Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Messages - erockrph

Pages: 1 ... 84 85 [86] 87 88 ... 330
Yeast and Fermentation / Re: Fermentation and light
« on: January 30, 2015, 12:40:41 PM »
Duh, of course.  Thanks.
I'll bet the big ones are a real no-no for UV.
I'm surprised that LED lights are bad.  I usually check the temp strips on my clear carboys with an LED flashlight.  It's very short time, but should I worry?
White LED's are actually blue LEDs that emit a pretty tight band at about 450nm, and are coated with a substance that emits in the 600-700nm range when hit with the blue light. The two colors combine to a perceived white color to the eye. I don't think that you would have to worry much about with a typical white LED.

All Grain Brewing / Re: Martin B. is the man!
« on: January 30, 2015, 08:38:34 AM »
that's interesting Eric. I too have managed to get extremely high AA%s in big beers that I mashed in the mid 140s straight through and fermented with english yeasts. I didn't think of LD as a culprit but it could well have been. I didn't add more grain though, I just mashed in at that temp and let it ride.
You will still get amylase activity at those temps, although a lot slower than at higher mash temps. So you don't necessarily need to add more grain as long as you hold the mash rest long enough. I was specifically trying to target limit dextrinase in that beer, as well as do an alpha rest before a beta rest, so that's why I went with the 2-step mash.

General Homebrew Discussion / Re: Misses the "memo" on sanitation
« on: January 30, 2015, 08:20:17 AM »
Bad sanitization doesn't = infection, bad sanitization= greatly increased chance of infection. On any given batch if you pitch healthy yeast they have a great advantage, but eventually you will get infections with poorly sanitized equipment.
Another thing is that the infection may take a while to show up, or might not be obvious. If your bottled beer starts to become overcarbonated, then this is a telltale sign.

All Grain Brewing / Re: Martin B. is the man!
« on: January 30, 2015, 07:28:19 AM »
Very interesting discussion and much of it beyond my ken, but will mashing longer at the lower end of the temperature spectrum with a relatively low pH optimize conversion for light lagers (as conventionally thought) or is there too much else to consider in the process to make this generalization?
I don't think anything here is refuting that idea. The question regarding limit dextrinase has always been how much of a factor does it play in the mash. Conventional brewing wisdom has typically held that it degrades too rapidly at mash temps to have much of an impact. Charlie's paper proposes that limit dextrinase may actually be a bit more stable at mash temps than originally thought, and that a lower pH may increase its activity.

Limit dextrinase, for those who aren't familiar, is capable of breaking down bonds in starches that alpha- and beta-amylase cannot (it breaks alpha 1-6 bonds at branch points). The issue is that limit dextrinase cannot access these bonds until the amylase enzymes have exposed them first. Since your typical mash rest is at a higher temp than limit dextrinase's peak activity, it isn't believed to have much of an effect on fermentability. If you can somehow boost limit dextrinase's activity while the amylase enzymes are also active, then you could see a boost in fermentability.

I have accomplished this myself in a high-gravity barleywine. I did an iterated mash, where I held a high beta-amylase rest initially, then pulled my grain bag and added more grains to bring my mash temp down to the mid 140's. The idea was that the second grain addition would supply fresh limit dextrinase to break down the dextrins from the first mash. While it is only one data point, I was able to get 83% attenuation on a 1.142 wort using a flocculant English ale strain fermented at 58F. I was quite happy with my results.

General Homebrew Discussion / Re: Thermopen sale
« on: January 29, 2015, 10:44:06 PM »
I use this with great results. I got it for $3.99 shipped from a sale on Meritline years ago and it works great. It takes 6-8 seconds or so to equalize, and mine is calibrated just fine. Even at $8 it's practically disposable. I've been meaning to pick up another one or two for dedicated food and cheese thermometers, so I don't have to share my beer one.

Equipment and Software / Re: Brewing Apps?
« on: January 29, 2015, 10:37:57 PM »
Brewer's Friend is a fantastic web-based brewing suite. If you're looking for something that you can use from multiple devices, that's where I'd start. It's nice to sketch out a recipe on my work computer, pull up the ingredient list on my phone at the LHBS, calculate my mash temps on my laptop, then log my brew day on my tablet.

A quick dip (or swab) in high proof ethanol should do the trick if you're really worried.

Yeast and Fermentation / Re: Dry yeast RO water
« on: January 29, 2015, 10:26:56 PM »
The objective is to get water molecules into the dehydrated cells. I'm not sure there is a problem with using water with very low mineralization.
Without any solutes to provide an osmolarity gradient, what is to keep the yeast cells from taking up so much water that they burst? You can kill someone by administering pure water intravenously; your blood cells end up taking up water to the point of lysis. Maybe someone with more experience in yeast biology has some better data, but I can certainly see a potential issue here.

