# Brew Log

## Batch Performance

Will show a summary of your brew session.

### Efficiency

**There are four main types of efficiency in the brewing world.**

More details about the Brewing Efficiency Chart
Efficiency calculations only apply to All Grain, BIAB, and Partial Mash recipes. Each type references a different point in the brewing process. The system uses **Brew Log entries** to compute each of them:

**Mash Complete:**

**Mash Complete:**

*Measurement:*Gravity - Sample taken from first runnings or directly from mash. Be sure to mix wort prior to taking gravity sample.

Volume - The sum of the strike water and all infusions prior to sparging.

Measures:

**Conversion Efficiency.**The percentage of sugars converted from the total potential sugars in the mashed grains inside the mash tun.The equation the system uses comes from Braukaiser's article on Understanding Efficiency. We believe this is the most accurate equation out there because of the 3rd term which accounts for the volume increase from the extracted sugars.

**Mash Complete (First Runnings)**

**Mash Complete (First Runnings)**

*Measurement:*Gravity - Sample taken from first runnings or directly from mash. Be sure to mix wort prior to taking gravity sample.

Volume - Wort volume from draining the mash to the kettle before any sparging.

Measures:

Lauter Dead Space: Amount of wort left behind in your lauter/mash tun.

Grain absorption rate: Amount of wort absorbed by the grain during the mash. Typical values are 0.5 qt/lb (0.125 gal/lb, 1.044 L/kg) for a mashtun, or 0.32 qt/lb (0.08 gal/lb, 0.66 L/kg) for biab with a squeeze or hanging to drain.

**Mash Complete (Last Runnings)**

**Mash Complete (Last Runnings)**

*Measurement:*Gravity - Sample taken from final runnings after sparging. Be sure to mix wort prior to taking gravity sample.

Volume - Wort volume from draining the mash to the kettle after any sparging. Should match sparge volume.

**Pre-Boil:**

**Pre-Boil:**

*Measurement:*Gravity - Sample taken at the start of the boil. Be sure to mix the wort prior to taking gravity sample, especially if you sparged. Alternatively let the wort boil for a few minutes.

Volume - Initial wort volume in the kettle.

Brew Log Type - 'Pre-Boil Gravity'.

Measures:

**Preboil Efficiency.**The percentage of sugars from the grain that made it into the kettle.The equation the system uses comes from Braukaiser's article on Understanding Efficiency. We believe this is the most accurate equation out there because of the 3rd term which accounts for the volume increase from the extracted sugars.

** Post-Boil:**

**Post-Boil:**

*Measurement:*Gravity - Sample taken at the end of the boil.

Volume - Final wort volume in the kettle after chilling.

Brew Log Type - 'Post-Boil Gravity'.

A duplicate log entry of Boil complete, but without affecting efficiency calculations.

**Boil Complete:**

**Boil Complete:**

*Measurement:*Gravity - Sample taken at the end of the boil.

Volume - Final wort volume in the kettle after chilling.

Brew Log Type - 'Post-Boil Gravity'.

Measures:

**Ending Kettle Efficiency.**The percentage of sugars from the grain that made it to the end of the boil.Ending Kettle Efficiency is the efficiency factor used on the recipe editor when batch size target is set to '

**Kettle**'.The equation the system uses comes from Braukaiser's article on Understanding Efficiency. We believe this is the most accurate equation out there because of the 3rd term which accounts for the volume increase from the extracted sugars.

Theoretically the same as Pre-Boil Efficiency, if there are no late additions during the boil, provided accurate measurements at both points (minus rounding error)

There is a corner case in all grain brewing, where an 'all grain' recipe includes raw sugar or extract. In this situation, the extract / sugar additions are expected to be in the wort at this point, thus increasing the gravity reading. The system excludes the gravity contribution from the sugar for the purposes of this calculation. This is not a typical situation in all grain brewing, but if you are adding some sugar to your IIPA, then you can still get useful numbers.

**Brew Day Complete:**

**Brew Day Complete:**

*Measurement:***Original Gravity**- Sample taken after transferring to fermenter, and before pitching yeast.Volume - Initial wort volume in the fermentor after cooling.

All losses that do not make it into the fermentor are counted against this measure, including hops absorption (which varies by recipe), chiller losses, and trub losses.

