10

Upvote on the question, and someone will undoubtedly come by with a better answer, but here goes off the top of my head: Acetaldehyde (a-cee-tal-de-hide....nobody says it right!) is a precursor to alcohol. It is an intermediate compound that is formed prior to the formation of EtOH/ethanol during fermentation. So the weird thing is that acetaldehyde is ...


8

You don't want to clean a copper chiller so it is shiny - if you remove the dull color (stable oxide), the metal is more likely to react and form the toxic blue-green oxide (verdigris). http://byo.com/stories/projects-and-equipment/item/1144-metallurgy-for-homebrewers Copper is relatively inert to both wort and beer. With regular use, it will build up ...


7

Q1) No chance of off flavors just from this. Q2) Yes, this is normal. The post boil gravity will always be higher than pre boil because of the water lost to evaporation. In your case about 12% of the water was boiled off, resulting in a 12% increase in gravity. Assuming a 5 gallon batch, you boiled off about 0.6 gallons.


6

As a suggestion: Heat your beer to 70 deg. Celcius (sorry, I'm metric and don't do Church-of-England units but I'm sure you can convert it to Farenheit yourself) in order to kill yeast and bacterial infection. About 10 mins at 70 deg. C should do the trick. This will also decarbonate your beer. Cool as quickly as possible, and watch out for hot side ...


5

The problem could be from temperature, alcohol tolerance and pitching rates. While the solvent character will fade with time to some degree, it can take a many months to do so and will not completely disappear. Although I can't find published figures from Fermentis, S-04 has reportedly an alcohol tolerance of 10-11% in various forums. Your 1.111 beer gives ...


5

I can think of 2 things...it might be CO2 coming from the airlock. It might also be fusel alcohols from fermenting at such high temps. In spite of what Chris White says, my own experience is that my beers come out much better fermenting at lower temps. Don't let someone else tell you what to do when your own experience says otherwise! It might also be a ...


5

No, it doesn't go away - the photochemical reaction produces compounds that do not degrade quickly and are not broken down by the yeast. Professor Beer writes: When light hits beer, it provides the energy necessary to drive a reaction that transforms the iso-alpha-acids into 3-methyl-2-butene-1-thiol. The “thiol” part of that somewhat cumbersome ...


4

It could be from bacterial contamination, old yeast, or from stale ingredients. BJCP page, Mead Faults, lists some typical causes: Vegetal Smell or taste of plants or green vegetables. Cooked, canned or rotten vegetable (cabbage, celery, onion, asparagus, parsnip) aroma and flavor: Encourage a fast, vigorous fermentation (use a healthy, active starter to ...


4

Puckering / Tea bag When the beer has a drying, puckering quality, this is typically due to increased tannins in the beer. There are two main ways tannins can enter the beer: Fly sparging with water above 5.8pH and temperature above 176°F/70°C, which extracts tannins from the grain husks Boiling a large quantity of hops for a long time. (e.g. 200g/...


4

Banana and Bubble Gum Produced intentionally in certain styles (like Hefeweizen), the flavor is reminiscent of banana candy or "Juicy Fruit" bubblegum. The flavor comes from esters produced when (1) fermenting yeast at a higher temp range than optimal, or (b) under-pitching the yeast, or otherwise stressing them out (not enough oxygen, etc).


4

Great question on a topic that I don't think is discussed much by homebrewers since we tend to stick to ales. This is a more significant issue for creating clean lagers..or at least a more obvious problem in lagers when present. Greg Noonan's New Brewing Lager Beers is about the only place I've found a solid discussion of the topic. On pp 170-171: "...


4

A cheesy smell usually means you have bacteria in your mash and they have access to oxygen. If this were a sour-mashed beer it would be considered a lost cause at this point. I don't know how this kit is supposed to work, but it's sounds like sanitation is the issue.


4

Technically, you can use baker's yeast, but I doubt you'd be as happy as you would by using brewer's yeast. Both yeasts are Saccharomyces cerevisiae, however, they are different strains of the same species that are bred to do two different jobs. Baker's yeast has been bred to produce CO2 and cause bread to rise and brewer's yeast has been bred to survive ...


4

Grats on your first brews! Sounds like yeast stress esters from possibly under pitching or lack of oxygen, maybe even autolysis if it's sitting in a primary for 3 weeks. Suggestions: Use a yeast calculator. Single pack or vials are usually only enough up to about 1.040 OG. Use a starter to grow a proper pitch or use multiple packs. Oxygenate your wort. ...


