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Messages - mabrungard

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856
General Homebrew Discussion / Re: Wow, differences in base malt...
« on: October 25, 2015, 06:56:37 PM »
Then I switched to Rahr Pale Ale malt and was making the beers the same way but they were coming out maltier and slightly heavier and darker than usual so I backed off on the mash temp (like 152° to 150°) and everything was coming out pretty nicely. 

Ken, I'm hoping that you were adjusting your mashing pH. I recall that you do. Rahr is peculiar in that it tends to produce a slightly lower mash pH than typical base malts. You may have been experiencing a lower mash and wort pH with the Rahr.

Mashing a a couple of tenths higher on your pH will produce a darker beer since color compounds are extracted better at higher pH. I also find that a lower pH tends to thin my beer body a teeny bit, but I'm not sure if a tenth or two is going to be enough to produce a notable differnce.

857
Mark, you are forgetting that we are not dealing with chlorine. We are dealing with hypochlorite and subsequent chlorophenols. The taste threshold for chlorophenols in water range between 0.1 and 2 ppb (depending upon species) according to WHO. The taste threshold for chlorophenols in beer is around 10 ppb and they are plainly apparent to virtually all tasters at 30 ppb.

Assuming that dichlorophenol is the predominant species when formed in beer (I don't know that this is true), it takes two moles of hypochlorite to produce one mole of dichlorophenol and working through the molecular weights, that means that 1 ppm hypochlorite produces about 1 ppm dichlorophenol. That 400 ppb chlorine taste threshold is probably actually expressed as hypochlorite and that likely means that what was acceptable in water is WAY above the taste threshold when reacted with beer organics to create chlorophenols (400 ppb >> 30 ppb).

I'm sure many beer drinkers have experienced the following phenomena. A bar serves a beer in a glass that was washed in a chlorine-based solution. A whiff of the empty glass might have a bleach aroma to it. However, when a beer is poured into the glass, the medicinal chlorophenolic aroma is hard for some drinkers to ignore. Unfortunately, some people have little sensitivity to chlorophenols. For example, some people find some phenolic Scotches to be pleasant and drinkable, but others find them over the top...mediciney. For that reason, some beer drinkers never realize that their beers are chlorophenolic bombs, but all their friends know it.

For that reason, be sure that all bleach-related disinfecting solution is gone from your equipment before beer or wort touch them. It takes so little to screw up your beer!

(Mark, your quote from Aroxa is off. They say 300 ng/L, which is 0.3 ppb.  I'm not sure that most tasters could detect it at that low level, but certainly they should at 10 ppb)

858
I'm less concerned with iodophor solution remaining on surfaces as opposed to hypochlorite solutions (bleach). It takes only incredibly low levels of hypochlorite to taint your beer with chlorophenols. So, I strongly recommend drying bleach solutions and not worrying about iodophor solutions.

859
Ingredients / Re: flavor contribution from roasted grain added at sparge
« on: October 22, 2015, 08:13:54 PM »
If color is your primary goal, that technique is probably desirable. The flavor contributions will be reduced by the late addition. You can read more about the pluses and minuses of the technique on Bru'n Water's Facebook page.

860
Martin, remember that even in the presence of air the fermentation will still be anaerobic due to the Crabtree effect. The metabolic pathways used by the yeast in open vs. closed fermentation will probably not be dramatically different, but there may be some difference.

I've been reading a few academic papers on oxygen and how it relates to yeast sterols. I need to read a bit more and wrap my head around things but I believe that open fermentation, broadly speaking, should keep the average yeast sterol composition by weight significantly higher than a closed fermentation. What is the difference in beer flavors expressed by yeast whose dry weight basis is 1% ergosterol vs 0.2% ergosterol? I don't know.

Doesn't the Crabtree effect have something more to do with the production of alcohol due to the concentration of sugars in the media? I'm not really sure.

However, I do agree that the metabolic condition for the yeast under that yeast foam blanket should be primarily anaerobic. I just wonder if there is some sort of effect from micro-oxygenation of the overall system on the yeast? 

