Hermit

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You could run into problems if there is something in the water that likes your beer AND you store it a long time. I was ridiculed for saying this before but it would explain why people 'suddenly' have a favorite batch they have been nursing along suddenly 'go bad' on them. A few bacteria doubling under hostile conditions might take a long time to reach a detectable threshold level but the last doubling could appear to be quite sudden.

CDGoin

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I can see that.. I'll probably boil from now on..

__________________
BEER - Some call it a problem, I call it a Hobby

1. In the primary : MarZzzzen Ale
2. In the secondary : OktOpelFest (v2.0) [Honey infused Oktoberfest]
3. In bottles : 3 Crops Honey Lemon Lager [All-Grain]

AjhW

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Nice to know, thanks

ajdelange

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OK but let's recognize that there are other things that cause beer stored for a long time to go bad:

1. Oxidation: Some of these reactions are slow. If the wort/beer is not in a reduced state when packaged and if oxygen is not excluded from the package then over time the beer may develop the (alas) familiar cardboard or other tastes.
2. Diacetyl: I keep beer for a long time because I brew large batches (and I do that so I'll have it around for a long time). Diacetyl forms after fermentation and lagering is, therefore, done over yeast so they can reabsorb it. Because I'm keeping the beer for a long time I lager in the package (kegs) and make sure there is plenty of yeast in there. Eventually the yeast die and are no longer able to remove diacetyl. Eventually (a year or more) the diacetyl starts to creep back up (the beers begin to taste caramel like). Don't really know the mechanism - is there still acetolactate in there converting to diacetyl with no viable yeast to pick it up?
3. Whatever happens to Weizen beer: This is probably the most extreme example. Weizen beer just can't be stored for more than a couple of months. I suspect the problem is oxidation by my Weizens are stored no differently that my lagers. I remember trying to explain (in my halting German) to a bunch of good Burghers who wanted to know if we had Weizen in the US. I said no because by the time it got over here it wasn't Weizen any more.

I have had infection in a keg (fortunately only one out of the 4 I typically fill) but it came up right away. The other problems (except 3) take more than a year in my experience.

In case you think that I am advising that boiling isn't necessary let me be clear that it is one of those things you can probably get away with omitting 99 times out of 100 but it isn't worth risking it.

gbx

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Sorry as this is off topic for the water primer How fast does the classic cardboard oxidation take to form? I did an off flavours class and I noticed they used the seibel kit for the oxidation but for light struck they just set the beer out in the sun for the afternoon. Is oxidation fast enough that you could simply bubble pure O2 through a beer and then serve it a few minutes (or hours) later as an example of the oxidation off-flavour?

Last year I had 2 batches that seemed to increase in diacetyl and a batch that started to develop acetaldhyde after a couple months in the keg stored at 17-18C. I assumed I had some sort of baterial infection and have since replaced all my plastic and striped down my kegs and boiled all the rubber parts. I'm hoping its something as straight forward as an infection.

NanoMan

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I can add the post ferment data now:

Brown Ale: pH 4.54 FG 1.016 Notes: Despite the high FG, the beer tasted remarkably dry, with the dark malts being very well expressed. All of the grain was home malted (not by me). Very pleased and a second batch is now fermenting (using commerical grains). Would like to see the finish pH down slightly.

Stout: pH 4.22 FG 1.018 Beer tastes excellent. Big (as in ciomplex), but dry with a firm bittering. Roast nicely expressed. Brewing again this weekend.

Helles: pH 4.52 FG 1.012. The beer tastes good, except that I perceive a slight minerally aspect. We'll re-evaluate post clarification and carbonation. Brewed again reducing the total calcium and using acid malt to attain lower pH (but hit only 5.51 as compared to 5.34 with the first helles). Final pH is still too high.

I've noticed that inthe 7 beers I have brewed using the EZCalc spreadsheet that with one exception (first helles) the mash pH always comes in higher than predicted. I plan to increase the addition of acid malt until I hit th target. My post ferment pH is greatly improved.

As to when I add salts. Everything (gypsum, CaCl2, chalk, MgSO4) is added at the mash. Sparge water is acidified to 5.5 using 10% phosphoric per Strong's book. I am also thinking about acidifying the mash water thusly as that might also help in lowering pH.

Cheers!

NanoMan

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PS. Scrolling through earlier posts (prior to my joining the Forum) I see mention of a Water primer. What/where is that?

Cheers!

ajdelange

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Acidifying the mash water to intended mash pH effectively reduces its alkalinity to 0. The graph at http://wetnewf.org/pdfs/alkalinity-reduction-with.html (which I originally posted here) shows the percentage alkalinity reduction as a function of target pH and original pH. Just remember that every equivalent of alkalinity removed is replaced my an equivalent of the anion of the acid.

The Primer is, in fact, this very thread.

Hermit

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First post of this thread.

NanoMan

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Thanks again, AJ. FYI, the link to Alkalinity part I appears to be broken.

Cheers!

PS There is a spreadsheet referenced (see a post on 11-12-12). Can you (or anyone) advise what spreadsheet that is? Thanks!