Yeast Starter

[Hasa]

Just a quick question, I made a 2.5L yeast starter from two CPA stubbies with 250g of BE2. What I want to know is - how do I know when it's ready to add to the wort? There doesn't seem to be much yeast that has flocculated, and it has been kept at about 20degC for about 36 hours. No noticeable krausen or airlock activity.

Am I worrying about nothing? I was going to add it to my brew some time late Monday afternoon, but if you think I should wait, any advice would be welcome

 

[BoilerBoy]

I'd pitching another yeast for this brew, next time try using only 100-200ml of starter wort and wait for signs of activity (this could take 24-48 hours) then step up your starter by adding another litre of starter wort and let it ferment out.

Two stubbies worth of inactive yeast in 2.5L starter wort is way too much for the yeast to cope with initially.

Cheers,
BB

 

[Supra-Jim]

CPA yeast cultures can take a few days (see longer than 36 hours) to get going. Be patient!

A couple of pointers for future starters.
1. Ditch the air lock, and use a piece of santised al foil pressed over your starter vessel lid (assuming your using a flask or a juice bottle??) It does not need to be air tight, just pressed on so that nothing can drop in, but the CO2 can escape easily.

2. Shake it a lot. Everything you walk past your starter give it a little shake. This will help keep the yeast suspended in the starter and also drive off/release any CO2 that has been created by the yeast (for healthy growth in starters you want to remove as much co2 as you can). So shake often!!

3. Don't use BE2 for starters. Whilst nothing overly bad or wrong with it. You can make a better starter with just some LDME (same ratios you used above). It'll save you a bit of money too.

4. Krausen is not necessarily a sign of yeast growth, it can be a visual sign of fermentation. You're building a starter, you want growth not fermentation, don't be worried if you don't see one. Want you want to see is Co2 bubbles in your starter (when you shake it!) and increasing yeast in the bottom of your starter vessel (shake it back in to solution!).

5. Don't know what your brew size is but 2.5l is a very big starter, you shouldn't need more than 1 ltr to build up two stubbies worth of CPA yeast into something good.

Cheers SJ

 

[Wolfy]

Just a quick question, I made a 2.5L yeast starter from two CPA stubbies with 250g of BE2.
...
I was going to add it to my brew some time late Monday afternoon, but if you think I should wait, any advice would be welcome

If you just tipped the yeast from the stubbies into the full 2.5l starter, its quite possible that it will not be ready to go by today, you'd really want to make sure you have a noticeable amount of yeast before you pitch it.
What is generally a better practice, is to start with a much smaller starter and step it up in size until you reach your pitching volume, where the step sizes should be about 4-6 and no more than 10 times the previous volume.

I just cultured some Coopers yeast from a single longneck, using 1:10 LDME:Water:
Step 1: 40ml yeast slurry from bottle + 40ml in test tube
Step 2: 250ml
Step 3: 1l
Step 4: 2.5l (which I plan to split over 2 brews)
Each step took about 12-24h, and showed good signs of yeast growth and activity before the next step.
The 2.5l has nice layer of yeast at the bottom now that it's been cold-crashed in the fridge for a day or so.

The problem with using such a small amount of yeast in the full 2.5l (if that's what you did) is that it will probably take a long time before the yeast can reproduce enough to notice any activity and during that lag-time it opens up your starter to all sorts of infections. By starting small and stepping up, the ratio of yeast to culture is much higher, so there is better chance at growth and less chance of infection.

 

[Hasa]

Thanks for all the advice, lots to remember for next time

 

[Bribie G]

I made a 750ml starter in a sterilised 1L Schott bottle from two tallies of Sparkling. It took about 36 hours to get some krausen and it was well on the way by three days. Even so it took a longer time than I expected to ferment out. Next time I'll do the wort stepping thing and maybe breed it up for four days, shouldn't come to any harm as long as everything starts out and stays sanitised.


For the forseeable, Coopers Sparkling Tallies are on special at Liquorland 3 for $15 and I buy them regularly because, being true crowns sealers I'm getting up a fair collection now.