8
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Will reused yeast change beer taste?
we can get away with re-using yeast, because Mutation isn't instantaneous, it take multiple generations to change a whole batches properties. Also bigger brewers use a "mother culture" to grow more ...
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6
votes
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What does a gravity reading really mean?
Specific gravity measures density, which is mass/volume. If you measured the total mass of your system (3000g + 300g) you would have gotten 3300 grams, but the volume is not 3000 ml because you added ...
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6
votes
Production of yeast
Almost certainly the starter yeast is yeast slurry that's been stored frozen in liquid nitrogen. Interestingly, one of the most common methods is to store it inside sealed-off portions of plastic ...
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5
votes
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Why does Northern Brewer's Fast Pitch Canned Wort not require any boiling?
Malt extract does not need to be boiled to make beer. It is perfectly possible to make beer using extract and cold water although it s a little easier if you dissolve the extract in boiling water ...
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4
votes
Alternative to stir plate for yeast starter (and erlenmeyer flask)
I use a 750 ml bottle, sanitised aluminium foil and a rubber band. Keep aerated by stirring it gently, occasionally during the first 12h; I stir every 6th hour or so. After 18-48h I use it or ...
- 711
3
votes
Cell growth factors in different types of yeast starter
If you're comfortable doing the math yourself you could use some bioreactor equations to model the yeast growth.
I would start with the assumption that growth is limited by initial population, ...
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3
votes
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Simulating a yeast starter for fine tuning a stir plate
I haven't noticed any difference in the performance of my home-built stir plate between water and wort/yeast with one exception. I often make two-stage starters and refrigerate the flask between ...
3
votes
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Risks of pitching a high gravity starter?
Just cold crash the starter, decant the beer off and pitch the yeast slurry.
The main function of a starter is to grow yeast to a proper cell count for your batch. It's actually pretty hard to over ...
- 18.5k
3
votes
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Really fast attenuation with starter. Is this to be expected
Yes it's totally possible. But I would expect a lower OG than you estimate. 1.071 is possible to drop out that quick but not very likely.
Take a hydrometer AND refractometer reading on the finished ...
- 18.5k
3
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Why is a yeast starter necessary? How is it different than standard fermentation?
The point of a starter is to obtain a higher and healthier yeast count before you pitch into the wort. This is accomplished because the 100g of DME/Liter create enough sugar for the yeast to reproduce ...
- 560
2
votes
Risks of pitching a high gravity starter?
Assuming a 5 gallon batch, this over-sized starter will contribute roughly 10% of the volume of your beer. So any changes it makes to the flavor will likely be small and difficult to detect in even ...
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2
votes
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Used Wrong Yeast.... Final Gravity Too High
I strongly advise against yeast nutrients, unless you are sure that this addition will not be sensed in finished beer even if yeast will fall to eat it. Once I had a batch less than optimal due to ...
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2
votes
Used Wrong Yeast.... Final Gravity Too High
One can pitch dry powdered yeast directly into a brew. It often works well but sometimes not. In my entire brewing career(?!?) I have never used a yeast nutrient(!?!). Some do, some don't.
I usually ...
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2
votes
How much yeast can I reuse from the last fermentation?
The Mr Malty yeast calculator (need flash installed) has an option to calculate how much yeast cake you should re pitch. Its a ballpark estimate since one yeast cake isn't the same as the next, buts ...
- 276
2
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How much yeast can I reuse from the last fermentation?
No specific proportion. Quite a few people reuse the whole "yeast cake".
There are a few gotchas, though. One of them you kinda mentioned - it's not just yeast in the "cake", but all other stuff you ...
- 1,498
2
votes
What is the control recipe for official yeast attenuation ratings?
I was able to find at least one paper in which a standardized wort was used to classify many (153) yeast strains based on, among four other parameters, degree of attenuation.
The wort used was an
'...
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2
votes
What is the control recipe for official yeast attenuation ratings?
I have veiwed a few papers and this one contained similar proportions to other references but was the only one to contain a reference for the source of the proportions.
Isolation and Characterization ...
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2
votes
Yeast harvesting from bottle and fermenter
Yeast from bottles always has to be stepped up several times. Most of it will be stone dead (having been through the wars in both the fermenter and the bottle and having aged for far too long) so you'...
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2
votes
Accepted
Yeast harvesting from bottle and fermenter
Do a step starter.
Start around 500ml and double for each step until you get your pitch amount needed.
- 18.5k
2
votes
What's the minimum amount of active dry yeast to start a ferment?
Spray dried yeast is what the spherical nodules are composed of. Brewers yeast has lost the ability to form spores.
Yeast population do grow rapidly in the log phase of yeast growth. That is usually ...
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2
votes
Accepted
Can yeast survive being almost frozen?
Yeast can survive freezing. You will have to bring the yeast back to room temperature without over heating them, so naturally let them warm up.
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2
votes
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What is a realistic growth factor in large volume stir plate yeast starters?
'Is such a high growth rate (assuming that everything is optimal) actually possible[...]?'
It sure is. Yeast will pretty much grow indefinitely as long as there are no nutrient limitations or ...
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2
votes
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Alternative to stir plate for yeast starter (and erlenmeyer flask)
You could build a stir plate - you probably already have most the stuff laying around.
Step 1: Gather a computer fan, power supply, stir magnet, and neodymium magnets and 2 L mason jars.
Step 2: ...
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2
votes
Alternative to stir plate for yeast starter (and erlenmeyer flask)
A stir plate does two things. Both can be done manually by swirling your vessel.
Provides the yeast a good amount of oxygen.
Reduces yeast lost, from lifting out with krausen and drying on the sides....
- 18.5k
2
votes
Home brewing for undergraduate study
Yes, there is a possibility to convert those starches into fermentable sugar, but it will depend on the source.
With malt, the process of mashing consists in keeping the grain at a temperature to ...
- 4,806
2
votes
Question about Ginger Bug
You're pretty much spot on. A couple of notes-
Capturing wild yeast is OK but uncertain. I've always preferred to keep wild yeast out of my bug because it's much more likely (at least over time if ...
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2
votes
Can I add yeast and sugar during the first 10 days?
So the reason for removing juice rather than getting a larger container is to protect the sanitary environment of the juice bottle. If you start transferring juice into a new container, you are ...
- 975
2
votes
Alcotec VS Still Spirits
Well, it depends what you're making. Alcotec is distillers yeast- I really wouldn't recommend it for use if you're not running whatever you make through a still. However your title mentions Still ...
- 1,783
2
votes
Accepted
Yeast packaging formats by example
Active and dormant are part of the yeast cycle and has nothing to do with sales or packaging.
Yeast becomes active when it detects that is in a nutritious environment. Then it starts fermenting. When ...
- 3,665
1
vote
Alternative to stir plate for yeast starter (and erlenmeyer flask)
I Use various size canning jars, I have the, from .5L up to Half Gallon.
I only fill them up Half way to 3/4 full. And when making the starter, I leave the lid partially screwed on.
Then during the ...
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