13

About 80% of the sugars in the malt extract are fermentable, and about 20% are not. The main fermentables are maltose, maltriose, smaller amounts of sucrose, glucose and fructose. The remainder - about 20-25% are 20% unfermentable dextrins, the remaining 5% other less common sugars with variable fermentability by ale yeasts. Thus typical values are between ...


13

You can safely dilute at any stage. Contamination is probably the biggest risk. But just takes basic sanitation practices to avoid. Oxydation: Really only an issue if 50% or more of the alcohol is present. Just don't splash, use a tube to add water below the wort surface. Diacetyl: It isn't an "infection" it's produced by all yeast during growth phase but ...


11

Mostly the high temperature. You started out at 73° C, which is already at the high side for the alfa-amylase enzymes, which convert the starches into complex sugars. While at this moment, the beta-amylase enzymes, which convert the complex sugars into simple sugars, are not yet denatured, two things work against them: The high temperature, which will ...


10

You certainly can. This is, for example, how you use a pycnometer. But, it's a bit of work. Two major problems: 1) You need to find a way to measure volume very, very precisely. The scales are reasonably accurate, but it is unlikely that you own a volumetric device accurate enough. Your SG will be screwed by an entire point for every 0.1% margin of error. ...


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 ...


8

Adding water after primary fermentation is possible and called high gravity brewing. Yeast produce more esters at higher gravity which is a disadvantage for most beer types, but often desired e.g. for Hefeweizen. For a witbier is shouldn't be a problem, either.


8

Regarding contamination, if you boil the water you are using to dilute and let it cool in a sanitised pot, then add it you should avoid bacterial or wild yeast contamination. At that OG (1080) don't worry about oxygen, if anything your yeast will need more of it due to the high starting gravity. When I do 1080+ beers, I often open the FV after 24H, to let ...


7

Here's some tips on getting an accurate hydrometer reading: check the hydrometer is calibrated, by checking that water reads 1.000 at the calibration temperature (either typically 65F or 20C). I've tried both distilled water and tap water and by both read the same. when taking a sample from a extract-based brew, particularly partial boil where top up water ...


7

The accepted knowledge on dry hopping today is as so: The majority of the hop aroma will be imparted after 24 hours. Nearly all of the hop aroma will be imparted after 72 hours. Vegetal and other off flavours will begin to develop after 2 weeks. Hop pellets are more efficient for dry hopping than whole hops*. *I spoke with Charles Faram about this and was ...


7

The problem is that the hydrometer is used the amount of sugar in the solution, not the amount of alcohol. So you can measure the original gravity (OG), and the final gravity (FG), but in kombucha the alcohol produced by the fermentation is transformed into acetic and other acids. So you can not measure if there really is alcohol in the kombucha. The only ...


6

It's not usually necessary to cool - most refractometers have built in Auto Temperature Compensation (ATC) to correct for temperatures up to 30C/86F. However, for hot samples in a warm environment then some cooling may be needed. When the ambient temp is cool (<20C/70F) the ATC will be sufficient and that the quantity of liquid is small and has a very ...


6

Your hydrometer has been calibrated to give readings at a specific temperature. Depending on the temp when you first read it and the temp after cooling a two point difference is not that surprising. If you look closely at the hydrometer, it will tell you the calibration temperature of your hydrometer. They are normally done somewhere around 60, 65 or 68F. ...


6

I've read in a few places not to do this as it risks contamination. I do it every time using a well-sanitized thief. I have never had an issue doing this. Does it increase the risk of contamination? Sure. Is it so risky as to avoid? Not to me.


6

Do not return samples to the batch. Risk of infection is very high. Sacrificing this small amount of wort makes life easier and give peace of mind. sample tubes are difficult to clean. Many are two part and need the base removed to clean properly, and sometimes take effort to reseal. samples often need to sit awhile to get to a good temp and to degas. All ...


6

"This means that the initial metabolism will be aerobic. Aerobic metabolism of sugar yields no alcohol, but still reduces the gravity." Well, actually this isn't true in virtually all fermentation situations involving Saccharomyces yeasts. S. cerevisiae is what is known as Crabtree-positive, i.e. it experiences the Crabtree effect. What this means is that,...


