Recipe Formulation with Water Calculations

In this post, we will formulate a new recipe and calculate the needed water amounts at the same time. This is not a big deal since the only real water change is the amount of water absorbed by the grains. Because we do not yet know the amount of grains we will use, we calculate the water from the target batch size back until we get to the water absorbed by the grains. At that point, we are able to calculate our grain amounts and then complete the water calculations. Rather than just talk about this process, I want to demonstrate the steps needed so that it serves as a complete example for reference.

Before moving on, I feel I need to make something clear: The Original Gravity (OG) and Final Gravity (FG) measurements are both taken from my fermenter. The OG is measured prior to adding the yeast for fermentation, and the FG is measured after fermentation has completed. This is important, and I did not make this distinction previously which could lead to some confusion when talking water amounts used in calculations.

OK, I am excited about this recipe because it is a first attempt at cloning my favorite beer: Goose Island's Bourbon County Stout. In this post, I do not want to get into my feelings towards the InBev purchase of Goose Island, so I will just summarize that my initial optimism and acceptance was turned sour by the discovery/learning of the unscrupulous InBev corporate views of the craft beer industry and their unethical business practices. So, all the better if the beer can be replicated at home. On to the recipe....

As I mentioned, I am excited to try and brew this beer, but the recipe guidelines are not from me. The grains and hops used are from the Goose Island description linked above; The gravity values used are from a post in the HomeBrewTalk forums (using the 2007 version of the beer); The grain percentages used are also from a post in HomeBrewTalk. Here are the specifics we are using:

Recipe Parameters

Parameter	Value
Batch Size (fermenter volume)	3.25 gal.
Target Original Gravity	1.13
Target Final Gravity	1.042
Color	Black ~100 SRM
IBU	60 (assume Tinseth method)
Length of Boil	80 min.
Mash Steps	Single infusion 152°F for 60 min.
Brewhouse Efficiency	70%

Grains

Grain	% Used	Max Extraction	Color (°L)
2-Row	34	37	1.8
Munich	30	34	10
Chocolate	14	34	350
Crystal 60	10	34	60
Roast Barley	10	25	300
Debittered Black (Briess Blackprinz)	2	25	500

Hops

Willamette 3.5% to 6.0% AA @60 min. ~4 oz. (TBD)

Yeast

Safale US-05 Dry Yeast 3 packets

STEP 1: Calculate Initial Water Amounts

Remember that the constants used in finding water amounts are specific to my system. Your values may be different. In some cases they are just guesstimates waiting for me to collect more accurate information

• V_final = 3.0 gal (amount in bottles or keg)
• bottling losses: ~ 0.25 gal.

• V_fermenter = 3.25 gal.
• Transfer and trub losses: ~0.75 gal.

• V_post-boil = 4.0 gal.
• Temperature shrinkage: 4% ~ 0.2 gal.
• 80 minute boiloff: 2.34 gal.

• V_pre-boil = 6.5 gal.

This is as far as we can get without knowing the grain amounts.

STEP 2: Estimate Grain Amounts

To summarize the values of interest here:

• Original Gravity: 1.13 (130 Gravity Points)
• V_fermenter : 3.25 gal.
• Brewhouse Efficiency: 70%

     ► Total Gravity (GT)

GT = Gravity Points * Volume

GT = 130 * 3.25

GT = 422.5

This is the total number of gravity points in our fermenter that we need to be contributed by the grains.

     ► Individual Grain Contributions to Total Gravity

Here we use the percentage of each grain used to determine the amount of gravity points each individual grain contributes.

Grain	Percent Calculation	Grain Contribution
2-Row	0.34 * 422.5	143.6
Munich	0.30 * 422.5	126.7
Chocolate	0.14 * 422.5	59.2
Crystal 60	0.10 * 422.5	42.25
Roasted Barley	0.10 * 422.5	42.25
Blackprinz	0.02 * 422.5	8.5

     ► Grain Amounts Needed to Achieve Gravity

Now we use the individual gravity contributions, the maximum gravity that can be extracted from the grain and our brewhouse efficiency to find the grain amount. Here is the equation used:

Grain Gravity Contribution / (Brewhouse Efficiency * Max Extract Points)

Grain	Formula	Value (lbs)	Value (lbs And oz)
2-Row	143.6 / (0.7 * 37)	5.5 lbs.	5 lbs. 8 oz.
Munich	126.7 / (0.7 * 34)	5.3 lbs.	5 lbs. 5 oz.
Chocolate	59.2 / (0.7 * 34)	2.5 lbs.	2 lbs. 8 oz.
Crystal 60	42.25 / (0.7 * 34)	1.8 lbs.	1 lbs. 13 oz.
Roasted Barley	42.25 / (0.7 * 25)	2.4 lbs.	2 lbs. 6 oz.
Blackprinz	8.5 / (0.7 * 25)	0.5 lbs.	0 lbs. 8 oz.
TOTAL:		18 lbs.	18 lbs. 0 oz.

