Wyeast 1010 Under Pitched?

[thorHB]

I know I under pitched the wheat ale that I have in the primary. Batch volume was 5.75 gal with OG 1.050. I pitched one Wyeast 1010 smack pack. Yeastcalc tells me that needed about 200B cells. Assuming good viability, I pitched about half of that. I did oxygenate with pure O which should have helped with reproduction. The fermentation was vigorous at first and a large krausen formed. 11 days later it is still slowly chugging along. Slight estery smell from the airlock but nothing crazy.

My question is this. Should I be making a starter every time I use liquid yeast? Is there a rule of thumb that you guys use where anything over 1.0XX OG you make a starter? What kind of growth can you expect from thorough oxygenation alone?

 

[Qhrumphf]

I use either Mr. Malty or YeastCalc, depending on my application. For simple single pack/vial stir plate starters, either works, but I prefer to use YeastCalc because it provides more information. For repitching, I use Mr. Malty's slurry guidelines. For stepped starters, or starters where I'm starting with an abnormal cell count, it'll either be YeastCalc, or a combination of both.

And then I target specific pitching rates. Both calculators base themselves on pitching rates of 0.75 million cells per milliliter of wort per degree Plato for ales, and then 1.5 mil cells/ml/°P for lagers (ie twice as much yeast), and then 1 mil cells/ml/°P for hybrids. There's nothing wrong with those rates, and they provide great results, but I stray a bit from them. For lagers, I follow that rate. For most American ales, I do as well. For English and Belgian ales, and Weizens (ie yeast-forward beers), I prefer a smaller pitching rate (0.5 mil/ml/°P), and for cleaner ales (Scottish ales, and very clean American ales) and hybrids, I like 1-1.2 mil/ml/°P, which is actually a little bit higher than the suggested rates. For very high gravity beers, I'd pitch at a slightly higher rate as well.

So, point here is that depending on your batch size, wort gravity, and age of yeast, you may not need a starter, but generally yes, with liquid yeast, you need a starter. For very small English or Belgian beers, I sometimes even let yeast get a bit older if it's super fresh. However, with even a low gravity Scottish Ale, a small starter may still be needed. However, I find it worth my while to often skip the starter, and instead make a session beer that doesn't need the starter, and then repitch from that into bigger beers.

In your case, assuming your pack was fairly fresh, it's not the end of the world. The pure O2 probably helped, but you'd have more esters than you would otherwise. I wouldn't try to repitch from that yeast, but it should still be fine.

 

[thorHB]

Thanks for such a detailed answer. Lots of good information. This is my second batch and there is obviously so much to learn. I'll be brewing an india red ale this weekend and will most definitely be making a starter now that I finally got my stir plate to stop throwing the bar.