Interesting German Brewing PDF

[schematix]

2nd LoDO brew behind me now. Efficiency 25% lower than normal... think my barley crusher is going to the scrap heap soon. Anyways...

I made a marzen this time around. Just like last time, there was 0 mash aroma. However the wort sample this time lacked the intense sweet grain flavor like the standard helles recipe had. Is that sweet grain flavor specific to pilsner malt?

 

[TexasWine]

I brewed Sunday and had a thought about the plate chiller I use. My usual set up is to mount the exchanger in the horizontal with the connections pointing up. This makes connecting things easy. However, on Sunday a light bulb went off.

First of all, in the past I had assumed that simply pumping through my plate chiller was sufficient enough to purge the air out of it. I would do this while the water was being deoxygenated.

On Sunday I thought I'm not super familiar with the inner workings of one of these things, but if it's like the brazed aluminum exchangers I've seen at work, there are a ton of minute passages. My next thought was that if this is true, there is most likely some air trapped in there, somehow, some way. What I did next was eye opening.

While prepping to deoxygenate the water I unfastened the exchanger, and with the pump running, tilted it to one side, then the other, and front to back as well. Every direction I tilted it, I could see and hear the air bubbles being dislodged and pushed out by the flow of the water. So much for taking extreme care took avoid oxygen uptake.

So now I'm questioning the suitability of plate chillers for low dissolved oxygen brewing. For those of you who might be more familiar with their inner workings, do I simply need to orient the exchanger differently to avoid these air pockets?

 

[Kit_B]

...Is that sweet grain flavor specific to pilsner malt?

Kinda...Yes.
You can get a similar characteristic in other malts like 2-Row pale, but each malt will have its own unique lodo character.
Vienna is like fresh dough.
Munich is like bread crust or graham cracker.
Roast malts are far more intense, than before.
Something I used on Sunday gave me marshmallow/vanilla, but I haven't figured out which malt did that...Maybe it was caraMunich or a combination...Not sure, yet.

...I'm questioning the suitability of plate chillers for low dissolved oxygen brewing...

You're on the right track...Anything that lets air hide is suspect.
I use a plate chiller, but I also also purge it & recirc for about 15 minutes, while my strike water is boiling. Then, I chill & dose my water with sodium metabisulfite. I think 50mg/l has been OK, but I'm right on the edge.
My biggest problem these days is being able to keep the flavors that I start with. The freshness can disappear, quite fast.

I know that I need to use more SMB than some of the others, until I can find the $ for a stainless convoluted chiller.

 

[jdebonth]

I brewed a 40L (10gal) hoppy APA and split in 2 kegs 4 weeks ago (following all the recommendations for flushing o2 and closed transfer, etc). One of the kegs I let carb with high purity instrument grade CO2 (<2ppm o2), and to the other I added 120g of dextrose dissolved in a small amount of boiled water (to sterilise and de-gass), along with a sprinkle of S04 dry yeast. I pressurized this keg to 1 bar (to ensure a proper seal) and have been observing the pressure build-up: it stayed at 1 bar (14psi) for around 2 weeks and then started slowly climbing to the target 2 bar (29psi) over the second 2 weeks. It does like like the dextrose method needs a good 4 weeks to fully ferment out.

Last night I hooked up the keg conditioned keg to compare to the co2 carbed keg which has been on tap for 3 weeks now. I am very sensitive to oxidised hop aromas as this is what I have been struggling with, and in comparing the 2 kegs I would say the co2 carbed keg smells 25% oxidised whereas the keg conditioned keg smells 0% oxidised (I find early oxidation more obvious on the aroma than on the flavor).

The first half pint was a little cloudy but after that the clarity was not far off the co2 carbed keg that has been sitting cold for 4 weeks.

Needless to say dextrose keg conditioning (for ales) will be my new standard procedure...

What I would like to know though is more about the o2-scrubbing action of the yeast, hopefully there is existing research available that I have not been able to find.

- Does the o2 scrubbing occur and complete within a matter of hours?
- How much (how little) dextrose will result in full o2 removal?
- How to maximise o2 scrubbing? Growth factor of yeast? etc.

Reason for asking is that ideally I add only a minor amount of dextrose just to get the yeast going and scrub out the o2 then then carb up the rest of the batch with co2 as theoretically this grade of co2 will only add 2.8ppb of DO in the beer, I consider this negligible. This means I can eliminate the 4 week wait.

I plan to experiment further but some of the above info would be very useful to have.