Measures:

**Brewhouse Efficiency.**The percentage of sugars from the grain that made it into the fermentor.Brew House Efficiency is the most common efficiency used, and is the efficiency factor used on the recipe editor when batch size target is set to '

**Fermentor**'.Brewday Complete log entries are included in the

**Fermentation chart**by default.

**Fast Ferment Test:**

**Fast Ferment Test:**

*Measurement:***Ending Gravity**- The ending gravity of the fermented wort at the end of the fermentation test.

Predicts:

**Final Gravity.**The purpose of a fast ferment test is to anticipate the final gravity, and attenuation, of the main batch.A Fast Ferment Test (FFT) is done by taking a small amount of unfermented wort from your recent brew session and quickly fermenting it down as far as it will go. The resulting FFT gravity reading provides a scientific basis for knowing when the batch it came from is done fermenting. FFT allows the brewer to make more informed decisions about when to package, if fermentation is stuck or not, etc.

For more information about fast ferment tests, check out Braukaiser's article on the Fast Ferment Test.

**Sample (fermentation): **

**Sample (fermentation):**

*Measurement:***Gravity**- The current gravity of the fermenting beer.**Temperature**- The current temperature of the fermenting beer.**pH**- The current pH of the fermenting beer.

Predicts:

**Final Gravity.**The purpose of a fast ferment test is to anticipate the final gravity, and attenuation, of the main batch.Sample log entries are included in the

**Fermentation chart**by default.

**Additional Information:**
Partial Mash Recipes - Pre-Boil Efficiency is not reported. This is because partial mash is a simplified brewing method that always includes extract or sugar.
The numbers do not always match up perfectly (even if you hit exactly what the recipe says), because the recipe editor uses non-rounded values for computations. See the ABV FAQ for more info about that.

### Alcohol and Attenuation

How does the brew session report ABV, and why doesn't it always match the recipe exactly even though I hit the same values?The system will calculate the actual ABV of your finished beer using gravity readings entered in the brew log. The ABV equation selected on the recipe is used to calculate the actual ABV. Read more about the equations here.
The numbers do not always match up perfectly (even if you hit exactly what the recipe says), because the recipe editor uses non-rounded values for computations. Even though the OG on the recipe reads 1.050, behind the scenes it could be something like 1.0504386. In some cases, this is enough to cause minor differences. You can experiment with this yourself by entering a gravity reading of 1.0504 in the brew log, and see the impact it has. The value will be rounded to 3 places in the log listing, but the detail is retained in the system.
We feel it is better to avoid rounding until the end inside the software, and live with the limitations of hydrometer scale resolution when calculating actual ABV.
**For ABV and attenuation to be reported, enter a 'Brew Day Complete' log, and a 'Fermentation Complete' log.** By entering 'Sample', or 'Racked' log entries, the system will calculate the latest attenuation and ABV. The green checkbox will not be filled in until a 'Fermentation Complete' log is provided.

## Brew Log

Brew log entires can show up on your fermentation chart.

### Add Log Entry

Click add log entry to create a log entry.

### Event

Events marked as `Fermentation Chart`

will be plotted on the fermentation chart.

Mash Complete

Pre-Boil Gravity

Boil Complete

Brew Day Complete

`Fermentation Chart`

Fast Ferment Test

`Fermentation Chart`

Sample

`Fermentation Chart`

Racked

`Fermentation Chart`

Fermentation Complete

`Fermentation Chart`

Packaged

Tasting Note

Other

Yeast Starter

### Gravity

The system also supports Refractometer readings. The brew log entry screen is setup to correct the raw reading in two important ways:

A wort correction factor must be applied that accounts for the refraction difference between sugar water and wort. To help clear up confusion with terminology, at Brewer's Friend we have decided to call a Brix measurement of wort: Brix WRI (wort refraction index). Brix WRI makes it clear the measurement pertains to wort and is unadjusted. Only after dividing Brix WRI by the wort correction factor do we arrive at the actual Brix / Plato reading. It is helpful to know that Brix and Plato are nominally the same to 3 decimal places, so the corrected reading can be treated as Plato (°P). The wort correction factor is an equipment profile option. Click here for our detailed write up on how to determine a refractometer's wort correction factor.

If alcohol is present it alters the refraction by an additional factor. An equation which requires the OG must be used to correct the refractometer reading. The system displays an 'OG' box and fills in the OG automatically from your brew log. The calculator uses Sean Terrill's cubic equation.

For more information about refractometer use in general: Using your Refractometer Correctly for Maximum Accuracy in Home Brewing.

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