Another yeast starter Question

[Soko]

I completed a 1200mL extra light DME yeast starter 2 days ago using white labs 090 yeast and have been shaking intermediately. I am planning on pitching in about 24 hours into a OG of 1.084 We will also be adding another vial of WL 090

Now do I have enough time to either add more wort to the flask or possibly decant and step up the starter to increase the yeast count?

Also before pitching into our wort we will decant, does anybody add more wort before pitching to get the yeast going again?

Thanks for the help.....I love this forum.

 

[Hex23]

If you're going to decant, you need to wait for the yeast to finish then preferably crash cool to get the yeast to flocculate if they didn't already. Altogether that can take 3-7 days depending on the yeast and conditions.

You don't have to decant before a step-up. You could just add cooled wort and yeast to increase counts. I think your scenario is complicated enough (wanting to step up by adding wort and yeast) that you should gauge total cell count by looking at the volume of the yeast mass.

BTW, lots of great starter info here http://www.mrmalty.com/starter_faq.php and here http://www.mrmalty.com/calc/calc.html

 

[JBZSTL]

A few days ago I put together a yeast starter. After allowing the original starter to sit for 24 hours at room temperature I placed the flask in the refrigerator. I removed the flask after an additional 24 hours and this evening, after boiling the wort for 15 minutes, I decanted the original wort yield in the flask and added the boiled wort to the flask. Afterwards I realized that I believe I should have allowed the wort to cool prior to adding to the starter flask.

Should I have allowed the wort to cool prior to adding to the starter and if so what potential effects could this possible mistake have? What should I do to correct any mistakes that may have been made? I intend on brewing an Imperial IPA tomorrow, should I wait?

Great link for mr malty by the way. Very informative.

 

[Hex23]

So if I follow correctly you were adding boiled wort to step up the starter? If your wort was very hot (say above 110-120 F) you unfortunately probably killed the yeast. You'll have to start over. Even exposing yeast to anything more than 10 degrees different than its current temperature is not good practice. It's also a surprise that you didn't heat-shock the flask since it came right out of the refrigerator, right?

 

[JBZSTL]

So if I follow correctly you were adding boiled wort to step up the starter? If your wort was very hot (say above 90-100 F) you unfortunately probably killed the yeast. You'll have to start over. It's also a surprise that you didn't heat-shock the flask since it came right out of the refrigerator, right?

The flask had been out of the fridge for a few hours and was at or close to room temperature if I were to guess. Yes, the wort was very hot. Looks like I won't be brewing tomorrow night.

Thanks

 

[Hex23]

Sorry - edited my post a little bit. Turns out the temperature threshold is somewhat higher (like 130-140F for instant death), but it sounds like your wort was hotter than that.

If you really need to brew tomorrow and have a brew shop nearby, you could just buy multiple vials/packs of yeast instead of the starter, and just miss out on the extra insurance of yeast health that a starter provides. Or depending on the style, you could switch to a dry yeast. There's always next time to get your starter right.

 

[JBZSTL]

Sorry - edited my post a little bit. Turns out the temperature threshold is somewhat higher (like 130-140F for instant death), but it sounds like your wort was hotter than that.

If you really need to brew tomorrow and have a brew shop nearby, you could just buy multiple vials/packs of yeast instead of the starter, and just miss out on the extra insurance of yeast health that a starter provides. Or depending on the style, you could switch to a dry yeast. There's always next time to get your starter right.

Thanks for the insight. There appeared to be signs of activity this morning but I'm not going to chance it. I'll just pitch two smack packs. Unfortunately the closest LHBS is 45 minutes round trip. I sit in the middle of two different LHBS.