If you scan the last year of posts on this weblog, you won't find many progress updates. That's because all Jane and I have done since January, aside from finding a location, is try to raise money. So far, we've only been able to raise about 10% of our project cost via investment capital - including our own contributions - and were rejected by eleven lenders (not counting the ones who ignored us). We considered some alternative business plans...

-Reducing the structural changes to the ACME building and replacing the full kitchen with cold appetizers to reduce the total project cost.

-Relocating to the former Blue Lagoon building to reduce the total project cost, allow us to have a full kitchen and provide an incentive for the Bank of Sun Prairie to loan us money (they own the building, which is now completely vacant).

-Relocating to Sauk Prairie, where there may have been additional investment capital.

...but my need to find a job and stabilize my family's finances hasn't allowed me to really follow through on them. Being burnt out hasn't helped either. After two years of working full-time to get this project off the ground, every option seemed like a futile postponement of my brewing career.

The point I'm slowly making is that I'm cutting my losses and walking away from RePublic. Earlier today, I accepted a job offer for a full-time brewing position at Fratello's in Oshkosh and Appleton. I'll be working for Kevin Bowen, a classmate of mine from Siebel, and I'm pretty damn excited about it. Jane is hoping to find a job in a brewery as well; probably in sales and/or marketing. This industry is simply too much fun to walk away from willingly.

Unless I think of some wise things to say over the next few days, this will probably be the last time I post here. Jane and I are going to leave the site online so future brewery owners can benefit from our experience, and I plan to continue updating the File Cabinet independently. Thanks for reading!

Update: I'm currently the QA Manager at Ale Asylum and write the Five Gallons At A Time feature at Madison Beer Review. In between, I wrote a few articles for Oshkosh Beer that you can find by searching for my name on the website. Jane, aka Robyn Klinge, left her job at Epic Systems to bartend, manage off-premise tap accounts, train employees about beer and host beer dinners at Vintage Brewing Company.

## Saturday, November 21, 2009

## Saturday, November 7, 2009

### Return to Geekery

About two weeks ago, my Vermonting friend Shane asked me a question that I thought would be pretty easy to answer: about how much alcohol is present in a batch of cider when honey is added after the original gravity measurement? Estimating the sugar increase is a pretty easy process. Figuring out the change in volume, which affects the density that affects the alcohol content, is the tough part. Thankfully, my recipe spreadsheets are capable of doing that. Unfortunately, the numbers they returned didn't agree with a simple sanity check I performed to make sure I was doing things correctly. The problem, I eventually learned, was caused by several errors:

1. The formula I'd been using to calculate extract, aka the weight of dissolved sugar, didn't agree with the definition of degrees Plato (extract as a percentage of total solution mass). I'm bummed out by this because the formula's source is the wonderful book "Brewing" by Michael Lewis and Tom Young. If you're dying to find a practical use for an outdated formula, the calculation is Extract = (258.7+degrees Plato)*degrees Plato*barrels/100. If you've wiped your nose with this stuff before, you may have noticed that 258.7 is the density of water, in lbs/barrel, at 39.2 degf. The American Society of Brewing Chemists (ASBC) defines degrees Plato at 68 degf. Reaching for that low-lying fruit by changing the value in the formula was one of the first things I tried. It didn't work.

2. Homebrewers typically measure gravity in Specific Gravity instead of degrees Plato. Additionally, disowning the degrees Plato -> Extract formula requires you to know specific gravity to determine extract. My prior conversions between degrees Plato and specific gravity were third-order polynomials fitted to an ASBC table, but the table is only valid for specific gravities of 1.083 (20.007 degrees Plato) and lower. Not terribly helpful when you're brewing a barleywine, and downright inaccurate when you're trying to determine how adjuncts like honey (gravity of 82.1 degrees Plato for the Wikipedian varietal) affect final liquid properties.

