to work for a time.

BUT - do not pitch more yeast until we say so.

Cheers,

Bob

Thanks to everyone for the help! I'm gonna do all the things that you just suggested, NQ3X, and get back to you. Hopefully this beer will turn out awesome still!

Thanks again,

John

OK, so...

I went over and took a hydrometer reading, 1.010. The original gravity was supposed to be 1045, although I'm not sure what it actually came out to be because I did not have a hydrometer at the time. The grain bill is as follows-

Specialty Grains- 8oz. Simpson's Dark Crystal
2oz. Fawcett Pale Chocolate
DME- 3 lbs. Munton Light
1 lbs. Munton's Amber

I roused the yeast slightly after taking this reading by shifting the carboy around slightly. Temperature is probably around 65, and I'm thinking that this is an OK gravity to be at at this point (brewed on 11/24). Please let me know, though, and thanks again for all of the help.

Peace,
John

NQ3X- Read through your yeast pitching article. Good stuff, thanks!

My calculations show an OG of 1040 for 5 gallons. Note: Any brewing software will compute an OG with extract being the bulk of the fermentables. A given amount of extract in a given amount of water will always yield the same OG.

If you're now at 1010, you're done. That's 75% attenuation, which is within spec for 1968.

Yeast is funny. Not all strains act the same. Some will violently shoot froth through the airlock. Some won't make much of a krauesen at all. The fermentation characteristics of each strain are always slightly, often wildly, different.

I suspect your ferment wasn't iffy at all; I suspect it just went by fairly quickly. English ale yeasts, expecially when pitched in sufficient quantities, tend to make their biggest gravity drop in 24-36 hours from krauesen being observed. They might take a week after that to polish off those last few gravity points. Which is why you should still leave it alone for a few days - check the gravity again on Thursday. If it's still at 1010, it's well and truly done, andyou should be good to move it if you want.

Thanks for the kind words!

Bob