Author Topic: Fermentation Timing Question  (Read 377 times)

Offline Rob218403

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Fermentation Timing Question
« on: April 25, 2022, 06:27:58 pm »
I’m very new to home brewing, have done two brews that were kits with pretty thorough instructions that have been really helpful.

That being said as I keep trying other recipes and eventually want to branch out and try creating my own batches how will I know when fermentation is done?

The two previous brews had a Hefeweizen that was ready for bottling after 2 weeks and the other is a raspberry wheat that recommends 2 weeks fermentation and then 1 week secondary fermentation before bottling.


I don’t have any special fermentation equipment to control temperature so most of my brews would be done in my basement which is prob around 68. Does it come down to how much or what you put in your wort? Or the yeast you pitch?

I don’t want to waste time if it is ready quicker but also don’t want to bottle before I should. Is it more about checking the gravity after a certain point? Thank you!

Offline Kevin

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Re: Fermentation Timing Question
« Reply #1 on: April 25, 2022, 06:42:34 pm »
Buy a hydrometer. Your recipe should give you an estimated FG or Final Gravity. For a basic ale you can assume fermentation is complete within 7 to 10 days. Brew your beer... transfer to your fermenter and pitch the yeast then wait close to 10 days before even thinking about looking at the gravity. Take a reading and see how close you are to the estimated FG. It should be pretty close. Wait two days and take another reading and if it is the same then your beer is ready for the next step... usually packaging (bottling or kegging). BTW, if you take a hydrometer reading before fermentation begins that is your OG or SG Original Gravity or Specific Gravity. Using the OG and the FG and an online ABV calculator you can determine the ABV or Alcohol By Volume of your beer.

This is basic beginner steps and I'm sure others will chime in and suggest a refractometer or a host of other tools and they all work and are just fine to have and use. But the simplest way is using a basic hydrometer.
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Offline KellerBrauer

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Re: Fermentation Timing Question
« Reply #2 on: April 26, 2022, 07:50:27 am »
Buy a hydrometer. Your recipe should give you an estimated FG or Final Gravity. For a basic ale you can assume fermentation is complete within 7 to 10 days. Brew your beer... transfer to your fermenter and pitch the yeast then wait close to 10 days before even thinking about looking at the gravity. Take a reading and see how close you are to the estimated FG. It should be pretty close. Wait two days and take another reading and if it is the same then your beer is ready for the next step... usually packaging (bottling or kegging). BTW, if you take a hydrometer reading before fermentation begins that is your OG or SG Original Gravity or Specific Gravity. Using the OG and the FG and an online ABV calculator you can determine the ABV or Alcohol By Volume of your beer.

This is basic beginner steps and I'm sure others will chime in and suggest a refractometer or a host of other tools and they all work and are just fine to have and use. But the simplest way is using a basic hydrometer.

+1

I could not agree more.  A hydrometer is the best and most accurate method for measuring gravity.  I use a refractometer for my initial testing from the boil kettle.  But when accuracy is needed, I rely on the hydrometer.

Another point if you choose to buy a hydrometer: a hydrometer is calibrated — typically— at 60°.  This means that the measurement will need to be adjusted based on the actual temperature of the wort you’re measuring.  I use the conversion calculator in BeerSmith to convert the measurement.  But I imagine there are conversion calculators on the web.

Good luck!
Joliet, IL

All good things come to those who show patients and perseverance while maintaining a positive and progressive attitude. 😉

Offline Rob218403

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Re: Fermentation Timing Question
« Reply #3 on: April 26, 2022, 08:41:28 am »
Thank you for the replies! I have a hydrometer that came with our kit and feel pretty comfortable with how to read the OG and FG.

I guess my question is if I want to try to experiment with coming up with our own recipes and not “know” what the FG should be how do I know when fermentation is mostly done? Does it have to do w the style of beer I brew and that style is usually a FG of a certain range?

Offline neuse

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Re: Fermentation Timing Question
« Reply #4 on: April 26, 2022, 09:09:15 am »
Thank you for the replies! I have a hydrometer that came with our kit and feel pretty comfortable with how to read the OG and FG.

I guess my question is if I want to try to experiment with coming up with our own recipes and not “know” what the FG should be how do I know when fermentation is mostly done? Does it have to do w the style of beer I brew and that style is usually a FG of a certain range?
Unfortunately, attenuation is affected by several factors including mash temperature, malts used, and yeast strain. For starters, you can check the attenuation listed by the manufacturer.

Some other thoughts:
- The need for secondary fermenters is debated. I feel that they are not helpful for most beers.
- During active fermentation the beer temperature will be higher than ambient because fermentation is exothermic.
- A swamp cooler is a simple, low tech method of controlling fermentation temperature. A tub partly filled with water - put the fermenter in it. Add bottles filled with ice as needed. A fermometer (stick-on LCD thermometer) on the side of the fermenter just below the liquid line should read very close to actual fermentation temperature.
- Bottling before fermentation is complete can allow continued fermentation in the bottles - possible bottle bombs. Be sure about the gravity being stable.
- A low range bottling hydrometer is good for checking FG. Mine has hash marks every 0.0005 units, and it can be read closer than that. And be sure to correct for temperature as noted above.

Good luck.

Offline pete b

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Re: Fermentation Timing Question
« Reply #5 on: April 26, 2022, 10:11:15 am »
Thank you for the replies! I have a hydrometer that came with our kit and feel pretty comfortable with how to read the OG and FG.

I guess my question is if I want to try to experiment with coming up with our own recipes and not “know” what the FG should be how do I know when fermentation is mostly done? Does it have to do w the style of beer I brew and that style is usually a FG of a certain range?
First of all, don't get too caught up in the expected FG. It's always a guess and a kit won't have your system and methods in mind. It has to do with yeast, grain bill, and more.
Generally, unless its a very high gravity beer FG will be well south of 1.020. Take a gravity reading with a hydrometer after the krausen (foam on top) goes away, usually 7-10 days after yeast is pitched. Take another gravity reading 2 days later and if they are the same you are good to go. With time most brewers actually learn what finished beer looks, and tastes like.
Its always good to make sure your hydrometer measures 1.000 in distilled water at the temp your hydrometer is calibrated to.
Don't let the bastards cheer you up.

Offline Kevin

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Re: Fermentation Timing Question
« Reply #6 on: April 26, 2022, 10:42:06 am »
Thank you for the replies! I have a hydrometer that came with our kit and feel pretty comfortable with how to read the OG and FG.

I guess my question is if I want to try to experiment with coming up with our own recipes and not “know” what the FG should be how do I know when fermentation is mostly done? Does it have to do w the style of beer I brew and that style is usually a FG of a certain range?

Again, for your average ale of medium to low gravity... let's say 1.070 and under... a ballpark figure is 7 to 10 days. Higher gravity beers can take more time. When I make a barley wine or imperial stout I might let those go for 3 to 4 weeks. But then you have other considerations when making high OG beers which do not directly pertain to this particular question so I won't clutter this answer with those factors.

To take some of the guesswork out of it however have you considered using software? There is not shortage of programs out there and most of them are very affordable.
“He was a wise man who invented beer.”
- Plato

Offline Rob218403

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Re: Fermentation Timing Question
« Reply #7 on: April 26, 2022, 06:14:05 pm »
Thanks for the replies all, I will keep this all in mind in future batches.