Shaking fermenter when airlock activety slows

[TimelessCynic]

Is it bad form to shake the fermenter when the activity on the airlock slows?

The yeast become a little more active when agitated and i figure it would get my FG down a point or two.

Any thoughts?

Thanks.

 

[billl]

It's generally unnecessary, but it won't hurt anything.

 

[m3n00b]

Shaking or swirling?

 

[NewWestBrewer]

Is it bad form to shake the fermenter when the activity on the airlock slows?

The yeast become a little more active when agitated and i figure it would get my FG down a point or two.

Any thoughts?

Thanks.

From my understandinng, shaking is bad but swirling is ok. You do not want to aerate it after the yeast is in.

 

[BrewChem]

Swirling to roust the yeast won't hurt anything... shake it too hard and it can be like shaking a bottle of soda... messy..!

 

[flars]

Is it bad form to shake the fermenter when the activity on the airlock slows?

The yeast become a little more active when agitated and i figure it would get my FG down a point or two.

Any thoughts?

Thanks.

Pitching the proper amount of yeast and controlling your fermentation temperature will get the FG where it is supposed to be for the ingredients used. Swirling up dormant yeast, where the amount of yeast and fermentation temperatures were optimum, won't put them back to work.
There may be some added airlock activity evident though. This will most likely be from forcing CO2 out of solution.
May sound like heresy because stuck fermentations can sometimes be restarted. In the case of stuck fermentations other fermentation process factors also need to be changed.

 

[TimelessCynic]

Thanks for the input everyone.

I guess i will leave my brews as they are unless I have one that has a very high FG. Then I will swirl and see if my FG lowers.

Can someone explain attenuation percentages to me please. For example if i have two batches of 1.050 with different yeasts that have different attenuations. One ends at 1.005 and one ends at 1.010 i would assume the 1.005 has higher attenuation. If the attenuation percent and OG are know. How do i determine the FG?

THANKS

 

[billl]

"If the attenuation percent and OG are know. How do i determine the FG?"

The attenuation is never known. It really depends on how you mash, if you use simple sugar, the temps you ferment at, your O2 levels, the yeast in question, and the pitch rate. The attenuation% is always a range of values from the manufacturer - and often you might not even fall in that range. eg I mash an IPA at 148 for 90 minutes and always get higher attenuation that than wyeast claims.

 

[TimelessCynic]

"If the attenuation percent and OG are know. How do i determine the FG?" The attenuation is never known. It really depends on how you mash, if you use simple sugar, the temps you ferment at, your O2 levels, the yeast in question, and the pitch rate. The attenuation% is always a range of values from the manufacturer - and often you might not even fall in that range. eg I mash an IPA at 148 for 90 minutes and always get higher attenuation that than wyeast claims.

If i start at 1.050 and end at 1.005 am
I at 90% attenuation. Same as 1.10 and 1.010????

 

[billl]

"If i start at 1.050 and end at 1.005 am
I at 90% attenuation. Same as 1.10 and 1.010????"

Yes. You just aren't going to be able to predict it exactly in advance. eg you start at 1.050 and the yeast averages 90%, you could easily finish at 1.010 if you mashed really high and used a bunch of specialty grains.

 

[FarmerTed]

I do it every time; it's not going to aerate the beer as long as the airlock is sealed. I want to make sure I get good attenuation, and I want to release as much CO2 as I can as well to help out the yeast.

 

[TimelessCynic]

I got it down a point by swirling. From 1.009 to 1.008. Sample tasted great.