Specific gravity advice

[panzerd18]

Hello all,

My start specific gravity was 1.050. After three days I retrieved a reading of 1.024. On the forth day 1.018.

I understand you must wait until after two consecutive days the specific gravity stays the same to bottle. How much further to you think it will go? The foam has started to die down now on the surface of the liquid.

 

[rosshorne]

Depends on just about everything. White labs did a PowerPoint for trying to guess.

When I'm unsure I just leave it in the fermentor for two weeks.

 

[mr_wibble]

Can you just forget about it, and start planning your next brew ?

It's a bit difficult to guess what the FG will get to, it depends on a lot of factors.
But if it's dropping multiple points per day, just leave it to do its thing. Everything will be OK.

Here's how I ferment:

[1] Put wort and yeast into fermenter.
[2] Come back 2 weeks later, check gravity.

Sometimes if I'm really excited about a brew, and c'mon - who isn't?! - I'll peer through the side of the fermenter.

 

[calobes]

Hello all,

My start specific gravity was 1.050. After three days I retrieved a reading of 1.024. On the forth day 1.018.

I understand you must wait until after two consecutive days the specific gravity stays the same to bottle. How much further to you think it will go? The foam has started to die down now on the surface of the liquid.

You could plug your recipe into beermate or similar software and it will give you approx og and fg.
It's a free and quick download

 

[panzerd18]

Cool thanks for that

 

[beermeupscotty]

'How to Brew' by John J. Palmer is an excellent resource for new (and old) brewers, and would help you with this kind of question (and many others).

It's also mostly available online; the relevant page from the book is: http://www.howtobrew.com/section1/chapter6-1.html

So, while the FG will depend on a lot of factors, you can make an estimate based on the attenuation rating of the yeast.

I've plugged the equation from above link into a spreadsheet of mine for calcs on FG / attenuation / alcohol etc. The equation (as I use it) is:

FG = OG - [(OG - 1) x %att.] - You should be able to find the attenuation % of the yeast from the supplier. e.g. https://www.wyeastlab.com/rw_yeaststrain_detail.cfm?ID=5

Or you can just use an online calculator like this (second form): http://www.angelfire.com/wi3/johnsons/abv.html