STEP 3: Calculate Remaining Water Amounts

We now continue where we left off calculating our water amounts. Our last calculation was for the pre-boil volume, so we start there:

• V_pre-boil = 6.5 gal.
• Transfer loss: ~0.25 gal.
• Grain Absorption: 18.0 lbs. * 0.2 gal./lb. = 3.6 gal.

• V_total = 10.35 gal. ≈ 10 gal. 1.5 qt.
  
  

STEP 4: Calculate Mash and Sparge Volumes

For my mash, I am going to use 1.3 quarts of water per pound of grain. Also, remember that I have a full 4 quarts of space under my false bottom in my mash tun, so that needs to be added to the mash water.

V_mash = 1.3 qt/lb * 18.0 lbs + 4 qt

V_mash = 27.4 qt ≈ 6.85 gal. = 6 gal. 3.5 qt.

The sparge volume is now just a matter of subtracting the mash volume from the total volume.

V_sparge = V_total – V_mash

V_sparge = 10.35 gal – 6.85 gal.

V_sparge = 3.5 gal. = 3 gal. 2 qt.

Since I doubt I am 100% correct, I will make sure I have probably 5.0 gallons of sparge water available. I will just need to make sure I hit the proper volume in my boil kettle while watching the gravity readings of my runnings.

Conclusion and Remaining Information Needed

So that is it for calculating our grains and water. Of course, there is some information missing in regards to brewing the recipe:

1. We really didn't do anything with the hops. We know the IBU we need to hit, and I mentioned that we are using the Tinseth method for IBU calculations. Through that, we can estimate our hop amounts (it also depends on the actual %AA of the hops you purchase). Maybe this will be my next post.
2. Based on the gravity and volume amounts, I believe the 3 packages of dry yeast will be sufficient for this big beer. One thing we did not cover is the fermentation schedule (times and temps). This will definitely be racked to a secondary fermentation where we will allow the beer to sit on bourbon-soaked oak cubes for probably 6 months. I am not 100% sure, but I will probably let this sit in primary for two weeks; with week one being at a cooler temperature of maybe 60 degrees or so, and the second week at around 68 degrees. The secondary will be 6 months, and that temperature will probably be the same 68 degrees (not a lot of options for my basement).
3. Speaking of bourbon-soaked oak cubes, how much bourbon and how many cubes? Since we only have 3 gallons, I am assuming one 1 ounce cube. As far as the bourbon, I am not sure yet (amount or brand). I used Makers Mark and oak chips for my last beer and was less than happy, so this time I am moving to cubes and some other bourbon brand.

So these are questions that still need to be answered, but we are well on our way to making a first attempt at our clone. If this recipe doesn't work out, we get to drink what will probably still be a great beer and then try again. If it does work, we make more. Truly a win-win.

Calculating Water Amounts

Introduction

This post is going to be about calculating the amount of water needed to brew a specific volume of beer  using a specific amount of grains on my specific system.  This is important because everyone's system is different.  This is the reason for the previous post where I calculated specific values for my system - values that will be used in my water amount calculations.  Before calculating my water amounts, let me quickly go over the details/reasons for my brewing posts....

Reason for Brewing Posts

I believe I mentioned this previously, but let me again state that these posts are not a basic step-by-step how to brew.  There are plenty of great resources for this, and I think the best place to start is with Palmer's book How To Brew.  This book is great for both the beginning brewer and the advanced brewer.  In fact, I am writing these posts because there is so much information out there.  I read enough to successfully brew a couple of batches of beer, and now I need to advance towards brewing better.  I am not an expert, but I am simply detailing my journey of trying to become one.  My hope is that someone smarter will correct my mistakes and answer my questions.

Some of the topics I intend to cover are water amounts needed to brew, how to formulate a recipe, calculating efficiencies, yeast starters, equipment and software tools, water reports, water modifications and possibly even writing my own software tools.  Hopefully we will all learn something as we go along (otherwise this is a complete waste of time when I could be brewing instead).

On to Calculating Water Amounts...

So I have brewed two batches of beer so far.  They were both supposed to be five gallons and they were both short on that amount.  I don't even want to count my first batch since it really was a learning batch; trying to put into practice the loads of information I had crammed into my poor brain.  I learned a lot - mainly information in the "what not to do" category.

So let me go through my water calculation that I have created.  I will know how accurate this is when I brew my next batch, and I will post those results at that time.  For now, here are the parameters we have:

• Target Batch Size: 5 gallons
• Total Grain Weight: 9.5 pounds
• Boil Time: 80 minutes

From the previous post, we saw that during a 60 minute boil, I will lose 1 gallon and 3 quarts or 7 quarts per hour.  If I divide the 7 quarts by 60, I will get the number of quarts per minute:

7 qt. / 60 min. = 0.117 qt/min

So if I have an 80 minute boil, I should lose:

80 min * 0.117 qt/min = 9.36 quarts or about 2.34 gallons

OK, so let's start with our final target volume and start moving backwards through the process.  We are interested in tracking the following volumes: Final volume (Vfinal), Volume in fermenter (Vferment), Volume post-boil (Vpostboil), Volume pre-boil (Vpreboil), Total volume needed (Vtotal).

