Brew Sessions

What does a brew session track?

A brew session tracks when you brewed a given recipe, the actual original gravity, the actual final gravity, and any log events you want to record in addition. Log events should be rich comments that describe any process changes you made, fermentation temperature range, tasting notes, smells, etc.

The brew session uses your log entries to automatically calculate actual ABV, actual attenuation, and efficiency.

What is a snapshot recipe?

A snapshot recipe is a special copy of a recipe tied just to the brew session it goes with. This is very handy if you take a slight detour on brew day, or make a substitution from the original recipe, but you don't want to bother with making a full copy of the original.

How do the water volume calculations work?

The system takes your equipment profile and processes the recipe to calculate how much water is needed at each step. The first time you may need to fine tune your equipment profile, then use the Brew Session -> Edit -> Rebuild Steps feature to have the water volumes recalculated.

Does the brew session support BIAB?

Yes. The water calculations are done for you, and the mash feature understands a mash tun is not involved.

For gravity readings, how are hydrometers supported in terms of calibration and offset?

When taking a gravity reading, the wort temperature can skew the reading. The hotter the wort, the less accurate the reading.

On the Brew Log entry screen there is a field for the temperature of the sample. The system uses this value to compute the actual gravity.

To complicate matters, there are two popular calibrations (59F/15C, and 68F/20C). You can enter your hydrometer's calibration when you make the log entry. This is a profile option under the equipment tab.

Some hydrometers are not calibrated correctly from the factory and read slightly off from 0.000 in water at their calibration temperature. The system lets you correct for this on the Brew Log entry screen, and this is also a profile option.

You may enter the gravity in either Plato or Specific Gravity. The system supports temperature correction, calibration, and offset for both scales.

How is efficiency calculated in a Brew Session?

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

1) Conversion Efficiency:

The percentage of total available sugars that were extracted from the grains inside the mash tun.

  • Brew Log Type - 'Mash Complete'.

  • Measurement Option A - first runnings:

    • Gravity - sample taken from first runnings.

    • Volume - strike water used (count all water added to the MLT before the sample was taken).

    • Generally, only accurate for recirculated mash systems.

  • Measurement Option B - blend of runnings:

    • Gravity - sample taken before the boil, blend of all runnings.

    • Volume - how much water went into the MLT, counting strike and sparge water.

    • Note: With Option B, the wort sample must be fully blended from all the runnings to be accurate. First runnings have a higher gravity than second runnings.

    • Best option for batch spargers. Works for BIAB and partial mash (MLT and kettle are the same).

  • 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.

2) Pre-Boil Efficiency:

The percentage of total available sugars that made it into the kettle.

  • Brew Log Type - 'Pre-Boil Gravity'.

  • Gravity - measured before the boil, blend of all runnings.

  • Volume - how much wort went into the kettle.

  • Volume losses from mash tun dead space and grain absorption count against this measure.

3) Ending Kettle Efficiency:

The percentage of total sugars in the kettle after the boil. Theoretically the same as Pre-Boil Efficiency, provided accurate measurements at both points (minus rounding error).

  • Brew Log Type - 'Boil Complete'.

  • Gravity - OG, measured after cooling, before pitching yeast.

  • Volume - ending kettle volume when cooled, before draining.

  • Kettle dead space, trub losses, and hops absorption do NOT count against this measure.

  • 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 solid numbers.

Ending Kettle Efficiency is the efficiency factor used on the recipe editor when batch size target is set to 'Kettle'.

4) Brew House Efficiency: An all inclusive measure of efficiency, which counts all losses to the fermentor. This can be thought of as 'to the fermentor' efficiency.

  • Brew Log Type - 'Brew Day Complete'.

  • Gravity - OG, measured after cooling, and before pitching yeast.

  • Volume - how much wort made it into the fermentor.

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

Brew House Efficiency is the efficiency factor used on the recipe editor when batch size target is set to 'Fermentor'.

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.

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.

How does the Mash Calculator tab work?

The Mash Calculator tab helps track the mash as it happens in terms of volume and temperature. The first step is to add the strike water and start the mash - please see the Strike Water FAQ for more on that.

