A question for the home brewers out there

[Hammock Hamster]

Rather than hijack the other home brewing thread I thought I would ask the collective brewers a newbie question.

So far I have made a few 1 gallon batches of mead from first principles that have turned out ok, I have only ever followed a recipe I got hold of making a few tweaks here and there, the only equipment used was a glass demijohn, bung, airlock plus ingredients and sterilising solution.

After reading another brewing thread I got googling and realised that as nice (and reasonably alcoholic) as my attempts are I have no idea what he alcohol content is.
As far as I can understand it I can get a hydrometer to find this out but am struggling to get my head around it.

Can anyone give me an idiots guide to this, also do measurements have to be taken throughout the fermentation process or can I get the alcohol content in one hit at the end so to speak?

All the best, Hamster

 

[spandit]

You have to measure before and after, sorry...

 

[leedsbrew]

Hi HH

A hydrometer works by measuring the specific gravity of a solution (in this case fermentable sugars in water).

The general idea is you take the specific gravity of the solution (un fermented mead or must) then take the SG after fermentation has finished!

As the yeast metabolises the fermentable sugars into alcohol and co2 the SG of the solution will go down.

You then take the first reading and subtract it from the second (lower) reading and multiply that value by 105 to get the alcohol % by Volume.

Failing that use the calculator here

http://www.brewersfriend.com/abv-calculator/

When it comes to hydrometers most are calibrated to 20oC although it will tell you on the stem. (SG readings with hydrometers are affected by temperature).

You should take the reading where the liquid transects the stem of the hydrometer not at the top of the meniscus

So in this pic the reading would be 1.062 rather than 1.060

Hope that helps

Cheers

LB