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 ...
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 ...
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 ...
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)
How much ...
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.
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 ...
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 ...
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 ...
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.
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.
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 ...
"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,...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
To add up on Denny's answer, the density of a solution of sugar and water is (quasi)linear in the range we use in homebrewing (e.g. between 1 and 1.2). (see graph below  where concentration in wt% is equivalent to degree Plato)
Using this graph, you could make a sugar solution with known density by adding sugar into water. E.g. a 5°Plato (5 wt%) solution ...
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 ...
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 ...
The first thing to note is that your refractometer and your hydrometer are measuring different physical attributes of your wort. You need to account for these differences, and additional errors.
The refractometer is primarily measuring sugar content, through the difference in refraction relative to pure water. This is where calibration comes ...
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 ...
This post from adjelange has some more substantial detail, along with a "tl;dr:" that says basically: 1.046 for 1 lb in 1 gallon, and "The density does depend on the type of sugar but is not something you would be able to detect with a hydrometer."
(I found this by doing a google search for "sucrose gravity"; it was the first result.)
Seeing how its puree >90% of it will be accessible to the yeast. Whether it all can be fermentable is a different question due to yeast health and the types of sugar (mostly fructose likely) in the fruit/puree.
As for the change in gravity its not going to be significant.
1 lb of table sugar in one gallon would be ~1.046SG
190grams is about 42% of a pound.
It's best to let it hit terminal gravity, then add priming sugar before bottling. (dry, sparkling)
Ciders can ferment very quiclky, so your drop is not a concern.
Ciders have many styles when and how you bottle depends greatly on the desired sweetness and carbonation. Ranges from dry to sweet and still to sparkling.
Sweet / Sparkling being the most ...