Batch Sparging - basic procedure for a 2 step sparge:

  1. Add Strike Water

  2. Use the Infuse or Add Boiling tab to hit rest steps, or to adjust as needed

  3. Drain to Kettle (1st runnings)

  4. Batch Sparge Tab - infuse remaining mash water

  5. Drain to Kettle (2nd runnings)

The system will only count grain absorption and mash tun dead space on the first 'drain to kettle' step!

Fly Sparging:

  1. Add Strike Water

  2. Use the Infuse or Add Boiling tab to hit rest steps, or to adjust as needed

  3. Fly sparge - automatically accounts for grain absorption and mash tun dead space, and allocates the remaining volume to the kettle.

For RIMS / HERMS brew rigs:

  1. Add Strike Water

  2. Raise Temp / Record Temp for any rests

  3. Batch sparge then drain to kettle, or fly sparge


  1. Add Strike Water

  2. That's it since you are mashing with enough water to hit your pre-boil volume after pulling out the grain bag.

Temperatures are Estimates: Keep some cool and boiling water on hand to make small adjustments as necessary. Record any cool or boiling water added to the mash using the Infuse / Add Boiling tabs. You may also add comments to the mash log under the comments tab on the left.

Brewing In A Cold Area: The equations powering this feature are geared for room temp (68 °F / 20 °C). If you are brewing in a cold area, compensate accordingly. For example, if the ambient temperature is 45 °F / 7 °C, we recommend padding by up to +10 °F / +5.5 °C. Better to overshoot a few degrees and leave the lid open vs having to add boiling water to heat it up.

Additional Information: The water volume estimate comes from the Water Requirements tab, and uses settings from your equipment profile to compute how much water will be needed. If you change your profile options, go the Brew Session - > Edit tab, and click Rebuild to regenerate the water requirements table.

Mash steps from the recipe are provided at the bottom of the Mash Calculator tab for reference. The data from the mash steps does not factor into the calculations, except as defaults where the system can pick them up.

How does the Strike Water calculator work?

The Strike Water calculator, located under the Mash Calculator tab, helps you hit the temperature of your first mash step.

This calculator is approximate. After initial strike and stir, if the temperature is +/- (2 °F) / (1 °C) leave it. Otherwise mix in cool or boiling water to compensate. Use the Infuse or Add Boiling tab to track how much was added. If the temp is only slightly over, leave the mash tun lid open for a couple minutes and it will cool down by itself.

If this is new equipment or your first time mashing with this calculator, expect some variation. It should get at least within 7 °F / 3.5 °C, if not closer, after adjusting the heat loss setting. Please see the FAQ for more details:

At this point the equation is basic, based off Palmer's equation found here. It works best for batch sparging. The limitations come from a single equation trying to model everyone's equipment (mash tun thermal properties), and varying processes. Adjust the Mash Strike Heat Loss setting in your profile as needed. Expect it to take a couple tries to dial it in.

NOTE: The strike calculator assumes your tun will absorb heat (a few degrees will be absorbed by the mash tun, this varies widely by the type of mash tun). Even if you 'pre-heat' the tun with a little boiling water, this may still be the case. Do not stabilize the tun at the calculated strike temperature, and then add grains, or you will probably overshoot.

Brewing In A Cold Area: The equations powering this feature are geared for room temp (68 °F / 20 °C). If you are brewing in a cold area, compensate accordingly. For example, if the ambient temperature is 45 °F / 7 °C, we recommend padding by up to +10 °F / +5.5 °C. Better to overshoot a few degrees and leave the lid open vs having to add boiling water to heat it up.

When I create a brew session, will it deduct from my Inventory?

Yes, if you want it to. You even get the chance to override any values and select which lines to deduct before submitting. You may deduct from inventory when you create the brew session, or anytime after that by going to the Brew Session -> Edit tab and locating the Deduct From Inventory section.

The system uses the following comparison logic for matching inventory items with recipe ingredients:

  • Fermentables and Steeping Grains: name, ppg, lovibond.

  • Hops: name, aa, type.

  • Yeast: laboratory, name.

  • Other Ingredients: name.

  • Only inventory items with an amount greater than zero will be matched.

If your inventory does not have quite enough to cover a given recipe requirement, a negative value will be shown (in fact, the system will tell you the exact amount you are short by). If the negative value is left in place, when you submit, that inventory line will be updated to zero.

