New to yeast starters

[cathlabrob]

Hi all, I’m starting a yeast starter for a 5 gal Octoberfest after watching a few online videos. I’m using 2 cups water to 1/2 cup DME. My question is: How long should you let it grow before pitching into the Octoberfest wort. I’m trying to plan the starter to the brew day. Thank you for any information since the videos didn’t touch on this.
‘sincerely,
Rob

 

[NTexBrewer]

If you are using a stir plate it will take anywhere from 24 to 36 hours for the starter to be complete. The starter will go from looking golden or amber to a creamy white as the yeast grows. You will also notice a small krausen (depending on yeast strain) and CO2 bubble gasing off along the edge of the starter and in the vortex. For some yeast strains, I’ve had the starter completely gas off and be done in 24 hours. Others after 36 hours it will still have a krausen and gasing off and I let it spin a little longer. I then cold crash the yeast for at least 24 hours but like to cold crash longer if the yeast strain does not flocculate well. On brew day, take the starter out of the fridge, decant most of the liquid and let it warm up to pitching temperature. Swirl and add to the beer. Some yeast strains like to stick to the bottom so you can add some chilled wort to help swirl it out. I have a plate chiller so I’ll sometimes run some chilled wort into my decanted starter and spin that while I’m filing the fermenter.

So if I’m planning to brew on a Saturday or Sunday I usually make my starter Monday evening. I figure by Tuesday evening or Wednesday Morning I can cold crash the starter. If the starter is not finished and I cold crash Wednesday or Thursday morning, I still have a few days to cold crash before the weekend.

 

[jdauria]

What yeast are you using? What's your recipe starting gravity estimate? Liquid or dry yeast? What's the date on the yeast pack? All those factor into how much yeast you need for a starter. If you are using lager yeast, which I assume you are, unless you are making a Mocktoberfest...1/2 cup, or 4 oz of DME in 2 cups (16 oz or .907 liters) would not be enough for a lager yeast. Lager yeast needs at least 3x the amount of yeast ale does. Not knowing any of those questions, assuming 1.050 OG and yeast was packaged today, and you are using a stir plate. per Brewer's Friend Yeast Calculator, using the base lager rate of 1.5, you would need to build 352 billion cells and again assuming 1.050 and yeast date of today...your starter would only give you 269 billion cells. The older the yeast and the higher your gravity, the difference between what you are building in starter vs what you need will grow. No stir plate with out shaking every now and then, then you only will build 145 billion cells, shaking the starter = 195 billion.

So I suggest you plug all your info into a starter calculator. Yeast Pitch Rate and Starter Calculator - Brewer's Friend

 

[cathlabrob]

Thank you to both of you. You both provided the missing info the video’s didn’t. Wish me luck, I will make the starter tonight and brew this weekend.