3. I was calculating all of my adjunct additions based on a parameter called "total wort volume", which was essentially the post-boil volume plus the volumes of any adjuncts added afterward (i.e. a yeast starter). Another way of thinking about it is that total wort volume = initial fermentation volume plus kettle wort losses. It's a made-up variable that never physically exists, but I thought it was a clever way to manage the interactions of several adjuncts. The problem? When you add an adjunct to the boil kettle, you lose some of it. When you add it directly to the fermenter, you don't. Since I typically specify adjunct additions as percentages of total extract, equating them to percentages of total wort volume is invalid.

I solved issues #1 and #3 by calculating the degrees Plato, specific gravity, volume, mass and extract for every stage of the brewing process and using those values where applicable instead of using total wort volume everywhere. To do so, I needed to "fix" problem #2 by adding an endpoint to the ASBC table. Since sucrose has a density of 1.587 g/mL and water has a density of 0.9982 g/mL at the ASBC reference temperature of 20 degc, the specific gravity of sucrose is 1.587 / 0.9982 = 1.589. Since degrees Plato is defined as % sucrose by weight, 100 degrees Plato should equal 1.589. One of the curve fits is shown below:

I say "fix" because I don't actually know what the data looks like between 20 degrees Plato and 100 degrees Plato. At least the curve converges on a reasonable endpoint, which is good enough for government work. Here's how the process works for Shane's cider example (5.0 gallons of cider at 1.052, 4.8 lbs of honey with an assumed gravity of 82.1 degrees Plato, final gravity of 1.004):

1. Water density at 68 degf = 0.9982 kg/L = 8.3316 lbs/gal.

2. Initial cider mass = density*volume = (SG*Dwater)*volume = (1.052*8.3316)*5 = 43.8 lbs. Leave me alone about using lbs as a unit of mass; it's a lot easier than slugs.

3. Initial cider gravity = ((116.716*SG-569.851)*SG+1048.046)*SG-594.914 = 12.9 degrees Plato.

4. Initial cider extract = (degrees Plato/100)*mass = (12.9/100)*43.8 = 5.6 lbs.

5. Honey extract = (82.1/100)*4.8 = 3.9 lbs.

6. Total mass = cider mass + honey mass = 43.8 + 4.8 = 48.6 lbs.

7. Total extract = cider extract + honey extract = 5.6 + 3.9 = 9.6 lbs (5.64 + 3.94 = 9.58, which gets rounded up).

8. Original gravity = 100*extract/mass = 100*9.6/48.6 = 19.7 degrees Plato.

9. Final gravity = ((116.716*SG-569.851)*SG+1048.046)*SG-594.914 = 1.0 degrees plato.

10. Alcohol by volume = 0.516*(original gravity - final gravity) = 0.516*(19.7-1.0) = 9.6%. It should be noted that calculating alcohol content is always approximate; to determine the exact value, you need to perform a distillation test on a physical sample.

Thanks for the mental workout, Shane. Updated recipe and brewlog spreadsheets can be found in the file cabinet.

1. The formula I'd been using to calculate extract, aka the weight of dissolved sugar, didn't agree with the definition of degrees Plato (extract as a percentage of total solution mass). I'm bummed out by this because the formula's source is the wonderful book "Brewing" by Michael Lewis and Tom Young. If you're dying to find a practical use for an outdated formula, the calculation is Extract = (258.7+degrees Plato)*degrees Plato*barrels/100. If you've wiped your nose with this stuff before, you may have noticed that 258.7 is the density of water, in lbs/barrel, at 39.2 degf. The American Society of Brewing Chemists (ASBC) defines degrees Plato at 68 degf. Reaching for that low-lying fruit by changing the value in the formula was one of the first things I tried. It didn't work.