 

[TheHairyHop]

I brewed a 40L (10gal) hoppy APA and split in 2 kegs 4 weeks ago (following all the recommendations for flushing o2 and closed transfer, etc). One of the kegs I let carb with high purity instrument grade CO2 (<2ppm o2), and to the other I added 120g of dextrose dissolved in a small amount of boiled water (to sterilise and de-gass), along with a sprinkle of S04 dry yeast. I pressurized this keg to 1 bar (to ensure a proper seal) and have been observing the pressure build-up: it stayed at 1 bar (14psi) for around 2 weeks and then started slowly climbing to the target 2 bar (29psi) over the second 2 weeks. It does like like the dextrose method needs a good 4 weeks to fully ferment out.

Last night I hooked up the keg conditioned keg to compare to the co2 carbed keg which has been on tap for 3 weeks now. I am very sensitive to oxidised hop aromas as this is what I have been struggling with, and in comparing the 2 kegs I would say the co2 carbed keg smells 25% oxidised whereas the keg conditioned keg smells 0% oxidised (I find early oxidation more obvious on the aroma than on the flavor).

The first half pint was a little cloudy but after that the clarity was not far off the co2 carbed keg that has been sitting cold for 4 weeks.

Needless to say dextrose keg conditioning (for ales) will be my new standard procedure...

What I would like to know though is more about the o2-scrubbing action of the yeast, hopefully there is existing research available that I have not been able to find.

- Does the o2 scrubbing occur and complete within a matter of hours?
- How much (how little) dextrose will result in full o2 removal?
- How to maximise o2 scrubbing? Growth factor of yeast? etc.

Reason for asking is that ideally I add only a minor amount of dextrose just to get the yeast going and scrub out the o2 then then carb up the rest of the batch with co2 as theoretically this grade of co2 will only add 2.8ppb of DO in the beer, I consider this negligible. This means I can eliminate the 4 week wait.

I plan to experiment further but some of the above info would be very useful to have.

there are posts talking about the rate of DO absorption by yeast in pure water. with beer, I would imagine it is different but on the same lines.

 

[KeyWestBrewing]

If you look at the tests done deoxygenating mash water with yeast/dextrose they show the yeast working pretty fast. Not sure what the minimum amount of sugar is for getting O2 to desired levels but 13g DME(or 7g dextrose IIRC) works for 8gal of water. Much less than you'd need to prime a keg. That's were I would start.

Why grade co2 do you have and where did you get it? From what I've been able to gather industrial grade is the purist stuff and some the others have other handling methods that could introduce impurities nobody would want in beer. Some even being carcinogens.

 

[techbrau]

I think there's more at play than just co2 purity.

Every time you attach your grey gas QD to the keg post, a pocket of air gets trapped by the o ring and forced into the keg.

The flexible plastic gas lines are also oxygen permeable. It doesn't happen fast, but they have a lot of surface area and 4+ weeks is ample opportunity for a couple milligrams worth of atmospheric oxygen to diffuse, which is all it takes to damage the beer.

I have 4 AEB kegs that I bought brand new, but I will probably be going back to bottling soon.

 

[TheHairyHop]

I want to pick up their smaller 3 or 2.5 gallon models. I've been doing 3.5 gallon batches so I can do it all indoors and ferment in a corny. smaller serving kegs would be dope

 

[jdebonth]

Why grade co2 do you have and where did you get it? From what I've been able to gather industrial grade is the purist stuff and some the others have other handling methods that could introduce impurities nobody would want in beer. Some even being carcinogens.

Here in Belgium the purer, low o2 grades of CO2 (4.5, 4.8) are easy to find and costs the same as the lower grades (3.0, 3.5, 4.0). I would be surprised if this is any different in the US as these are presumably international standards.

Could you look up where you have heard about the undocumented carcinogenic impurities? Scary stuff but this would surprise me...

Edit: Looks like it is available in the US also: http://www.praxair.com/-/media/docu...de/carbon-dioxide-co2-spec-sheet-ss-p4574.pdf

I bought grade 4.8 - Research. Cost me 30eur to fill up a big 10Kg cylinder.

 

[jdebonth]

Every time you attach your grey gas QD to the keg post, a pocket of air gets trapped by the o ring and forced into the keg.

Absolutely... I always push the valve inside the QD to flush out the gas lines and fill the little air pocket inside the QD with co2, but undoubtedly a small volume of air enters the keg with every connection. You could however unscrew the top QD valve mechanism, attach QD to keg, run co2 at a very low pressure, then then assemble the valve mechanism to the QD while co2 is flowing. Should be practically o2-free.

