Hot answers tagged yeast-starters
18
The recommended cell count for ales is 0.75 to 1 million cells per milliliter per degree plato (ca. 4 gravity points.)
For 5 gallons of typical strength beer of 1.048, that's about 12 plato, so you'll need
1 million x 18900 x 12 = 226.8 billion cells.
According to wyeast, the smackpack contains at least 100 billion cells, which is half of what is needed. ...
9
Speaking from experience as a molecular biologist. Erlynmeyer flasks are nice for a couple of reasons. The main alternative being a standard beaker which is essentially the same size at the top and the bottom. First off the neck size makes it easy to hold in the hand. Second a smaller opening reduces the chance of getting airborne material into the flask. ...
4
You don't necessarily need to make a starter if you are re-pitching within a few weeks because the viability of the yeast will still be pretty high. But, if you store the yeast for much time you should always make a starter. This ensures that the yeast is still viable and it will help ensure the yeast are active so you don't have a long lag time during ...
4
There are three main reasons for stepping up:
having too much medium and too little yeast increases the risk of contamination considerably.
a large quantity of medium causes the first few generations of yeast to bud rapidly, resulting in lots of scar tissue which functions poorly as a membrane.
It allows the strength of the wort to start out low and ...
4
A krausen is created mostly from coagulating proteins and high yeast activity. You may still get a krausen at ale temps with the lager yeast due to the level of activity, but in general it's hit and miss how much yeast you get from top cropping, even more so with a bottom fermenting strain.
In your shoes, I would divide the smack pack yeast between two ...
4
A short starter is fine. I often have starters that begin stirring when I start the brewday, so they're only going for 8-10 hours max. With appropriate handling, the risk of contamination can be mitigated and reduced to be negligible.
Due to the small amount of wort, lag time with a vial of yeast is at most a couple of hours (assuming a fresh vial.) Yeast ...
4
The cake is referring the yeast the was produced from a previous batch of beer. Yeast reproduces as it ferments the beer. The layer on the bottom of the fermenter is the yeast that grew during fermentation. Some people will brew a batch of beer and pitch it directly onto the cake created from a previous brew. The preferred method would be to wash the yeast ...
3
You should be fine doing this. Don't aerate until the next day. For an added clarity benefit, if you are chilling all the way to pitching temp on brewday (or at least belo 130-140), you can 'decant' the wort the next day into a different sanitized fermenter and leave the trub behind. This can also help to aerate. FURTHER, this will also basically allow ...
3
For starter wort you can use the 1/2 tsp and a sachet of yeast hulls, although I usually double this, just to make sure the yeast have all they need. I've even used 1/2 tsp in a single 1 quart starter with no ill effects.
The yeast hulls are necessary since they contain trace elements that are essential for the yeast. The diammonium phosphate is only ...
3
With a starter that large, it's best to pour off the starter wort.
To do this, you can either leave it for a few days for the yeast to settle out, or put the starter in the fridge a few hours before it's needed. Either way, once the yeast have settled, you can pour off the starter wort.
You can then put the yeast somewhere that's close to pitching ...
3
I prefer to give my starters four or five days. Fermentation is usually done in 24 or 48 hours, but I like to cold-crash the starter so that the yeast falls to the bottom. That way, I can decant the beer off the yeast, and pitch just the yeast. If you only give your starter 24 hours, you're forced to pitch the whole starter into your wort. Not a big deal, I ...
2
While starters ideally don't make use of an airlock to promote maximum O2 exchange, some people prefer to use an airlock to counter wild yeasts and other contaminants. The narrow neck on the conical flask makes using a stopper and an airlock much more practical.
Alternatives to rubber stoppers are foam stoppers which permit gas exchange. Again, these would ...
2
I think it's just a matter of preference. If you rack to a carboy and store it cool, then the few microbes in the airspace will not cause too much trouble before morning.
However, I personally feel that once the wort is ready to pitch it's preferable to pitch the starter then - even if it's only been stirring for 8 hours - since it ensures you have the ...
2
First, make sure there's yeat there to capture! Some people mistake any sediment for yeast. For instance, every German lager I know of is filtered so there won't be any yeast. Assuming there is yeast, make up about 2 cups of 1.020 wort. Flame the opening of the bottle with the yeast you want to capture and pour the sediment into your starter wort. Let ...
2
A dry sachet contains about 200 billion cells when new, with a decrease of around 4% per month thereafer.
For a beer in the 1.070 range, recommended pitching rates are 1-1.5 million cells / ml / 4 SG or about 330-450 billion cells in 5 gallons. So pitching a single pack of 200 billion cells is going to be underpitching, and one pack split is very much ...
1
The bigger question is WHY fermentation stopped in the first place? Did you pitch enough viable yeast? If not i would pitch some more yeast. Are you fermenting to cold? If so give the fermenter a good stir with a sanitized spoon and put it in a warmer spot.
How are you sure fermentation is stopped? Have you taken a gravity reading? Sometimes vigorous ...
1
Definitely be patient. fermentation at lower temps (even 50deg F) is slower than the higher temps, so it will likely take longer to attenuate...maybe even longer than the suggested 4 weeks. I would definitely make a bigger starter for future batches. You may need to pitch another starter to get full attenuation though.
1
Servomyces is simply dead yeast. Prior to being killed, it was fed micronutrients which have been stored in the yeast. There's no harm pitching more into your starter, assuming you then later pitch to 5 gallons or more. If your starter yeast don't use all the nutrients, your main brew certainly will, so there's no harm pitching the entire capsule.
The White ...
1
You still get Krausen, but I wouldn't harvest from the top.
I'd suggest scooping some up in a sanitized mason jar and making a starter from there after racking the steam beer to secondary. You could search google washing yeast if needed, but you should be fine from the starter. You won't get a lot of steam like flavors from that, but a huge amount of cells ...
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