Yeast starter question...

[TimCA]

OK so I have been making yeast starters on a stir plate for years. Now I’m over analyzing and need input. So using the Mr. Malty calculator if it states that I need 1.8 L and 3 vile of yeast will my total starter be over 2L ? The 1.8 L of wort and the volume of yeast and liquid from the WL001. i.e. the recommended 1.8 L starter is in reality more like a 2.1 L starter.
Thanks
TimCA

[mordantly]

he means pitching 3 tubes into 1.8L to build up the counts... why not do a 3-step 10-fold build up from one tube?

[TimCA]

I would like to but haven’t don the math or thought it through. Can you give me a quick "recipe". I.E. do I pitched one tube into 250ml and stir plate for 24 hr, then decant and repeat in 500 ml then repeat in 750... How should it take to get from one tube to 540 billion cells? (11 G of 1.070 wort)

Thanks
Tim

[spiderwrangler]

Good rule of thumb is that 1 pack (at ~100 billion cells if fairly fresh) will double in a 2L starter. When you increase the amount of yeast you add to the starter, you get less growth. So 1 vial in 2L will give you 200 bil cells, while 2 vials in 2L will only give you ~300 bil. More total yeast, but lower growth factor.

[TimCA]

Thanks for the reply so what happens if I put 1 vile in 4000 ml. OR if I put 1 vile in 2000ML get the 200 bill cells. then would I chill, decant and add a new 2000 ml wort to get 400 bill cells or do I need to add more wort. Is there a "sepping up chart''? And what size stirr plate do you all have (IE Doc) to be running a 3 G starter, is it 110 v or 240???


Thanks
Tim

[gwk453]

I use a 3L flask for a 2.5 L starter w/stirplate and have blow out ferments with ales yeast using one vial or smackpack of yeast per 5 gal of beer. I stir 24 hours than chill, you don't want to go to zero activity before you chill down. Wait 24-48 hrs. before you decant. Some yeast doesn't drop to the bottom well. Some you can decant in 24 hrs, some take 48 hr. or more to settle. I seem to do a better job if I syphon with sanitized small air line tubing instead of moving the flask and decanting in the sink. I brew 12 gallon batchs so with one stir plate I have to start several days before I brew, with 2 starters to get ready. I use 1 pack or vials for lagers too, and have had no ferment problems if the yeast was fresh dated. Most of my beer is around 6 % alcohol. If I was going high alcohol, I would start with a 1 L starter than decant to a start a 2.5 L starter.
To complicate my brew day, after I boil my wort 5 minutes and before I add hops, I pull of 2 liters of wort. Cool the 2 L of wort to fermentation temp, while I susequently warm my chilled decanted wort to fermentation temp. I combine and place on a stir plate for 10 min each. This gives me a real aggressive ferment. I start drinking after the airlock are on the carboys. Yeast manufacturing websites can be a good source of stepping up info. I do have an excellant yeast book, too! The 3 L flask are great! I have used a 5 L and used 2 vials to make a 4 L starter, but I still remember the sickening cracking noise it made from too much heat too soon! Always start with lower heat before you ramp up your starter.

[spiderwrangler]

you don't want to go to zero activity before you chill down.

I seem to remember that letting it finish fermenting is better, as they yeast will build up glycogen and trehalose reserves before dropping dormant in a spent wort.

[gwk453]

I am not saying to put a chugging ferment into the chill. Your growth is usually done in 18 - 24 hrs. With a low gravity starter(1.035 -1.040), the sugars will be used. I don't sweat an occasional bubble. I usually rest my yeast a minimum of 12 hr before using to let them build their reserves up. What I do may not be based 100 % on scientific studies but my ferments are usually messy and violent . I have to start 5 days early with my consecutive starters setup, but I just got the parts to build a double stirpate this week so I can bite this dog in the ass. Strong yeast has really made my brew MUCH better! Thanks BN'ers