Density

Density is measured in sake via hydrometers to determine fermentation progress and sweetness/dryness. Baume and SMV are the density scales typically used in sake brewing. Baume/SMV has an equivalent to Specific Gravity, Plato, and Brix but other scales can be more difficult to read with precision.

There are two types of Baume scales, a heavy scale for liquids denser than water and a light scale for liquids less dense then water. The Baume Light scale is not typically referenced in sake brewing, instead a specialized hydrometer called the Sake Meter Value (SMV) is used to read density when sake transitions from more to less dense than water.

Text book of Sake Brewing P118: Table 5-4 Relationship between Specific Gravity, Sake Meter Value, and Baume Degree

The range of Baume heavy hydrometers is between 20 and 0. An SMV hydrometer is equivalent to Baume between 3 to 0 but also goes lower. These numbers are equivalent to -30 and 0 respectively and then lower down to +20. For example if you have a baume heavy reading of 1.2 you will have an equivalent SMV reading of -12.

Needs:

• ~50ml sample of clear sake
• Graduated Cylinder
• Baume Hydrometer
• SMV Hydrometer

Method:

1. Place sample in graduated cylinder
2. Place appropriate hydrometer into sample
3. Read and record your result