Scale Recipes Up/Down

BrewCalc has been updated. It now has a sheet that will scale recipes up/down according to your specifications. The first sheet ('OG, IBUs, ABV%, etc.') is a bit cleaner as well. I've hidden the ugly results of the Tinseth utilization calculations as to cut down on distraction.

I'll probably be updating BrewCalc in the next week or so with some fun new stuff. In particular, I'm working on making the Points per Gallon numbers adjustable by the user without futzing a whole lot with the calculation in J13. I'll post once I get it up and running.

Technical Tuesday Off Week

Just a quick note to say that I won't be doing the Technical Tuesday column this week. I've spent most of my research time making small improvements to the BrewCalc spreadsheet, so this portion will just have to wait until next week.

In the meantime, why don't you take some time to catch up on the older columns? You could also spend some time reading Lew Bryson's Seen Through A Glass. That's always a good time, especially if you live in or around Philadelphia.

How about a podcast? Basic Brewing, The Jamil Show, and The Sunday Session are three of my favorites.

Maybe consider becoming a beer judge, and AHA member, or checking out the Mr. Wizard column on BYO. Point is, you'll get by. See you next week!

Did I Say Three Worksheets?

Scratch that. I've now added a fourth worksheet.

It's entitled "Required Water Calculations." Not so surprisingly, it calculates the amount of water that you need for your all grain brewing based on a few parameters. In particular, those are: batch size, pounds of grain mashed, evaporation rate, boil time, and water lost to dead space.

I've also included cells that calculate approximate amounts of yield from the first runnings, as well as how much spare water you'll require to achieve the proper pre-boil volume in your kettle.

Cheers!

BrewCalc

BrewCalc Update

I updated BrewCalc once again today. It now has three distinct worksheets. I've also changed the color scheme a bit in an effort to clarify which cells are for certain types of information. Just in case it isn't as intuitive as I happen to think it is, I've included a legend as well.

Feel free to send feedback to mashematician [at] gmail [dot] com.

TBN + First Wort Gravity

Way over at The Brewing Network, a fellow forum user had asked if there was a spreadsheet that performs John Palmer's water addition for step-mashing calculations. It seemed a good enough reason to put one together, so that's what I did. If you download the spreadsheet that I make available, you'll notice that you can do the calculations in the tab labelled "Infusion Calculations." Let me know what you think if you end up using it.

Also, I stumbled upon this when searching for a way to solve a friends problem with doing AG in a 20 quart kettle on a stovetop. He was fretting about having a 20 quart brewpot and trying to do a full 5 gallon all-grain batch on his stovetop. We talked a bit about sparging, and it occurred to me that he could do a no-sparge brew if he had volume concerns. Of course, it struck me that I didn't know exactly what sort of original gravity to anticipate from first runnings, so I consulted Google. Lo and behold, I was granted the following from an old post on Probrewer.com.

As Ashton notes, Kunze* suggests that a first runnings of 20 Plato can be achieved by mashing 100 kg of malt with 3 hectoliters of water. Being from the US, these numbers don't mean a whole lot to me. Let's see what we get when we convert.

100 kg = ~220 pounds.
3 hectoliters = ~ 79.2 gallons, or ~317 quarts.

We then divide 317/220 to get ~1.44 quarts per pound. So, we now know the ratio in US units.

Ashton then goes on to provide a calculation for determining degress Plato of your first runnings from the mash thickness, assuming that Kunze is correct. It looks like this:

First wort gravity = (3 hl/100 kg malt)(20 Plato)/(3.2 hl/100 kg malt)
First wort gravity = 18.75 Plato

Of course, one can't just replace the "(3hl/100 kg malt)" with "(317g/200 lb malt)" and expect to get the same type of answer.

However, we can quickly determine a factor to make this easy. 3/100 = 0.03. 317/220 = 1.44. These two figures are separated by a factor of 48. That is 0.03*48 = 1.44 and 1.44/48 = 0.03.

Let's call (hl water/kg malt) Rm. In this case, Rm = 0.03. Let's call (quarts water/lbs malt) Ru. In this case, Ru = 1.44. 1.44/48 = 0.03. Likewise, if you wanted to determine the Rm for, say, 1.25 quarts per pound. Simply divide 1.25/48. The result is approximately 0.026. That is, it's the same ratio as 2.6 hl to 100 kg malt. Things are looking a bit simpler now.

To determine the degrees Plato of the first runnings of a mash with a water:grain ratio of 1.25 quarts per pound, we do the following.

1.) Divide 1.25 by the factor of 48. 1.25/48 = 0.026. That is 2.6 hl/100 kg malt.

2.) First Wort Gravity = (3hl/100 kg malt)(20 Plato)/(2.6 hl/100 kg malt)

3.) (0.03*20)/(0.026)

4.) (0.6)/(0.026) = ~23.1 Plato, = ~1.092 SG.

Long story short - here's an ultra-simple calculation that you can do to figure this out without exploding your brain:

.6/(X/48)

Replace X with your quarts per pound ratio (1.5, for example), and it will spit out the gravity of your first runnings in degrees Plato. Ta da!