861
Yeast and Fermentation / Re: WY1028 and Sulphur
« on: October 22, 2015, 07:45:11 PM »
I like 1028 for my Am brown ale since it lends a minerally note to the beer. I've not noticed a sulfur note in the many times I've used it. Since you have a copper IC, you shouldn't be copper deficient. I've got to believe that this flaw will clear up pretty quickly.

862
All Grain Brewing / Re: Distilled Water, salt additions and PH
« on: October 21, 2015, 07:17:44 PM »
I use a triple beam Ohaus scale that was downsized to me from an old engineering firm I worked for. It reports down to 0.1 gram. It doesn't have high enough capacity for measuring grain additions, but its good for hop and mineral additions. I've got an electronic luggage scale that I use for measuring multi-pound grain additions. (yes, I checked its calibration before use!)

863
Is there any guidance as to which yeast variants are more likely to benefit from more aerobic conditions and which benefit from anaerobic?

I've always conducted sealed (anaerobic) fermentations, but I know that I could easily pump sterile filtered air into my fermenter headspace for the yeast variants that benefit from it.

864
All Grain Brewing / Re: Distilled Water, salt additions and PH
« on: October 21, 2015, 05:59:05 PM »
With Brunwater in my computer, I don't feel the need to use some shotgun gimmick, either.

While I predict that neither you or I have any desire to resort to a pre-packaged product like this, there are some people that just don't have the time, equipment, or interest to pursue our methods. For that reason, I don't fault this manufacturer for providing this product.

865
Using distilled vinegar (5%) and drug store hydrogen peroxide (3%), you can create a pretty safe peracetic acid solution. If I'm not mistaken, its the same mixture that is used to pickle the lead out of old brass fittings. 

I don't know why we homebrewers don't use it more often. It is highly effective. More importantly, I feel that Mark is correct that we should hit our equipment with an alternative disinfectant on occasion. Why not do something that is so easy.

866
Yeast and Fermentation / Re: Just say "no" to yeast rinsing
« on: October 20, 2015, 12:52:16 PM »
So I have begun using lactic acid to drop the pH under 5 and also since my water has 8 ppm calcium I add 1 gm/gallon of calcium chloride. 

Aren't we better off dropping the pH to something like 4? Yeast are pretty low pH tolerant, but many other organisms aren't.

Why the calcium chloride addition? Yeast do not need calcium. They need magnesium more than calcium.

867
All Grain Brewing / Re: Distilled Water, salt additions and PH
« on: October 16, 2015, 12:27:09 PM »
I bet that beer made a killer bunion soak  ;)

When it filled their shoes after a shart?

868
General Homebrew Discussion / Re: Playing around with final beer pH
« on: October 14, 2015, 12:31:56 PM »
There are some German breweries that mash at a more typical 5.4 to 5.5 pH and then drop the kettle wort pH a couple of tenths. You have to believe that there is a good reason they do that. Jim's result supports that. I've not tried that...yet.

869
Equipment and Software / Re: Cheap and Efficient Ferm Chamber
« on: October 12, 2015, 08:59:18 PM »
Remember, the system will have to have 2 ducts. One the supply cooled air and the other to return the warmed air. That is very similar to the system I use for my chamber excepting that I duct in and out of the freezer compartment of my brewery fridge. It works very well and I don't have to worry about refreshing the ice.

PS: you don't need a damper if the ducts enter and exit above the cold source. It will only thermosiphon if the ducts are under the cold source. 

870
All Grain Brewing / Re: Does Brita reduce Bicarbonates?
« on: October 12, 2015, 08:53:20 PM »
When I had a water softener, we recharged it with salt.  I'd expect the same from Brita, Sodium ions for Calcium & Magnesium.  I doubt that you'd get any change in alkalinity.

No. The ion-exchange resins in these units are typically pre-charged by strong acids or bases. That way their only resulting contribution to the water is H+ and OH- ions that create water. This is the same process that deionizing resin columns perform.

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