4

First, technically all beer is infected, since you pitch yeast. To be pedantic, what you're talking about is contamination. And yes, I'd say pretty much all homebrew (and even commercial beer) is contaminated to some extent. The type and severity of the contamination can vary, however.


4

Hops stored in a sealed packet in a fridge should be alright to use - even if the rest of the fridge is "crawling" with bugs. I say this because the hops grew in the open air and since picking have not been treated with anything "antibacterial" or "anti-fungal" (or should not have been). They are just dried and stored and sold. So the hops themselves are not ...


4

Diacetyl is used as a food flavoring and is safe to ingest, It is not safe to inhale diacetyl when heated and/or vaporized, and causes popcorn lung. https://www.fda.gov/Food/IngredientsPackagingLabeling/GRAS/SCOGS/ucm261273.htm There is no evidence in the available information on diacetyl or starter distillate that demonstrates or suggests reasonable ...


3

Here's some great info from How to Brew by John Palmer http://howtobrew.com/section4/chapter21-1.html


3

Was this an All Grain brew, or Extract? Was the flavor apparent from the start, or did it develop over time? Brewing All Grain pale-to-amber beers is pretty easy. If your water isn't slap full of chlorine/iron/etc (ie, tastes pretty good) then you can happily brew away without a care in the world. And a lot of all grain brewers make great beer .... up ...


3

I once made a porter with 4% black (patent) malt. It was nearly undrinkable due to the astringent ashy flavor. Letting it sit for a couple of months in the keg helped, but it was still overly assertive. Carafa III is similar to black patent. In fact some sources claim that one can be substituted for the other. If your grist included more than 1 or 2% Carafa ...


3

I have this exact same problem and it started showing up when I went to all grain. Some of the BSG kits I've done use a steeping grain process where the grains are pre-milled and they all turned out great. My extract brews have also been great. In every case I've used the same water source (tap water)... From the first all-grain batch to my latest they have ...


3

Some people say that it's better to include the IC in your boil (if it's copper) as the copper gives off micronutrients (namely zinc) as well as providing a nucleation point which reduces the chance of boilovers. See Pennies in the Boil


3

The yeast odour can really only come from yeast. After 10-14 days in primary, be sure to leave the carboy to cold condition until the yeast have settled out and the wort looks fairly clear. The apple/cidery flavour does sound like acetaldehyde, which can come from to short conditioning period, oxidation, or contamination by acetic acid bacteria. The cider-...


3

It's certainly possible - a starter is only fermented to completion, but not conditioned, so byproducts of fermentation, such as acetaldehyde (green apple) and acetolactate (which becomes diacetyl - butter/butterscotch) are still left in the beer. This have low taste thresholds (50ppb for diacetyl), so it doesn't take much for you to notice then. In a ...


3

This Wired article may help shed some light on wavelengths and bottle colour. http://www.wired.com/2013/03/physics-and-green-beer-bottles/ Amendment 1 Light in wavelengths of 350 nm to 520 nm (upper UV to mid-visible light) is known to cause skunky beer. Green bottles allow green light (520 nm to 550 nm) to pass through, whereas brown bottles (ranging ...


3

This sounds like it could be chlorophenols (typically perceived as plasticky / band-aids / medicinal / chemical flavors). If you're not using Chlorine-based sanitizers, this may have been caused by a wild yeast or bacterial infection. The fact that you also noted flocculation (cloudy) and carbonation issues is generally in line with the notion of an ...


3

As Pepi noted in the comments it would take a serious infection to be noticeable in 24 hours (Just think how long it takes yeast to get going and that is supplied into fermentable at a huge number of cells. First and foremost I recommend moving to an acid based no-rise sanitiser. Starsan is the common brand but other unbranded and just as good alternatives ...


3

No problem....I go longer than that in buckets regularly. However, dry hopping is one of the few times I still use a secondary. There are interactions between hops and yeast that can increase flowery esters. After experiencing that, I found that I get better dry hop character by getting the beer off the yeast before dry hopping.


3

Generally green apple (acetaldehyde) is due to fermentation not being complete. Did you cold crash? Did you verify that your beer was done fermenting? It is strange that your fermenter builds up so much pressure, even with an airlock attached. Are you filling the airlock to the top or to the line? Too much CO2 will cause the yeast to slow down, which ...


3

Doubtful It is remotely possible for yeast packs to have microbes on the outside of packaging from contamination at packing time. I don't see it contaminating unopened beers though. Most likely the beer has just aged and changed in flavor as all beers do.


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