Tap water and oxygen content

[MyQul]

Here I go again spamming the forum with my musings.

I was thinking this morning that this summer we've had an awful lot of stuck fermentation threads. Now I'm absolutely convinced that lack of aeration is by far the biggest cause of stuck fermentations. Much more so than an inadequate amount of yeast, yeast with low vitality or dry pitching/sprinking yeast. Due to lazyness whenever I use dry yeast I always sprinkle it, but because I aerate my dilution water as well as my wort extremely well I never have a problem. In fact my lag times(time from pitching to signs of fermentation) are never more than about 9-10 hours.

This got me to thinking. Afiak, water companies store there water in resovoirs which then get's supplied to house holds. During the summer months the water stored would obviously get warmer. So with the stored water being warmer, I'm presuming it wont be holding as much disolved oxygen as it does during cooler times of the year.
According to the yeast book (http://www.amazon.com/dp/0937381969/?tag=skimlinks_replacement-20) Unless you use pure oxygen and an oxygen stone HBers can only aerate there wort to a maximum of about 4ppm whereas the ideal amount is 8-10ppm.
So if a HBers is not aerating their wort to the maximum they are able to, coupled with possibly less dissolved oxygen in tap water in the summer months than in winter, is this why were seeing so many stuck fermentation threads

 

[Xeno]

I would have thought that pre-brew water oxygen levels would have no impact on fermentation due to the boil.Surely any oxygen build up would be boiled out in grain and extract brews.
Kit brews may differ.


I have always assumed stuck ferments are usually down to rubbish yeast that has not been stored properly, lack of effort in aeration, people pitching at the wrong temps and/or brewing at the wrong temps trying to speed it along.


I would also say that these new no rinse cleaners can also play their part in messing things up, how many actually mix it up in the right proportions.


Not many are gonna admit they messed up when asking for help.....


Just my opinion.

 

[MyQul]

I would have thought that pre-brew water oxygen levels would have no impact on fermentation due to the boil.Surely any oxygen build up would be boiled out in grain and extract brews.
.

Your definately right here. For AG oxygen levels in the tap water will have no impact as you've boiled it all out. I think I should have been more specific. I'm for the most part talking about kits as we have had lots of stuck brew threads in relation to kits

I have always assumed stuck ferments are usually down to rubbish yeast that has not been stored properly, lack of effort in aeration, people pitching at the wrong temps and/or brewing at the wrong temps trying to speed it along.
.

These things definately play a big part in stck ferments, I think. But what has lead me to think aeration is such a big player in stuck ferments is; over the past three or four months we've had a lot of new AG brewers, mainly in part to Clibit's 'have a go at a simple AG' thread. Now my assumption is that kit brewers fail to understand the importance of aeration because it's hardly mentioned in kit instructions, if at all.

So this lack of knowledge of the importance of aeration is carried over by these new AG brewer. I think this is bourne out by the fact we have also lots of threads by new AG brewer asking for help with stuck fermentations too. Plus I doubt it was the yeast causing it as I think they would have mostly purchased a full 11g pack of something like US-05 or S04 which usually has an in date of about a year or so. It's usually kit yeast, which often is only 6-7g and can be very old due to the kit being sat on a shelf in a wharehouse somewhere, which is a big contributing factor

I would also say that these new no rinse cleaners can also play their part in messing things up, how many actually mix it up in the right proportions.
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Possibly, esspecially if they make it too strong and it kills lots of the yeast cells . I read something by the guy that invented star san. He was saying may HBer fail to make up there sanitiser in the correct ratio but what saves them from infection is that they've cleaned there kit properly before attempting to sanitise.

As you can probably tell a lot of my little hypothesis is based on assumptions and not hard evidence but it's also based on my observations of threads from the last three months or so