6

Specific gravity measures density, which is mass/volume. If you measured the total mass of your system (3000g + 300g) you would have gotten 3300 grams, but the volume is not 3000 ml because you added the DME and it increases the volume of the solution. If the volume increased by 174 ml you would get 3300/3174 = 1.040 for the density. In other words, the ...


5

An OG reading of 1.12 seems about double what you would expect for that grain bill, and gravity is only really affected by dissolved solids. Obviously the first thing you should do is check your hydrometer to make sure it is accurate, that is almost certainly the cause of the error. In water the specific gravity should read 1.00 since specific gravity is ...


5

1.020 is quite a high final gravity. It sounds like your fermentation is stuck. I would swirl the fermenter to resuspend the yeast (without introducing any air) and see if fermentation resumes. If that fails, then I would buy more of the same yeast that you originally pitched, if it's dry yeast rehydrate it in 90-100F water (32-38C) for 15 minutes, then ...


5

(TOG - GR * (BV/FV)) / (45/FV) = lbs of DME to add pre-boil to hit target OG TOG = Target Original Gravity in Points GR = Gravity Reading in Points BV = Boil Volume (This is what you are taking your reading from) FV = Final Volume (i.e. 5 gallons) 45 = # Gravity Points you get per lb of DME per gallon So lets say you are making a 5 gallon smash beer with ...


5

More bad news: If you didn't like the OG, you'll probably like the FG even less. This is because higher mash temps produce more complex (and less fermentable) sugars. You want to be making disaccharides like the maltose which will be converted to alcohol, but you probably made a lot of trisaccharides and unfermentable dextrins like maltotriose, etc. If you ...


4

You've covered the two main likely causes, with stratification being the most significant cause of error. Another potential error is in the volume measurement - if this is out, then all the calculations to relate pre and post boil gravity will be out also. Related to that is the 4 percent shrinkage that happens as wort is chilled from boiling to pitching ...


4

You've sussed out the two changes from the addition of the fruit: you'll dilute the original beer, and also change its gravity, which after more fermentation will result in a new FG. Ideally you'd measure the pre-addition specific gravity, the post-addition SG, and the post-ferment FG. The difference between the OG and the pre-add SG, plus the difference ...


4

Yes. There is the beerbug, a wifi/bluetooth SG sensor.


4

First of all, don't open the bucket if you can at all avoid it. I know this your first brew so you're excited, but in general you want to leave it alone. I don't touch my brews for 4 weeks unless dry-hopping (as in, I pitch yeast, close the bucket and don't look or think about it again for a month). Second--your beer is probably fine. The most vigorous ...


4

If it was an extract batch, it's easier to calculate the OG than to measure it. If it was all grain and you know your efficiency, we can calculate it pretty closely from the recipe.


4

Your question is very general, but I can point you in the right direction. Specific gravity (SG) is the ratio of the density of a substance to the density of a reference substance. In homebrewing we measure sugars (fermentable or not) in wort. We measure it using an hydrometer or/and a refractometer. Here are a few good articles on how to measure gravity ...


4

Yes it is still useful. You at least know where you are starting, as chthon states the second part of adding 50g to 1l of 1050 solution doesn't give 1100 solution. Here is a great table that illustrates that dissolved sugar in g/l is linear with SG. I converted it to a graph here Don't confuse this with adding 57 g of sugar to 1 l of water to get 1020 ...


4

How did you measure the gravity? Hydrometer or refractometer? What temperature did you measure at post-boil? What temperature did you measure at post-chill? The change in gravity is expected. Your gravity measurements need to be calibrated for temperature. You can use https://www.brewersfriend.com/hydrometer-temp/ to do this or have a paper copy of a ...


4

Calculate the recipe as if you were adding all the honey up front. Also take an original gravity reading with just a partial amount of honey present; if you divide the gravity points by the number of pounds of mead you used, you should know how many more points will be added later on. For instance, if you were say adding 9 pounds of honey up front, then ...


3

It's not really possible to answer this question without knowing how sweet the watermelon was. That is, we need to the watermelon's brix. When you added the watermelon, you added some water and some sugar. The sugar will ferment, increasing the alcohol content and the water will dilute, decreasing the alcohol content. According to this page, watermelons ...


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