The Inventory Deduction feature supports a wide variety of unit conversions. This allows you to keep inventory amounts in the units you prefer, while the recipe may use alternate units. Even rare conversions like Liters to Teaspoons is supported.

  • The following weight units are interchangeable: Pounds, Ounces, Kilograms, Grams.

  • The following volume units are interchangeable: Ounces, Liters, Milliliters, Quarts, Gallons, Tsp, Tbsp.

  • Note that ounces appears in both lists, make sure you know which type of ounce you are dealing with.

  • The unit Each only converts to itself.

  • The system will provide a 'Cannot Convert X to Y' warning if a match is found but the units are not compatible. At that point, override the default value provided to the correct amount.

If the same ingredient is listed more than once in the recipe the system will group that ingredient in the inventory deduction table. Example - an extract batch that does 50% of the DME as a late addition.

Current limitation - the matching logic does not support the same inventory item being listed twice. This is generally only an issue if you have hops spanning multiple harvest years, or you have entered the same ingredient with different units, or you are trying to track the same item across different containers. At present the system will only draw from the first matching inventory line it encounters. Later on, if requested, we can look into expanding the logic so it handles this situation.

Does the system correct for water/wort volume expansion?

Yes. When you enter a brew log, you have the option of entering the wort temperature (check the 'Temperature Correction' box). The system will compute the volume as if it were at 68 °F / 20 °C.

When water is heated, it expands. Typically a 4% decrease in volume is observed when going from boiling to 68 °F / 20 °C. The percentage can vary with elevation. The system uses your Cooling Shrinkage profile option in the calculation.

The equation used is linear. The floor is set at 68 °F / 20 °C, so it will not compute adjustments below that temperature, but they are negligible.

Does the system support a Fast Ferment Test and what is it for?

Yes. 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.

In the brew log for a brew session, add a 'Fast Ferment Test' type log entry with gravity reading from the test after it has fermented down. The system will report the expected attenuation and ABV for the batch.

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

Does the system have brew timers?

Yes and they are automatically setup to match the recipe and your brewing process. After creating a brew session, look for the black bar at the bottom of the screen and click the 'Open More...' button.

As you check off steps, the rows in the Brew Steps tab above will also be checked off. Certain steps get timers, like mash steps, the overall boil, and kettle additions. The system looks for hop additions, other ingredients marked as 'boil', and incorporates other items like submersing your chiller (if applicable) and sanitizing the lid of your kettle. The timers are saved in the system, so if you leave the page and come back, they will still be running.

When a step timer hits zero, a sound will play. The sound that currently plays is called Timer by Corsica_S at

The black bar at the bottom automatically disappears after advancing past the Brew phase.

What gravity scales are supported for recording gravity on brew log entries?

We support Specific Gravity (, Plato °P, and Refractometer readings (which we call Brix WRI).

Specific Gravity and Plato measurements are normally taken with a hydrometer. The screen displays a temperature correction checkbox, see this FAQ for more information about hydrometers and temperature correction.

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

  1. 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.

  2. 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.

Can I get a report of my brewing activity?

Yes, look for the Brewing Report link on the Dashboard or under My Brewing -> Brewing Report.

The report can be filtered date range. The dates are optional. The data powering the report is derived from your brew sessions and associated recipes (snapshots recommended). Note: The report excludes brews that are still in the planning phase and deleted brews.

The report summarizes your brewing in the following ways:

  1. How much beer was brewed total for the time period.

  2. A count of which styles were brewed.

  3. A detailed ingredient summary which shows how much of each ingredient was used. Allows drilling down to see which recipes used how much of each ingredient.


Editable Brewing Steps

Our default brew steps are generated when you click the "brew" button and create a brew session. That works well for many brewers and we suggest you start there when using Brewer's Friend. Over time, you may find that you don't need to be told to "gather your equipment" or other steps that you don't use and you can delete those from the Brew Steps.

To customize your Brew Steps, log into your account and choose "my profile" in the "My Brewing" choice on the tool bar. Brew Steps is one of the choices in the boxes near the top of that screen. Click on that box. The brew steps are shown, in all grain steps, partial mash steps, BIAB steps, and extract steps. The chosen steps are shown with a green check mark. Check or uncheck the steps as desired. Click "apply" at the very bottom of this screen, by scrolling to the bottom. Your chosen steps will be the ones that show in your Brew Log and Brew Steps on your brewsheet.