Vfinal = 5 gal.

• Add any beer lost while bottling.  This is any beer caught in the settled yeast and equipment dead space.  I am guessing at this number, and will need to adjust this number based on observations when I brew.  For now, I am assuming 0.25 gallons.

Vferment = 5.25 gal.

• Add water lost to trub and hops in the boil kettle as well as transfer losses between boil kettle and fermenter.  I am guessing with the trub and hop losses with a value of 0.5 gallons.  My system tests showed that I lose about 0.25 gallons pumping from my kettles.  So total loss here is 0.75 gallons.

Vpostboil = 6.0 gal.

• Add adjustment for temperature shrinkage.  It seems water occupies a different volume at higher temperatures so we need to adjust for this.  I cannot claim that I totally understand this, but I am using (trusting) the value described in Ray Daniels book Designing Great Beers page 65: divide by 0.96.  Therefore, 6.0 / 0.96 brings us to a total of 6.25 gallons.
• Add the water lost in the boil (2.34 gallons) to the 6.25 gallons.

Vpreboil = 8.6 gal. = 8 gal. 2 1/2 qt.

• Add water lost in transfer from mash kettle to the boil kettle (0.25 gal from system measurements)
• Add water lost to grain absorption.  Here again, I put my trust in Ray Daniels and assume about 0.2 gallons per pound of grain gets absorbed: 0.2 gal/lb * 9.5 lb. = 1.9 gal.

Vtotal = 10.75 gal. = 10 gal. 3 qt.

I am using a total of 10.75 gallons of water, but I will mash with some smaller amount and sparge with the rest.  I use the fly-sparge technique.  If you batch sparge, then you will want to look into he optimal size for the number of runnings you perform.

When I mash, I will be using the ratio of 1.5 quarts per pound of grain:

1.5 qt/lb * 9.5 lb = 14.25 qt.

BUT, remember from my system measurements that I have a full gallon of water that sits below my false bottom in my mash kettle.  Therefore I need to add this amount (4 quarts) to my mash water: 14.25 qt + 4.0 qt = 18.25 qt.

Mash Water: 18.25 qt. = 4 gal. 2 qt.

Once I know my mash water amount, I simply subtract that from the total water to get my sparge water amount: 10.75 gal - 4.5 gal = 6.25 gal.

Sparge Water: 6.25 gal. = 6 gal. 1 qt.

So it is doubtful we have the exact amount of water, so to be safe I will actually make sure I have 7 gallons of water for my sparge - or perhaps place 12 gallons of total water in my HLT before removing the mash water amount (I initially place all water in my HLT so that I can use a campden tablet to remove the chloramine - but that is for a future post).

This should be a good first estimate.  Values will get tweaked as I gain a better insight during the brew process.  So this works great when you know the total amount of grains you are using.  What about when you are designing a recipe?  When calculating water, you need to know the amount of grain.  When creating a recipe, you need to know the amount of water.  How do you calculate the two together?  This will be addressed later.  First we will go through recipe formulation and then tie that together with calculating the water amounts.

Brewing System Information

In order to understand my processes and equations later, I need to cover some details now.  As I mentioned, I am using the 15.5 gallon Ruby System.  Here is an image from their website:

The Hot Liquor Tank (HLT) feeds hot water into the Mash/Lauter Kettle (MK) via gravity.  The HLT merely holds hot water used for dough in and sparge - I actually add my grains directly to water in the MK, so the HLT is only used to hold sparge water.  The MK uses the pump for recirculation of the wort as well as transfer to the Boil Kettle (BK).  The BK also uses the pump for recirculation (to sanitize the hoses and pump as well as assist in cooling via an immersion chiller) and transfer of wort to my primary fermentation (6.5 gallon glass carboy).

Each kettle is the same size, but the MK and BK both contain a false bottom:

In the next post, I will go through my calculated water amounts.  Before determining the amounts, I had to run through some tests on my system:

Test 1: Find losses when pumping water from one kettle to another.

• Basically I just put 2 gallons in my MK and then pumped the water to the BK.  The result was a loss of 1 quart.

Test 2: Find losses from boiling for one hour.

• Just as the test suggests, I filled a kettle with 3 gallons of water and boiled it for one hour.  Keep in mind that I am at about 5400 feet in South Denver, Colorado.  The result was a loss of 1 gallon and 3 quarts.

Test 3: Find how much water exists under the kettle's false bottom.

• I added water 1 quart at a time.  The result was that a full gallon of water exists under the false bottom

There are more tests that could have been done, but as you will see in the next post, I will use some pre-calculated constants instead.  That is it for now.  Next time we will use these numbers to figure out how much water I need to brew a batch.