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10

In order to be able to calculate fermentation temperature, an exothermic process, we need to know how much heat (H) is "evolved" as yeasts convert sugars to alcohol. Digging around in the literature I found this article (1). Although its focus is bioethanol production, it does give some figures in terms of joules per mole which we can use to do the ...


9

If you know the gravity and physical weight of the beer, then you can work out the quantity (volume) like this: V = W / SG where V is the volume in liters W is the weight of the beer in kilos SG is the specific gravity, e.g. 1.040 For this to be accurate, you have to be weighing just beer - the trub and yeast should not be present. To convert to ...


9

The starting gravity and ending gravity serve many purposes, but ultimately will only tell you one thing, the percentage of alcohol. Some of the purposes it may serve are: Beer style guidelines Mouthfeel, flavor, bitterness, even aroma (FG) Yeast tolerance (SG) Efficiency of sugar extraction in all-grain brewing (pre-boil gravity) Hop efficiency How much ...


5

Beersmith currently allows for late addition of extract. And it allows you to enter the time at which you are entering it. Promash is popular, but worthless when it comes to updates. Beersmith is supposed to be coming out with an update later in the summer, just something to keep in mind if you chose to buy a copy.


5

Take a look at BrewBlogger. According to developer: BrewBlogger is a web-based alternative to software such as BeerSmith, ProMash, and others. I'm busy giving BrewBlogger a try now and I'm pretty impressed. In the commercial space, BeerSmith is quite popular as is ProMash. There are quite a few available in the open source space but the only ...


5

BeerCalculus is really nice to put your recipes together. Since it's a web app, it's platform agnostic. I don't believe it does anything like inventory management. I've used BeerSmith in the past, and it's really nice and worth the money if you need inventory management.


5

All temperatures are in expressed in degrees F. correction = 1.313454 - 0.132674*F + 0.002057793*F*F - 0.000002627634*F*F*F SG_corrected = SG + (correction * 0.001) http://www.primetab.com/formulas.html agrees with http://brewery.org/library/HydromCorr0992.html


5

If the starter fully fermented, most of the 1.040 should be gone; normal yeast attenuation is around 75%, so you should have 1L of 1.010 beer in the starter vessel. 1L of 1.010 beer into 19L of 1.076 OG wort would reduce the OG down to about 1.073. (76 points * 19L + 10 points * 1L) / 20L = 72.7 points = 1.073. Though if possible, you should try to ...


4

I can't say enough about BrewPal! iPhone app (which is great because I don't brew in front of my computer). Only $0.99! Built in mash (fly, batch, decoction, partial, or steep) and boil timers (so I can enjoy as many homebrews as I want and not forget to add the 15 min hops, irish moss, or wort chiller...). I'm a developer and was going to write my own ...


4

Unfortunately, there currently is no scale to quantify and measure the amount of hop flavor and aroma in beer. Essential hop oils in beer provide this hoppy flavor and aroma, so you might think that if the amount of essential hop oil in beer could be accurately measured, then such a scale for non-bitter hop quantity would exist. However, chemists have not ...


4

Here is a link to a NB document that outlines how to use one and two stage yeast starter. There are some lengthy equations that can easily be entered into a spreadsheet for easy calculation. It will also give you the different rates when using a stir plate.


4

I use BeerAlchemy (Mac/iPhone only), and it does pretty much anything I need, including keeping track of inventory. The iPhone version is really neat, and syncs to the Mac-version. The only thing I miss is listing batches by date, I use a spreadsheet on Google Docs for that.


4

I went to the thread and the chart is there. Are you referring to a different chart? If you make 5 gallon batches typically under 1.060 OG you mash tun only needs to be a little over 4.5 gallons in size. I got to this figure assuming 12lbs 2-row at 70% efficiency to get 6 gallons of 1.060 wort (preboil). If you then assume that you may on occasion want ...


4

There is brauhaus - a javascript library for homebrew beer calculations, both in the browser and on the server I have not used it - the homepage says features include: Support for multiple Javascript runtimes Node.js 0.6.x, 0.8.x, 0.10.x Chrome, Firefox, Internet Explorer 9+, Safari, Opera, etc Calculate estimated OG, FG, IBU, ABV, SRM color, ...


3

There is an efficiency difference - while a lot of the starch in caramel malts have been converted, there is still some remaining that can be extracted in a mash, but not in a steep. Also, the mash is typically done for longer than a steep, plus a sparge, which extracts more sugars from the grain. 30% extraction for a steep seems on the low side - but let's ...


3

I too was curious about this the other day. Turns out for five gallons/18.9 L of 1.060 wort at 75% apparent attenuation, 449.1 L/ 15.86 cubic feet/ 118.64 gal of CO2 is produced (standard temperature and pressure. This amounts to 0.88 kg/ 1.94 lb of CO2! I have a few charts for different gravities and apparent attenuations at my blog post about it. I ...


