Expert: John Snyder - 2/10/2009

Question
QUESTION: I have a basic hydrometer.  The beer I am able to brew at this time is 2
gallons each brewing.  I use a standard malt extract can, and I am ready to
advance to a Cooper, 3+ lb. can of prepared, no-boill extract.  My question
is this:  For the 2 gallon brew, what would you estimate the beginning S.G.
reading should be on the hydrometer?  What should the end reading be?  I
know there are variables, but could you give me an average or general
estimate of how to figure this for an end result of 4.5% alc., for example.
Is there a chart available anywhere that I could refer to, or a formula that
works?  Thank you so much for your help and reply.   Marty

ANSWER: First thing you need to know,is that the beginning and ending S.G.has already been determined by the process involved in making Home Brewing Ext.

Here is a range of starting S.G's of various brews.

Lite beer--1020-1040
most beers--Lagers-Stout-Porter-Pale Ale---1040-1050
India Pale Ale-ESB---1050-1060
Bock-strong ales---1060-1075

End S.G.ranges---1.005 to 1.012

use this formula for alcohol determination,it's pretty accurate:

Degree Plato=S.G.minus(-)1divided by 0.004

Beginning S.G.=1.052
     1.052 minus 1.0=.052
      .052 divided by .004=13.0

Ending S.G.=1.010
      1.010 minus 1=.010
      .010 divided by.004=2.5

13.0 minus 2.5=10.5

10.5x.42=4.41% alcohol by weight

4.41x 1.25% =5.51% alcohol by volume

.42 is alcohol per 1/10th Plato fermented
1.25% is to change alcohol by weight to volume

         Hope this is of help
any other questions please ask
         John

---------- FOLLOW-UP ----------

QUESTION:      I had a 1.21 lb. can of extract that I found after more than 5 years of
storage.  The yeast packet was not good anymore, but the can looked good.  
It was called, "West Coast Pale Ale".  I purchased a packet of Cooper's yeast
and used the can according to instructions. The brew looks dark, but the
fermentation was very strong.  I bottled it with the appropriate amount of
priming sugar and it is now 6 days since the bottling.  When I had used the
first can I had of West Coast Pale Ale, the results were very good, but the
brew was light gold in color.  What is the darkening indicative of?  Do you
think the brew is spoiled because of the age of the extract can?  Thank you
very much for your reply.  It will be much appreciated and helpful to me .

Answer
During the production of malt extract,the concentration of the wort produces meanoidins,a color pigment that darkens the extract.Liquid malt extract also contains water,that allows the coloring reaction to continue at a slow rate as the malt extract ages..As a result liquid malt extracts will continue to get darker as they age.The brew itself,will have it's final flavor affected,for the worst.In addition the finished gravity will be an issue.Oxidation is the trigger,for the darkening.Liquid malt extract,should not be used,if over one year,from date of production.Dry malt extract is not subject to this.

         John