Starting Gravity and Ending Gravity

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Fantastical

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I'm just wondering about the relationship that starting and ending gravity have with each other.

I keep having batches that have a high ending gravity. One was 1.013 and this last one was 1.022.

Are these stuck fermentations? Both had a starting gravity of 1.042.

Do ending gravities need to be below a certain level?

Does the ending gravity correlate to the starting gravity?

Is there a desirable ending gravity and does the attenuation relate to anything other than alcohol %?

Sorry for the barrage of questions!


Thanks!
 
Are these stuck fermentations? Both had a starting gravity of 1.042.

Not necessarily. % of fermentable sugars vs unfermenatbles vary. Not all sugars are able to be fermented by the yeast.

Do ending gravities need to be below a certain level?

Per style yes, kind of. A higher FG will tend to mean a sweeter beer. Lower FG, drier.


Does the ending gravity correlate to the starting gravity?

Yes, the difference will tell you how much alcohol you have in your beer. It really tells you how much sugar you have in your beer and the math takes over from there.

Is there a desirable ending gravity and does the attenuation relate to anything other than alcohol %?

To each his own and again, different styles have different target ranges.

I for one, never check the FG. At that point, I don't care.
 
I check the FG to make sure I got a reasonable attenuation. However, the FG also depends on a lot of factors. If you are extract brewing, it is really hard to get the FG below 1020 (at least it was for me) and for AG brewing it depends on your mash temps. Yeast health (and happiness) is also very important for attenuation.
 
Thanks for the responses! Sorry I should have specified that my batches are all grain. I like my beers less sweet. Any tips to get that gravity down more or reduce the amount of unfermentable sugar in my brew? Thanks!
 
Thanks for the responses! Sorry I should have specified that my batches are all grain. I like my beers less sweet. Any tips to get that gravity down more or reduce the amount of unfermentable sugar in my brew? Thanks!

Mash low, pitch more yeast. :mug:
 
Depends of the type of beer you are brewing and the OG. Simple sugars like table sugar and honey are completely fermentable and if they are used to replace some of the malts then the FG will be lower and the beer will be drier. You could also mash lower. If I want to get some pretty good attenuation I will usually mash at 151-152. You can also help the yeast out too. When you see fermentation slow down, usually after 2-3 days depending, increase the temp about 4-5 degrees. This will ensure that they dont flocc out too early and keep fermenting. You wont have to worry about off flavors created by increasing the temp b/c by the time the beer as slowed down all of the flavors the yeast will give off have been made.
 
Oh wow thanks coypoo! I didn't even see your first post. I will try moving to a warmer temp once fermentation slows down!
 
Will that also reduce my starting gravity or just the sweetness of my beer?

No. Mashing low tends to increase the attenuation (basically fermentability) of the beer. Pitching more yeast also helps to ensure that every bit of fermentable sugar is consumed by the yeast thereby reducing any residual sweetness and "drying" your beer out. OG is strictly based on the grain you use and the job your system does at extracting sugars from them. It also has some to do with the boil (i.e. how much is evaporated).
 
Oh and one more thing... By mashing low what temps do you mean? 150f?

A typical "low" mash for a beer you really want to dry out is about 148-150. I mash at those temps sometimes when I do IIPAs. Most typical beers I ferment at about 152. 154 or so is considered medium body. 156 and a bit higher is full body.
 
I'm adjusting my brew as we speak. :)

What about mash time length? Assuming temperature remains constant, does it have any effect on fermentable sugars and OG?
 
I'm adjusting my brew as we speak. :)

What about mash time length? Assuming temperature remains constant, does it have any effect on fermentable sugars and OG?

You'll get a lot of responses to this, but for me, I only mash for 45 minutes for most beers. Maybe 60-90 on a really high alcohol beer. The reason I only do 45 min's is b/c all of my conversion has taken place by this time, and anything longer is a waste of my time. On Kai's website, http://www.braukaiser.com/wiki/inde...ng_Efficiency#Measuring_conversion_efficiency, there is the chart on the right. Take a sample of your first runnings, if they line up with the SG, then you converted 100% of your malt. For me, this takes 45 minutes for most ~6.5-7% alcohol beers.

When you start talking about mash and OG it will be a whole diff discussion on efficiency, but that is another thread :mug:
 
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