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 ...


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

The one blunt but true answer: It's too late. There's no accurate way to know what the OG was.


3

It is very fast, probably due to the high temperature (the higher the faster it will ferment), the insulation jacket would keep it warmer. The type of yeast used cans also cause this, some yeast are more vigorous than others, but in the end, the main reason is the temperature. Depending on your room temperature, you might not need an insulation jacket (I ...


3

You can rack at any point, just be careful not to over expose your cider to air, to avoid oxidation. There are tips (mostly for wine, but still) for that here: Oxidation of red wine during racking and bottling Personnaly, for my ciders and my wines, I prefer to rack the first time just before the end of fermentation. The main reason is that fermentation ...


3

It is not uncommon to have SG fall that far after about 9 days. Adding extra sugar at any point, at beginning, end, or at this point in between, is a matter of preference. Be aware that the added sugar will continue to ferment to dryness and will simply increase the alcohol, unless you pasteurize or otherwise treat to kill off the yeast early. In my ...


2

Refractometers don't measure Brix accurately when alcohol is present. You're better off using a hydrometer if you really want to know when sugar is half gone, then it's just when gravity points are half of what you started with, e.g., when 1.100 becomes 1.050, approximately. That being said, their procedure isn't critical. Many people would just give it a ...


2

Kombucha contains a variety of micro-organisms, the most important ones of which are brewing yeast (Saccharomyces Cerevisae) and Acetobacter. The S. Cereviseae converts sugar into alcohol, after which the Acetobacter combines the alcohol with oxygen into acetic acid (vinegar). If both are in good shape and present in the proper quantities, and your Kombucha ...


1

Simple. The SG scale is wrong. Only use Brix. A refractometer is incapable of measuring SG. It's an approximation, and in this case especially, it's pretty far off. Instead of using that SG scale, use a conversion tool like this, which is way more accurate when done properly, both for OG and FG: https://www.brewersfriend.com/refractometer-calculator/ ...


1

I see two possibilities: The second recipe has an unrealistic final gravity and most likely isn't finished fermenting. Fruit has very simple sugars, with final gravities typically 0.992 to 0.999 regardless of yeast strain used in most cases, so unless there was a more complex sugar added, or an unfermentable sugar like lactose or maltodextrin, the second ...


1

With only two data points, the only thing you can conclude with any real confidence is that there is simply more dissolved sugar in a beverage with a higher finishing gravity. In the above example (again it's only two data points), it could be suggesting this particular yeast tops-out at around 8.8% AbV, because the second set of readings still retain quite ...


1

DMTaylor is correct: dry pitching dried yeast almost always works. However, there are situations in which the yeast may rehydrate, come out of hybernation and start the fermentation better if certain procedures are followed. Wine yeast strains are different from beer yeast strains and can be a little more temperamental. If Lallemand suggests such a procedure,...


1

Really the only thing that would account for a .010+ variance is that the first sample was concentrated with more sugars than the second. Temperature cannot account for such + to - swing with any gravity meter. A hydrometer would read less gravity at hotter temps since the hotter water is expanded and has more volume and less density, objects floating in ...


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