The flexible plastic gas lines are also oxygen permeable. It doesn't happen fast, but they have a lot of surface area and 4+ weeks is ample opportunity for a couple milligrams worth of atmospheric oxygen to diffuse, which is all it takes to damage the beer.

I wonder about this. Would this still happen given the pressure differential? Seems like any permeation would go in the reverse direction, but I do not understand the science well enough...

 

[KeyWestBrewing]

.

 

[KeyWestBrewing]

double post

 

[KeyWestBrewing]

Here in Belgium the purer, low o2 grades of CO2 (4.5, 4.8) are easy to find and costs the same as the lower grades (3.0, 3.5, 4.0). I would be surprised if this is any different in the US as these are presumably international standards.

Could you look up where you have heard about the undocumented carcinogenic impurities? Scary stuff but this would surprise me...

Edit: Looks like it is available in the US also: http://www.praxair.com/-/media/docu...de/carbon-dioxide-co2-spec-sheet-ss-p4574.pdf

I bought grade 4.8 - Research. Cost me 30eur to fill up a big 10Kg cylinder.

Google co2 impurities and lots of stuff like this comes up...

http://products.baseline-mocon.com/Asset/D032-1-BevAlert-Analytical-System.pdf

http://m.co2meter.com/?url=http://w...you-are-using-is-important&utm_referrer=#2730

The second link has a list of co2 grades with their purities.

 

[enkamania]

Currently I use Bru'n water for my water adjustments. I'm wondering, what effect does pre-boiling have on mineral content?

 

[TexasWine]

You're on the right track...Anything that lets air hide is suspect.
I use a plate chiller, but I also also purge it & recirc for about 15 minutes, while my strike water is boiling. Then, I chill & dose my water with sodium metabisulfite. I think 50mg/l has been OK, but I'm right on the edge.
My biggest problem these days is being able to keep the flavors that I start with. The freshness can disappear, quite fast.

I know that I need to use more SMB than some of the others, until I can find the $ for a stainless convoluted chiller.

Came into work this morning and did a little research. Looks like the plate chiller I use has a chevron type pattern. If I orient it in the vertical all the air pockets should be able to be flushed out. Now I just need to figure out a way to mount it.

 

[TexasWine]

I have 4 AEB kegs that I bought brand new, but I will probably be going back to bottling soon.

Lately I've had this thought more often than I'd like to admit. My reluctance to go back to bottling doesn't seem to be rooted in the desire to avoid the work. Rather, it's pride associated with rolling up the garage door and inviting neighbors to pull a swig from my keezer.

At this point my crave for the admiration of other people trumps my quest for the ultimate beer.

 

[Magnus314]

Was the natural carbed keg stored warm or cold for those 4 weeks?

Often when i do 10 gallon batches I natural carb one keg and force carb the other. They seem pretty well carbonated within about a week, and settled and clear after two weeks total. I wouldn't expect it to take 4 weeks to be fully carbed and settled.

How did you determine when to rack them to the kegs? catching those last few gravity pints has been basically a disaster for me...

 

[mabrungard]

Currently I use Bru'n water for my water adjustments. I'm wondering, what effect does pre-boiling have on mineral content?

The only effect that pre-boiling might have on water is that water with high Temporary Hardness might have a reduction in alkalinity and calcium content. This might be observed as the water getting cloudy when boiled and a white sediment (chalk) in the pot when allowed to settle. All other ion concentrations will remain unchanged.

 

[KeyWestBrewing]

The flexible plastic gas lines are also oxygen permeable. It doesn't happen fast, but they have a lot of surface area and 4+ weeks is ample opportunity for a couple milligrams worth of atmospheric oxygen to diffuse, which is all it takes to damage the beer.

I wouldn't be ready to go down that rabbit hole so easily without some testing. I know plastic is permeable but the question really is how much, if any, ingress do the lines actually allow? And, as mentioned, would it even matter given the lines are under constant pressure. According to Wambles over at CCB the best crown caps allow ~60ppb ingress per month so bottles might not be any better when it comes down to it. Without numbers though there's really no way to make a legit comparison. Not sure how you'd test that out though.

How did you determine when to rack them to the kegs? catching those last few gravity pints has been basically a disaster for me...

I think some of those guys are fermenting in kegs which makes taking gravity samples easy. They're also slowly bringing fermentation to a crawl as they lager per Narziss info IIRC. I can't speak from experience but I get the impression this makes it easier to hit the mark.

