Yeast Help

[dougsbrew]

say for instance you use pitching calculator and it says you need 18grams of dried yeast for your brew and your packet is 11.5grams, can you increase the cell count somehow?? i know alot of people will say just add another packet but thats another $8 that could be saved if you could grow a starter.
i'm guessing a starter of half a litre of water, 10grams dextrose, packet yeast, let sit for 24 hours would increase cell count??
any info on this would be greatly apprieciated.

 

[np1962]

1. Don't use dextrose, use malt extract.
2. 10gm in 500ml will give a 1.010 wort, you need something around 1.040 to get any growth/worthwhile ferment.
3. A full pack of dried yeast will ferment out a small starter with minimal growth as their are enough numbers to do the job. Pitching into 2000ml would give you some growth.
4. One pack would normally be sufficient for a standard 23L batch up to 1.050 wort unles it is a fairly old pack.
Hope this helps a little.
Nige

 

[dougsbrew]

thanx for reply, i normally ferment 20L at around 1.046 so i guess 11.5g yeast will be fine.
i supose those pitching calculators are overestimating to acheive that little extra advantage.

 

[A3k]

I'd say you'll be right with one unless you're doing a lager.

Dried yeast is meant to have nutrient in it that gets it cranking from the get go. If you make a starter you use this up too early.

 

[ekul]

Also read about reusing yor yeast. At $5 minimum a batch minimum this is a decent saving. All i do is bottle the yeast cake into some stubbies and use as required.

 

[dougsbrew]

I'd say you'll be right with one unless you're doing a lager.

Dried yeast is meant to have nutrient in it that gets it cranking from the get go. If you make a starter you use this up too early.

yes it is a dried lager yeast i use S-189. will be trying W34-70 next.
so will 11.5g be insufficent, would it be advisable to grow a starter.
i recently did a coopers euro lager which comes with a 7g yeast, fermented well in around 8 days.
i'm guessing coopers strain multiplies quickly.

 

[Bribie G]

Kits come with ridiculously small yeast packs and they should be taken to court over it B) - the packs supplied by the likes of Craftbrewer (no affiliation) contain an excellent quantity for two brews pitched at around 20 degrees. Dried yeast has been optimized with good cell walls and nutrient uptake so that it's ready to go when re-hydrated in warm water per instructions and up to 100% of cells will survive. From there on it's up to you to provide a nutrient rich wort with good oxygen levels.
Dried yeast does not benefit from being "started" - that's more a job for subsequent batches when you are using yeast cake saved from the last batch.

edit: although underpitching can be bad, overpitching can also be bad, with the risk of runaway fermentations, too short a fermentation and the end product having a different flavour profile. I'd stick with the 12g pack for most "normal" beer styles.

 

[dougsbrew]

thanks for the info, one pack sounds good to me.
if it was 2 packs i guess you may as well use wyeast packs as it would work out cheaper.

 

[pcmfisher]

Dried yeast has been optimized with good cell walls and nutrient uptake so that it's ready to go when re-hydrated in warm water per instructions and up to 100% of cells will survive. From there on it's up to you to provide a nutrient rich wort with good oxygen levels.

If its in good health and ready to go, and a dry yeast is supposed to have enough cells so it doesn't have to multiply, do you still need good oxygen levels??

 

[Bribie G]

If its in good health and ready to go, and a dry yeast is supposed to have enough cells so it doesn't have to multiply, do you still need good oxygen levels??

Yes it does need to multiply but when you pitch a dried yeast it's optimised to hit the ground running.

 

[pcmfisher]

I didn't say that very well, I will try again.

Optimised to hit the ground running - doesn't that mean bud a couple of times using available goodies it comes with in the sachet and without the need for oxygen then get right into chomping sugars. That is assuming your pitch rate is good