After making a starter, is any additional yeast required before pitching the starter into the wort?!
After making a starter, is any additional yeast required before pitching the starter into the wort?
So I made the mistake of briefly freezing my vial of white labs belgian wit, though only for a couple of hours. I was advised to make a starter to ensure the yeast was still okay and to at least wake it up if it was. I'm getting suspension and CO2. Is this enough to pitch into my wort or is there additional yeast needed? I just read something somewhere that confused me and it seemed like the starter, plus additional yeast was required? Or am I just okay pitching the starter? Even though this yeast seems fine in the starter, how can I be sure it will last long enough?
Answers:
The way you describe it, it sounds like you definitely have viable yeast. If you want, you can aerate your starter (sealing it securely and shaking good and violently) to help oxygenate it to help the yeast multiply and give it another 12 or so hours before pitching. You can use other methods to aerate if you like (and have the means), but shaking it will do the trick...just be sure to let the CO2 escape or you're not adding any oxygen. The sediment in your starter may simply be the portion of yeast cells that didn't survive the freezing. This isn't so bad, they'll actually serve as added nutrient for the surviving yeast cells.
Just remember, the purpose of the starter is to get the quantity of yeast you have now to multiply and establish a solid dominance over any other "bugs" in your wort. Oxygenation at the beginning is crucial to allow the aerobic multiplication of yeast. However, the reason you put an airlock on your fermenter is so that the yeast, when done consuming the oxygen and mulitplying, then turns to anaerobic fermentation and starts to convert your fernentable sugars to alcohol and CO2 (which, as you already know, needs to be let out). Further addition of oxygen at this point leads to stale flavors, yeast doing other things than anaerobic fermentation, and other hazards to be a possibility...particularly acetobacter taking hold and converting your alcohol to acetic acid...vinegar.
If it were up to me, I'd re-aerate your starter, let it sit for a few more hours, then pitch. You shouldn't need extra yeast.