I've prepared a 1qt (~1L) yeast starter according to instructions from Wyeast.com. I didn't measure its gravity, but in theory it should be about 1.040. I am brewing a 5 gallon batch of high gravity stout @ 1.076 target original gravity. So, after pitching the starter, the total volume in the fermenter will be 5.25 gallons. How do I calculate a more accurate gravity reading from the blended starter and wort?

I am trying to figure out how Priming Sugar calculators work under the hood and just gave this illuminating article a read. Most of it makes sense, however the author talks about each different priming sugar having a different "yield rate" and I am wondering if that metric is the same as the Dry Yields I see for each ingredient on BeerSmith. For instance, Honey is listed on BeerSmith as having a Dry Yield of 75%. Does that mean, that …

I see a whole bunch of online pitch rate calculators such as this one by Brewer's Friend, but I'm struggling to find the actual formula(e) used under the hood by them. Does anybody know of any generally-accepted pitch rate formulas out there? Ideally I'd like to know what Brewer's Friend is using but I'll take anything thats in the ballpark.

The formula I've consistently found for calculating the IBU for a particular hop is: IBU = Weight (ounces) x Alpha Acid % x Utilization % x 7489 ----------------------------------------------------- Volume However I've read in several places that, for OGs north of 1.050, there is a so-called gravity correction factor that gets applied to that equation, and I am looking for clarity on it. What is this gravity correction factor, how does it impact the above equation, and why is it needed? …

I have done a few extract kit beers and now a few partial mashes. I am starting the process of ramping up to all-grain. In many online "brewing calculators", such as this mash water chemistry tool by Beersmith, they indicate that the total water volume is different than the mash water volume: I can understand that total water volume might be equal to mash volume plus sparge water volume, but is any other water (besides the sparge) added to the …

I know yeast ferments sugars into alcohol at a predictable rate, but is the same is true for carbon dioxide? Since I know the amount of sugars fermented though my gravity readings, shouldn't it be possible to calculate C02 yield? Does anyone know a formula for doing this? I ask purely out of curiosity.

I created a lemon/ginger/carrot mead and started with SG 1.120. I used a mead calculator (https://gotmead.com/blog/the-mead-calculator/) to factor in the sugars in the carrot. However, the fermentation got stuck and the SG was 1.002 — completely dry. I expected the yeast to eat the shredded carrot, but alas, yeast are not piranhas; they have no teeth. I added one pound of honey (and 1/2 tbsp. Fermax and 1 tbsp. calcium carbonate) and stirred. It is bubbling once again but how …

I'm putting together my own brewing calculations spreadsheet to develop a good understanding of the ins and outs of building a beer recipe. For my malt/mash calculations, I've chosen to use the degrees Plato scale because it makes sense to me. Can someone smarter than I please check my assumptions/calculations? They are as follows: Degrees Plato = Extract Weight (in kg) / Total Wort Weight (in kg) * 100 Where, Total Wort Weight = Total Extract Weight (in kg) + …

I am used to bottling my beer and do bottle conditioning. However, I just bought a few 5l mini kegs for the next batch which is currently fermenting. From what I have read from different sources, you need less sugar when conditioning in a mini keg than in a bottle (it varies from source to source, but it ranges from 75% to 50%, or even only 33% of the amount of sugar per liter that you would use for bottle …

I have a question regarding the conversion from Plato degrees to specific gravity, and the widely used value of 46ppg for sugar dissolved in water. According to wikipedia, plato degrees are defined by the relative amount of sugar by mass (and not volume). Consequently, 1 pound of sugar (0.453 kg) in 1 gallon (3.785 liters) gives 0.453/(3.785*0.998+0.453)=10.71% sugar in mass, taking a density of water of 0.998 kg/liter at 20°C. So this would be 10.71 Plato degree. However, formulas or …

Please tell me if I'm being overly simplistic here. I was reading the book yeast by Chris White and Jamil Zainasheff. In the book, they talk about measuring how many cells are in a slurry by using a microscope or by dilution until the slurry is clear in a test tube. However, they also mention that the size and weight (density) of a yeast cell is known, the density of water is also known. So couldn't one take a yeast …

Is there an equation that corrects specific gravity while considering temperature effect in Celsius, which does not presupposes a set hydrometer calibration temperature? A direct relation, not tables or something static. And if there is one, where would you find it? A similar question was asked Here, but the answers are all in Fahrenheit or assume a 15 C (59 f) calibration temperature.

I'm wondering if it's possible to test the mash during mash for an all grain batch to determine concentrations of calcium, magnesium, etc. Or if that is better determined by pre-mash calculations. What do commercial breweries use? Does anyone know of an off the shelf test?

If I want to convert my specific gravity reading from one temperature to an equivalent specific gravity at 60F how do I do it? Can you give me a correction factor for this case?

In making the assumption that given the final gravity and physical weight of beer (or any liquid for that matter), that you can find the total quantity, what is the calculation necessary for determining the total quantity of beer in either pounds or kilograms when the gravity of the beer is known within 2 gravity points gravity accuracy (determined by a hydrometer) and one pound weight accuracy (using a digital scale)? Also, what impact will CO2 from carbonation have on …

The simple/short version of the question: What does a hydrometer gravity reading of 1.036 really mean? Does it mean the density of the liquid is 3.6% greater than that of distilled water (ignoring inaccuracies and errors in measurement)? The context/long version of the question: When creating a yeast starter, it is commonly advised to create a light wort in the range of 1.030 to 1.040 gravity by using 100g of dry malt extract (DME) per liter of water in the …

OK, this is sort of cheating but I really liked this question so I thought I'd ask the question again in a slightly different way and try and answer it. I was wondering if we can actually estimate the expected temperature rise in the primary due to fermentation. This could be useful, for example, when trying hit your target fermentation temperature which has been identified elsewhere as one of the key variables in making good beer. edit So I'd quite …

As I understand Tinseth's formula is derived from curve fitting (as I read it from his article). However I can't see if he's using pellets or cones and I think that the utilization differs. I expect that eventually one would get the same utilization from hops and pellets so the difference in the formula should then be in the time constant in the time factor. That would lead to a formula like: IBU = ... (1-exp(-kt))/4.15 Should one use different …

I washed some yeast ( US 05 ) from my last brew; and I now have 3 jars of yeast which separated out nicely overnight. They're around 2/3 yeast, 1/3 liquid at the moment, with no trub as far as I can see. I want to use one of these next week and I'd like to know how much to use, so I went on to Mr Malty's calculator ( re-pitching from slurry tab ). There's a slider for "yeast …

I'm on day 9 of my first attempt at home brewing (1 gallon batch), and based on my measurements on day 5 and today it appears to be stuck at 1.010 Original Gravity was 1.065 Kind of just went gung-ho into it and only read later that a typical mead will have an OG of 1.092 or thereabouts and then finish at 1.010 to 1.000 or less. I expected this with its OG to go very dry with 9-10% ABV …