1. Swipe vertically to enter your initial re­frac­tome­ter reading, i.e. the mea­sure­ment result for the original wort, just before adding the yeast.

2. Swipe vertically to enter your current re­frac­tome­ter reading, i.e. a mea­sure­ment result after the fer­men­ta­tion process has started.

3. Swipe horizontally to switch between the computation modes. Available modes are the Standard formula, the linear and quadratic formula of Petr Novotný, as well as Sean Terrill’s linear and cubic formulas.

   In general, the Standard and Novotný formulas compute the best overall results. The Terrill formulas are optimized for already finished fermentations.

4. You are done!

   In the upper part of the screen you can now see the computed values for your beer. The next section describes the computed values in detail.

1. The resulting Original and Final Gravity expressed as degrees Plato (°P).

2. The resulting Original and Final Gravity expressed as Specific Gravity (SG).

3. The amount of sugars consumed by the yeast so far, displayed as apparent attenuation and the estimated alcohol concentration as percent by volume (ABV).

   The apparent gravity corresponds to the value you would measure with a hy­drom­e­ter.

The computed values can be customized. This is described in the next section.

1. Use this item to select between the available themes. The Screenshots section below shows the variants in full detail.

2. Use this item to select the application icon for Refracto on the Home Screen.

3. Here you can customize how computed values are displayed. Select either the default to display Plato and SG at the same time or choose a single unit like older versions of Refracto.

4. The Wort Correction Factor is used to convert your initial Brix reading of the unfermented wort into the Original Gravity.

   The brewing literature mentions typical values for this factor in the range from 1∕1.02 to 1∕1.06. By default Refracto uses 1∕1.03.

   In doubt, select a factor between 1∕1.03 and 1∕1.04 which are the most commonly used values.