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. ...
6
The point of a stirplate is to help the yeast propagate by aerating the wort. Yeast Propagation and Maintainance claim stirring can increase yeast cell count by 10-15 times, compared to simply using an airlock (non-aerated) or 2.5 times the cell count of the traditionally aerated starter (aquarium pump).
It's important not to use an airlock, since the ...
6
Start early- take the yeast of out the refrigerator ~3 days before brewday, and let it warm up to room temperature.
Boil a pint (2 cups) of water and mix in 1/2 a cup of dry malt extract (DME). Boil that for 10 minutes.
Optionally add yeast nutrients at this point.
Cool the water to 80 degrees or less (set the pan in a sink with an inch or two of water, ...
6
Pitching the slurry is key to your process here. The higher temp will put some less desirable flavors into the starter wort. So crash chilling and pitching the slurry is the best bet.
I think I remember hearing a podcast with Chris White from White Labs say they propagate most yeast (even lager yeasts) at 80F. Most yeast grows best at temps above normal ...
5
Those using airlocks are missing the point of the starter, as you mention: you need O₂ to be introduced to promote healthy yeast reproduction. (You also want to get CO₂ degassed out, as well, which is another benefit to a stirplate, as it will help achieve both goals.)
I wouldn't even worry about sanitizing the aluminum foil coming just off a roll, but if ...
5
The yeast will grow and multiply in dextrose. Supposedly, though, while they grow up in the dextrose they begin to down-regulate the genes required for fermentation of maltose. So when you pitch them into the maltose rich wort, they struggle a bit before fermentation really takes off. How big of an impact it has on the final beer is hard to say.
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4
I recommend making a yeast starter for every beer you use liquid yeast for (I have little experience with dry yeast because I stopped using it after my first few batches). You don't need a starter all the time, but it's on my list of best practices.
You will almost always see better fermentation if you use a starter. It will start faster (which helps a ton ...
4
Here is a link to a NB document that outlines how to use one and two stage yeast starter. There are some lengthy equations that can easily be entered into a spreadsheet for easy calculation. It will also give you the different rates when using a stir plate.
4
Your brew will definite taste salty with that quantity of minerals added. I would use a third of that amount. 150ppm calcium and 250ppm sulphates is really the upper limit of what you can comfortably use in the beer, and you will still taste a little salt up front, but often it goes with the style.
Here are some guidelines from the HBT wiki,
...
4
Assuming you boiled the DME with water, and chilled, then there's no problem. Old DME may not taste especially great, but it still has all the sugars and free amino nitrogen that the yeast need, and is still fit to function as wort for a starter.
Before pitching, decant a little and have a taste of the starter. Not only will this let you sample some of the ...
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
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
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
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
A missing piece of information is how much you're pitching into. If beersmith is saying you need 160 billion, then you're probably pitiching into about 20 litres (5.7 gallons).
Yes you could make a starter tonight and you'd be perfect for pitching on Sunday. Typically a starter needs 24-36 hours for the yeast to reproduce. According to Jamil's yeast ...
3
You'd need to check the Mr Malty pitching calculator to be sure, but I think you are going way overboard with the starter. For a 1.085 Belgian ale that started off in a smack-pack, I'd make about a half gallon starter of 1.040 gravity and call it a day. I've made a similar Belgian in the past, and did a 1qt starter stepped up with another 2 quarts, and it ...
3
You can put that foam stopper in your flask while you boil the starter wort. The steam from the boiling starter wort will sanitize the stopper for you. Or you could put the foam stopper in a covered saucepan with a bit of boiling water so that it's sanitized by the steam.
My understanding of foam stoppers is that, although not airtight, their structure ...
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 ...
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 ...
2
To put a nail in this question: You do not need to puts hops in yeast starters.
The main reason to add hops to a yeast starter is because the alpha acids in hops have an antibiotic quality that inhibits the growth of Gram-positive bacteria, thus making way for brewer's yeast to do its work.
In practice, assuming you properly sanitize (which you ...
2
There is no reason to hop a starter. The quantity compared to the full batch shouldn't have a dramatic effect on the flavor profile and the antiseptic qualities of hops should not be necessary if you prepare the starter well.
The best method I found for preparing starters is to make a 2-3 gallon batch of wort using a light extract and then filling canning ...
2
Whether to just pitch the whole thing, or chilling (to drop the yeast if necessary) and decanting the liquid depends on your beer and batch size.
For example, to make a Russian imperial stout, I might make a large 2 liter starter (maybe even larger). Generally, starters should be minimally hopped and have an OG of about 1.040-1.050. If I were to pitch this ...
2
You're using the proper method.
Some people pour off the flat beer and only pitch the solid yeast, but it's overkill, especially if you're making a starter with Pale LME.
If you're making a starter from wort you saved from your last imperial black-patent malt bomb, and you're pitching into a one gallon batch of wife lager, then definitely pour off the ...
2
I would certainly follow JZ's advice over NB's. While I know and respect the people at NB (hey, they put out kits of my recipes!), I know for a fact that JZ has worked with Chris White to do detailed studies while NB is just repeating commonly held "wisdom". You're also comparing apple to oranges since NB recommends 2 steps and JZ is talking about a single ...
2
Assuming you are using his pitching rate calculator, here is what I would suggest: Switch it from "Simple Starter" to either "Simple Starter with O2 at Start" or "Simple Starter with Intermittent Shaking."
O2 at Start basically means you shake it up really well when you start the fermentation of the starter (or if you add oxygen via diffusion stone).
...
2
One thing that I think makes using starters a lot easier is preparing a bunch of starter wort at one time, keeping quarts in canning jars and then when you are ready to make your starter, all it really takes is a clean vessel, your yeast and a jar of the wort. Making it so much easier will really encourage its use and as you point out, it is a big help to ...
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