 

[Bilsch]

You could however unscrew the top QD valve mechanism, attach QD to keg, run co2 at a very low pressure, then then assemble the valve mechanism to the QD while co2 is flowing. Should be practically o2-free.

I think you might get sprayed a bit while screwing in the cap til the seal ring seats.

 

[techbrau]

I think some of those guys are fermenting in kegs which makes taking gravity samples easy. They're also slowly bringing fermentation to a crawl as they lager per Narziss info IIRC. I can't speak from experience but I get the impression this makes it easier to hit the mark.

Yep, I'm fermenting in a keg with a spunding valve acting as the airlock.

My current favorite fermentation schedule is to pitch at 43 F, let rise to 48 F over the first day or two, and hold it there until I am about 8 gravity points above my attenuation limit. At that point, I raise the pressure on the spunding valve to 10ish psi to let the beer mostly carbonate. Once I'm 4 gravity points above the attenuation limit, I start lowering the temperature back down to 43 F over the course of about 2 days. This slows down the fermentation and also encourages the majority of the yeast to drop out of suspension. Once I'm 1 or 2 gravity points above the expected FG, I do a closed rack to my purged lagering keg and fill it completely. I attach a spunding valve set at 12 psi, and give the beer another 4-5 days at 43 F before starting to lower it to 37 F by 1 degree F per day. It sits at 37 F another 2 weeks or so, by which point it's crystal clear and ready to serve.

I usually have a bit of sulfur when I rack to the lagering keg, but after the 2 weeks at 37 F it's gone.

I'm using WLP835 with a pitching rate of about 20 million cells per ml for a 1.050 beer. I aerate (after pitching) continuously for 3 hours using an aquarium pump with a 2 micron stone and inline HEPA filter.

The whole point of this schedule is to make it easy on myself so I don't have to worry about catching the beer with exactly the right amount of sugar left, and also (and perhaps more importantly) to minimize the amount of yeast I carry over into the lagering keg. I am really only looking for the yeast to scavenge any oxygen that got picked up, provide the last little bit of carbonation, and eliminate any VDKs that still might remain.

WLP835 has been by far the easiest and best lager yeast strain I've ever worked with. It does exactly what I want and handles the above schedule beautifully. Why White Labs doesn't make it a year round strain is beyond me, because it's the best lager yeast they make.

 

[jdebonth]

Was the natural carbed keg stored warm or cold for those 4 weeks?

Often when i do 10 gallon batches I natural carb one keg and force carb the other. They seem pretty well carbonated within about a week, and settled and clear after two weeks total. I wouldn't expect it to take 4 weeks to be fully carbed and settled.

How did you determine when to rack them to the kegs? catching those last few gravity pints has been basically a disaster for me...

Stored warm. It was an ale so I dry hopped, cold crashed and then added dextrose. This might explain the additional time needed.

 

[jdebonth]

I think you might get sprayed a bit while screwing in the cap til the seal ring seats.

Not with the co2-in post... yes that would happen with liquid-out but there this would not need to be done.

 

[ParanoidAndroid]

I know the topic of antioxidants in hops has been mentioned here, but has the chemical responsible for the antioxidant effect been discussed? The chemical being Xanthohumol. Hop varieties will have differing levels so one hop will have a more antioxidant effect than another. Apparently it is a very potent antioxidant.

Hopsteiner makes xanthohumol derived antioxidants. Two of which are isoxanthohumol and 8 - Prenylnaringenin (a potent phytoestrogen).

http://www.hopsteiner.com/antioxidants/

Here is an interesting paper on brewing with a xanthohumol enriched hop product. It doesn't mention the antioxidant effect though.

http://www.hopsteiner.com/wp-content/uploads/2016/03/15_brew_trials.pdf

Couple other notes:

-Vitamin E enhances the antioxidant capabilities
-It is currently being isolated and studied for numerous health benefits. We'd have to drink a few thousand beers per day to get the same effect.