2

(Wow, I can't submit a constructive link post because I'm a newbie. bear with me, and upvote me so I can be similarly constructive in the future! :) Open-source brewing software: brew-journal: github.com/jsled/brew-journal (disclosure: my project :) docstring comments in the computational classes in app/models.py have links to references). qbrew: ...


2

"Beer Calculus" is great. http://beercalculus.hopville.com/recipe This calculator has an EXTENSIVE selection of malt/fermentation (preloaded OG/FG and color based on sugars), hops (with typical AA %), yeast strains (ale/lager, dry/liquid, and flocculation level), and boils/primary/secondary add-ins (lots of them!). Great calculator where you can select ...


2

Assuming you are using his pitching rate calculator, here is what I would suggest: Switch it from "Simple Starter" to either "Simple Starter with O2 at Start" or "Simple Starter with Intermittent Shaking." O2 at Start basically means you shake it up really well when you start the fermentation of the starter (or if you add oxygen via diffusion stone). ...


2

I have used BeerTools Pro quite successfully on Windows. They have a free web-based version on their site as well, but it limits the number of ingredients you can add and lacks the mash schedule calculator which I used quite a lot. I stopped using it so much when I moved from a Windows laptop to an Ubuntu laptop and found that BeerTools doesn't run under ...


2

Just going to throw this in a well. I agree perceived is hard to really calculate from person to person. It is simply that the more non-fermentable dextrines that are in your wort, the perceived bitterness will be lower. 80IBUs suddenly tastes like 20-30IBUs. Same goes for the other side, if the beer is dry and hoppy. 80IBUs may seem like 110IBUs. This ...


2

There is no calculation for sweetness. There are no sweetness units. Whenever I have seen this type of "grading" that you describe sweetness is just some sort of arbitrary lack of bitterness. But there is no reciprocal type calculation. Taking it a step further how do you calculate something that has the qualifier "perceived" in the title. Perceived ...


2

Yes, it's a simple calculation: ABV = (OG - FG) * 131 For example: ABV = (1.055 - 1.012) * 131 ABV = (0.043) * 131 = 5.633% So to reverse it, FG = (131 * OG - ABV) / 131 For example: FG = (131*1.055 - 5.633) / 131 FG = (138.205 - 5.633) / 131 = 1.012 I have seen 129 used as the scaling factor as well, which would drop the ABV to 5.547%, but for ...


2

One person has measured CO2 production and found that he got 25 gal. of CO2 for one gal. of 1.060 beer. Another person who has measured it has written "Looking at the ratio of alcohol and CO2 atomic weights in the fermentatin equation suggests that for every pound of alcohol you should get 1.045 lbs of CO2. The above brew (in the example he was writing ...


1

There's so called Balling formula to calculate "accurate enough" amounts of alcohol, CO2 and yeast mass produced during fermentation. This formula is used in all EU countries to calculate excise duty: 2.0665 gms extract in wort make 1 gm of alcohol, 0.9565 gm CO2 and 0.11 gm yeast mass Calculate weight of extract that has been consumed by yeast then ...


1

I am curious to know why you would need to work backwards to the volume. Having said that, and from my rudimentary mathematics: weight/(FG x 1000) = m3 So, multiplying by 1000 to give litres would cancel the 1000 divisor to leave: weight/FG = litres. Example: You have beer weighing 55kg and its FG is 1.005. 55/(1.005 x 1000) = 55/1005 = 0.054m3 or ...


1

In theory if you can accurately measure your density and weights its possible. But in most real world applications your two measures will be contaminated by protein, wort, alcohol and hop debris. That will make an accurate measurment impossible, albeit a scientifically sound assumption. Yeast also aren't always the same size they swell and shrink a bit as ...


1

If you can get a particularly clean sample that is just wort or water and naturally compacted yeast then this should work, at least if calibrated initially against a cell count. The trouble is that most slurries from previous ferments contain a fair amount of trub, which can be difficult to account for. If you have a conical, then cropping from the ...


1

Measuring the water in your boil is completely based on the vessel itself. The marked stick works great, sight-tubes are wonderful, etc. You can determine your actual pre and post boil volumes as you said, by simply going with 50% volumes. The end water in the fermenter will be the weighted average temperature of the water added. i.e. If you have 2.5 ...


1

The rise in temperature will depend on several factors. One, heat should rise more in large volumes, since much of the heat will have farther to go to dissipate (one reason commercial breweries have ways to remove heat in the fermentation tanks. Two, insulation, if used will cause heat to rise more, while the provision of a conductor such as a surrounding ...



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