All Grain Brewing / Re: Martin B. is the man!
« on: January 29, 2015, 10:19:10 PM »
Some thoughts I had as I read through this article:

A) It's impossible to read this without hearing it narrated in Charlie's voice. Especially when he uses the phrase "dead in the water".

B) How steep is the dropoff in limit dextrinase activity beyond 65C? Obviously this research is largely targeted at light lager breweries, but it would be nice to see another data point or two above 65C.

C) There are a lot of unanswered questions for me still. I'm not jumping to the conclusion yet that any of this data will translate to a more fermentable wort, at least for the beers I typically brew.

There are two assertions here that really seem (to me) like there is a high probability of cancelling one another out to some extent. The first is that free LD is rapidly degraded at higher temps, while malt extracts seem to preserve LD activity. The second is that a considerable portion of LD is bound in the malt and inactive. When I connect the dots, I come to a possible conclusion that the reason LD activity remains over an extended time in malt is because it is bound. By liberating more free LD, you would potentially see a more rapid degradation if it is only "protected" by being bound within the malt. Unless you can liberate LD at a faster rate than it degrades, you may not really get so much bang for your buck.

It seems like malt enzyme content and possibly temperature would play a large factor here. A more highly kilned malt mashed in the 150's may not see much of a benefit in fermentability by lowering mash pH. But at very low mash temps with lightly kilned malt, there seems to be a very likely benefit of targeting a lower mash pH to maximize free Limit Dextrinase in the mash.

Ingredients / Re: lower cost bock
« on: January 29, 2015, 05:30:52 PM »
1) How much are you really going to save with these cheaper ingredients?

2) Is that difference really worth all the work to make what could be a sub par product?
+ a bazillion

All Grain Brewing / Re: Martin B. is the man!
« on: January 29, 2015, 12:12:47 PM »
"A New Approach to Limit Dextrinase and its Role in Mashing"

It's easy to miss, but the pH values discussed in the section concerning pH optimum were measured at 20 degrees Celsius.

So if i'm reading this correctly (and it was a struggle) optimal room temp PH is 5.6, favoring apparent fermentability and w/o affecting a-amylase......

"Lowering the mash pH from
5.7 to 5.4 increased the apparent fermentability, but as
the pH decreased below 5.4 a decrease in the
fermentability value was observed. Lowering the pH
from 5.7 increased the limit dextrinase activity (Fig. 4),
but did not affect the a-amylase activity and slightly
decreased the p"-amylase activity (results not shown).
When the mash pH dropped below 5.4 the increase in
limit dextrinase activity was counteracted by a marked
decrease in both a-amylase and P-amylase activities
resulting in lower apparent fermentabilities."

Limit dextrinase doesn't have a huge effect on the mash at the temps most of us use. It's peak activity is between 140-145F, and drops off rapidly at higher temps. It could have some impact during a long, low-temp mash for something like a light lager (which is probably why it appears in the literature), or if you're doing a low-temp mash for something like a big barleywine or belgian.

All Grain Brewing / Re: Martin B. is the man!
« on: January 29, 2015, 09:57:19 AM »
Agreed. I've seen reports that show lager yeasts are not as aggressive in reducing beer pH as ale yeasts. My understanding from a Wyeast presentation is that the German Ale yeast 1007 is their most acidic producer. It is reputed as a good yeast for final fermentation of Berliners and Gose.

Here's a paper that I recently read  about the effect of gravity on proton efflux rate:
I was expecting a paper on String Theory given that description  ;D

All Grain Brewing / Re: Martin B. is the man!
« on: January 28, 2015, 09:49:12 PM »
I do like to get my German Pilsners in the %.2-5.3 range so they really "pop". Dark beers up around 5.5-5.6.

I have found that S. pastorianus strains do not lower the initial pH as much as do S. cerevisiae strains.
That's an interesting nugget of info. I will definitely be filing that one away for future reference.

All Grain Brewing / Re: Martin B. is the man!
« on: January 28, 2015, 06:18:29 PM »
ok so im game. are you guys saying basically all wort (regardless of recipe/style) will have optimal conversion and therefor considered an optimal mash at rrom temp PH 5.5-5.6? so just mash everything at 5.5-5.6?

then depending on the beer style, adjust PH in the kettle based upon the style or personal preference?

Or better yet, adjust the pH of the finished product because the yeast culture has more control over then final product pH than you or I.
If I were a professional brewer, I would definitely be measuring the pH on all my finished beers and adjusting as necessary. But you can certainly ballpark it in the mash, and I prefer to do that for simplicity's sake.

General Homebrew Discussion / Re: octoberfest 2633 starter questions
« on: January 28, 2015, 01:19:44 PM »
My starters of 2633 often take 48+ hours to show signs of activity. Sometimes it doesn't even get much of a krausen, so it's hard to tell what's going on. I usually give it 5 days or so just to be sure. I've never stepped it up a second time, so I'm not sure if the second step goes more quickly.

Pages: 1 ... 84 85 [86] 87 88 ... 330