 

[TheHairyHop]

Hop varieties will have differing levels so one hop will have a more antioxidant effect than another. Apparently it is a very potent antioxidant.

well now I want to know the levels in hops varieties haha

 

[ParanoidAndroid]

well now I want to know the levels in hops varieties haha

Same here. This guy had an interactive chart a few years ago, but looks like it's gone. If you scroll to a later post, one guy mentions the data on pacific jade. One of the data points is xanthohumol percentage. However, when you go to the NZ hop website, xanthohumol is no longer included in the data. I'm wondering if that chart had all the xantho numbers.

https://www.homebrewtalk.com/showthread.php?t=388669

 

[TheHairyHop]

Same here. This guy had an interactive chart a few years ago, but looks like it's gone. If you scroll to a later post, one guy mentions the data on pacific jade. One of the data points is xanthohumol percentage. However, when you go to the NZ hop website, xanthohumol is no longer included in the data. I'm wondering if that chart had all the xantho numbers.

https://www.homebrewtalk.com/showthread.php?t=388669

scott jannish was blogging about pre-fermentation hop additions seemingly not mattering in terms of aroma and flavor and someone from Trillium was posting about adding all the hops during dryhopping. I wonder if you could toss in a completely flavor irrelevant hop pre-fermentation for its antioxidant properties and then do a post-fermentation dry hop for the desired flavors

 

[ParanoidAndroid]

scott jannish was blogging about pre-fermentation hop additions seemingly not mattering in terms of aroma and flavor and someone from Trillium was posting about adding all the hops during dryhopping. I wonder if you could toss in a completely flavor irrelevant hop pre-fermentation for its antioxidant properties and then do a post-fermentation dry hop for the desired flavors

Do you have a link for that?

In looking at hops as an antioxidant, I came across Roasted Barley being one also:

"ABSTRACT

The antioxidant activity of extract from roasted barley grain was evaluated by various methods in vitro and in vivo. Results showed that the extract exhibited high antioxidant activities in vitro and in vivo, evidenced by its ability to chelate ferrous ions, scavenge hydroxyl and superoxide radicals, and prevent lipid peroxidation of liver homogenate. The extract significantly increased the total antioxidant capability (T-AOC) in aged mice (P < 0.05). The activities of antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) increased while levels of malondialodehyde (MDA) and manoamine oxidase (MAO) decreased in both the liver and brain of aged mice treated with the extract compared to the control (untreated mice). The results demonstrate potential antioxidant activities and antiaging effect of roasted barley grain. This provides scientific support for the use of roasted barley grain as an antioxidant against oxidative stress."

http://www.scirp.org/journal/PaperInformation.aspx?PaperID=35289

After doing some more reading, it looks like it can be an antioxidant or pro-oxidant. The pro-oxidant action seems to be more prevalent when transition metals are present. Brewtan-B acts as a metal chelator and prevents the Fenton Reaction. This article is long and a bit over my head. Maybe someone else can break it down better than I can.

http://onlinelibrary.wiley.com/doi/10.1111/1541-4337.12218/full

Also came across cinnamon as an antioxidant in the mash. Charlie Papazian uses a tsp in the mash. Given that there are several different things labeled as "cinnamon", I'd imagine you would want cinnamomum verum (cinnamomum zeylanicum) since its the real thing:

http://www.ncbi.nlm.nih.gov/pubmed/10077878

 

[KeyWestBrewing]

It could always be a double edged sword though. Don't some antioxidants become unstable and set off all sorts is staling reactions? I feel like I remember reading this about ascorbic acid.

 

[ParanoidAndroid]

It could always be a double edged sword though. Don't some antioxidants become unstable and set off all sorts is staling reactions? I feel like I remember reading this about ascorbic acid.

Not really sure, but I'll see if I can find more.

On the Cinnamomum zeylanicum, it acts as an antimicrobial agent too. It looks to interfere with Lactobacillus, Pediococcus, and Saccharomyces (among several others), all which are possible infections in beer. To what extent/dose, I don't know, but thought it was interesting.

https://books.google.com/books?id=vxXpBwAAQBAJ&pg=PA35&lpg=PA35&dq=Pediococcus+cinnamon&source=bl&ots=mXOKLt2zJI&sig=cC0stnMCF3wBTxiHZzORohe47pI&hl=en&sa=X&ved=0ahUKEwitwpHWmP7OAhVKRSYKHSpyAq0Q6AEILjAE#v=onepage&q=Pediococcus%20cinnamon&f=false

“At 2% concentration cinnamon is active against the food born fungi Trichoderma harzianum, Alternia alternate, Fusarium culmorum, Aspergillus versicolor, Cladosporium cladosporoides and Penicillium citrinum (Schmitz et al., 1993). At a concentration of 1%, it delays acid production by Lactobacillus plantarum and Pediococcus cerevisae (Zaika and Kissinger, 1979). It is also effective against Aspergillus niger, Bacillus cereus, Saccharomyces cerevisiae and Mycoder spp.”