In Excel speak, =SUM(0.6)/(B1/48)

Okay, so all the math is there, but does it work? After all Kunze notes his results are based not just on a ratio, but on a much larger amount of grain and water than the typical homebrewer can handle. If I mash ten pounds of malt at a rate of 1.44 quarts per pound, can I also expect to get a first wort of 20 Plato (~1.080 SG)? I don't know. This, to me, is the most interesting part. Experiment designs are currently being considered. I'll be sure to post about it as this side project gains more momentum.

Lastly, I want to create a better logo for the top of the page. I was thinking of putting the title of the blog into a sort of faux-calculation. For example, 'Makin'' might be translated to m4(k)/n. I haven't tried to "convert" 'them there beers' as of yet, but I'll post when I think of something. Suggestions, as always are welcome.

Happy Brewing!

*That is, Wolfgang Kunze. Author of the highly respected Technology Brewing and Malting.

Technical Tuesday: Extract Efficiency

Let's say you want to brew 5 gallons of a very basic Golden Ale. Your ingredient list looks like:

10 lbs. 2-row Pale Malt
2 ozs. Your favorite Noble Hop
Your favorite Ale Strain

You've brewed all grain once or twice before. You get the basic idea of the process, but you're not sure exactly what to expect to get OG-wise from your ten pounds of grain. You also know that variations in gravity while boiling can affect IBU utilization, and you don't want to be far off the mark. After all, this is a beer known for its subtle hopping. How can you figure out what percentage of extract you'll get from your mash?

When brewers talk about achieving a certain extract efficiency, they're talking about the amount of sugar that they coaxed out of the grain expressed as a percentage of the theoretical yield. The theoretical yield differs dependent upon the type of grain being discussed. Pale malt, Munich, Crystal, Roasted, etc. all have different theoretical yields. Luckily, there are tables that contain this information available - some are even free! [Table by Mike Uchima] We'll get back to this in a second. For right now, let's continue on with the example.

You've mashed, sparged, and collected your wort. After correcting for temperature and volume, you determine that you have a wort that will turn out to be around 1.048 in five gallons. You know that this number can be expressed in Gravity Units (GUs) as 48. Since you have five gallons, each gallon containing 48 GUs, you know that the total gravity units of your wort is 240. Since you know that the theoretical yield of two-row is 37 points per gallon, per pound of malt, you would calculate the following:

[GU*Lbs. Malt]/Gallons or, [37*10]/5 = 74. That is, if you extracted 100% of the sugars possible, your wort would have an OG of 1.074. However, it has an OG of 1.048. To determine the percentage of the sugars that you extracted, just divide Actual Extract/Potential Extract. That is, 48/74 = 64.86... ~65%. So, your system has an extract efficiency of ~65!

Of course, few recipes are this simple. Let's look at a slightly more complicated grain bill in order to calculate your efficiency.

8 lbs.2-row Pale (37 ppg)
1 lb. Munich (German) (37 ppg)
0.5 lb. Crystal 40L (37 ppg)
0.25 Chocolate 350L (30 ppg)

Since the system is known to yield around 65% efficency, we can use this to determine the resultant OG. To do this calculation by hand, you would multiply the theoretical extract by the weight of each grain used, multiply by the percentage of extract efficiency, add them all, and divide the number of gallons. It looks something like this:

T=Theoretical Extract
W=Weight of Grains
P=Percentage of Extract Efficiency
G=Total Gallons

((T1*W1*P)+(T2*W2*P)+(T3*W3*P)+(T4*W4*P))/G

For reference, you may want to download small spreadsheet that I put together to show this all in action. You can find it here. As you can see, the only big calculation here is just the calculation given above. It is the contents of cell D2. It reads:

=SUM((B2*37*C2)+(B3*37*C2)+(B4*34*C2)+(B5*30*C2))/C5

That's just the calculation above written for Excel. Armed with this knowledge, you should be able to make cells for all sorts of different fermentables, assuming that you know their theoretical yield. You can use the Uchima table linked to above, or pick up Daniels' Designing Great Beers. It is a book that is quite worthwhile, even if you already understand extract efficiency.

It is worth noting that some fermentables aren't affected by theoretical yield. Malt extracts, for example. Their efficiency is always at 100% since their fermentable sugars don't need to be extracted in any way - they're ready to go. Percentages of extract efficiency only apply to sources that you'll be extracting sugars from after all.

Go forth and be efficient!

Who's this Guy?

Joe Dougherty is a homebrewer with professional aspirations in West Philly who is quickly becoming enveloped by his hobby-turned-obsession.

Follow him as he makes some beers, drinks some beers, and occasionally makes an interesting point amongst what will probably turn out to be largely tangential pontification.

That being said, the first order of business is to share a tool that I frequently use to make calculations for the beers I brew. (Download it) This spreadsheet calculates the following:

• Original Gravity (all-grain, extract, or a combination of the two)
• Final Gravity (based on theoretical apparent attenuation rate)
• ABV%
• IBU contributions from 6 possible hop additions (using Tinseth Calculations)

As mentioned on the spreadsheet itself, the gravity calculations are averages based on figures as per Ray Daniel's Designing Great Beers (Brewers Publications, 2000). Likewise, the IBU calculations are adapted from the ever-useful Glenn Tinseth's Hop Page. I intend to add some more features (GU:BU ratio is the first to come to mind) in the future. I'll be sure to update as these features are added.

It is obviously not as detailed as a utility like BeerTools, but it will give you some quick 'n dirty numbers so that you have a vague idea of what you're doing (much like myself).