Hello Winemakers!
We are going to be using the new forum for discussion of blog posts on www.mastervintner.com and www.northernbrewer.com. These blog posts will direct traffic to these topics so that readers can make a comment, ask a question, or start a discussion with the community. If you are interested in the topic, link over and read the whole post. Cheers!
Using Your Hydrometer, by Tim Vandergrift.
A hydrometer consists of a hollow cylindrical glass tube weighted at the bottom with steel shot, and attached to a long narrow stem containing a tube of white paper marked with a graduated scale. The hydrometer will sink into a liquid until the weight of the displaced liquid equals the weight of the hydrometer. This means that it will sink deeper into a liquid of low density than it will sink into a liquid of high density. This density is described as the liquids’ Specific Gravity. Pure water at 15°C (60°F) has a S.G.of 1.000. Sugar solutions are denser (meaning they have a greater S.G.) and alcohol solutions are less dense (meaning they have a lower S.G.).
Knowing how to use your hydrometer will let you calculate several things about your beer and wine: the potential alcohol, how quickly the fermentation is proceeding, and when fermentation is finished. You read a hydrometer like this: put a sample of wine to be tested in a hydrometer jar. Try not to let the sample foam up as you pour it in the jar—this makes it impossible to read the hydrometer scale. Insert the hydrometer into the jar and twirl it gently with your fingers to shake off any bubbles that might be clinging to it. When the hydrometer has come to rest, read the S.G. from the bottom of the meniscus. The meniscus is the surface of the liquid that climbs up the stem of the hydrometer because of surface tension…
Read the full article here: http://mastervintner.com/blog/using-your-hydrometer/