2. Homebrewers typically measure gravity in Specific Gravity instead of degrees Plato. Additionally, disowning the degrees Plato -> Extract formula requires you to know specific gravity to determine extract. My prior conversions between degrees Plato and specific gravity were third-order polynomials fitted to an ASBC table, but the table is only valid for specific gravities of 1.083 (20.007 degrees Plato) and lower. Not terribly helpful when you're brewing a barleywine, and downright inaccurate when you're trying to determine how adjuncts like honey (gravity of 82.1 degrees Plato for the Wikipedian varietal) affect final liquid properties.

3. I was calculating all of my adjunct additions based on a parameter called "total wort volume", which was essentially the post-boil volume plus the volumes of any adjuncts added afterward (i.e. a yeast starter). Another way of thinking about it is that total wort volume = initial fermentation volume plus kettle wort losses. It's a made-up variable that never physically exists, but I thought it was a clever way to manage the interactions of several adjuncts. The problem? When you add an adjunct to the boil kettle, you lose some of it. When you add it directly to the fermenter, you don't. Since I typically specify adjunct additions as percentages of total extract, equating them to percentages of total wort volume is invalid.

I solved issues #1 and #3 by calculating the degrees Plato, specific gravity, volume, mass and extract for every stage of the brewing process and using those values where applicable instead of using total wort volume everywhere. To do so, I needed to "fix" problem #2 by adding an endpoint to the ASBC table. Since sucrose has a density of 1.587 g/mL and water has a density of 0.9982 g/mL at the ASBC reference temperature of 20 degc, the specific gravity of sucrose is 1.587 / 0.9982 = 1.589. Since degrees Plato is defined as % sucrose by weight, 100 degrees Plato should equal 1.589. One of the curve fits is shown below:

I say "fix" because I don't actually know what the data looks like between 20 degrees Plato and 100 degrees Plato. At least the curve converges on a reasonable endpoint, which is good enough for government work. Here's how the process works for Shane's cider example (5.0 gallons of cider at 1.052, 4.8 lbs of honey with an assumed gravity of 82.1 degrees Plato, final gravity of 1.004):

1. Water density at 68 degf = 0.9982 kg/L = 8.3316 lbs/gal.

2. Initial cider mass = density*volume = (SG*Dwater)*volume = (1.052*8.3316)*5 = 43.8 lbs. Leave me alone about using lbs as a unit of mass; it's a lot easier than slugs.

3. Initial cider gravity = ((116.716*SG-569.851)*SG+1048.046)*SG-594.914 = 12.9 degrees Plato.

4. Initial cider extract = (degrees Plato/100)*mass = (12.9/100)*43.8 = 5.6 lbs.

5. Honey extract = (82.1/100)*4.8 = 3.9 lbs.

6. Total mass = cider mass + honey mass = 43.8 + 4.8 = 48.6 lbs.

7. Total extract = cider extract + honey extract = 5.6 + 3.9 = 9.6 lbs (5.64 + 3.94 = 9.58, which gets rounded up).

8. Original gravity = 100*extract/mass = 100*9.6/48.6 = 19.7 degrees Plato.

9. Final gravity = ((116.716*SG-569.851)*SG+1048.046)*SG-594.914 = 1.0 degrees plato.

10. Alcohol by volume = 0.516*(original gravity - final gravity) = 0.516*(19.7-1.0) = 9.6%. It should be noted that calculating alcohol content is always approximate; to determine the exact value, you need to perform a distillation test on a physical sample.

Thanks for the mental workout, Shane. Updated recipe and brewlog spreadsheets can be found in the file cabinet.

## Wednesday, November 4, 2009

### I Need a Job

Since the time when Rachel's maternity leave kicked into unpaid mode (mid-July), my checkbook has lost about 42% of its value. To continue working on RePublic, I need to find a job. Otherwise, I'll need to quit and find a job. I contacted most of the breweries within an hour and a half drive of my house, but nobody's hiring right now. It's too bad that J.T. Whitney's doing its best business in the winter was an anomaly in the local brewing industry. Look for me the next time you're ordering fast food.

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