Messages

1

Yeast and Fermentation / Re: Stepped yeast starters

« on: March 22, 2013, 04:24:17 pm »

There is more discrepancy to these yeast pitch calculators than you think. I'm talking about 2x and more.

In my experience one gram of grows about 1.4 billion cells when a stir plate is used. That is true over a fairly wide range of initial pitching rates.

Kai

2

All Grain Brewing / Re: Brun Water question

« on: March 22, 2013, 07:20:30 am »

By the way, Kai's online calculator is cool.  However, the need to plug in a code number is not.  If they made it with cookies so that the website recognized the user and brought up all their work, that would be a nice feature.  I don't like being tethered to the net, but that feature would make it more appealing.

There are two ways to solve this:
- bookmark the link with a descriptive title and manage the bookmarks. I have done that.
- sign up for BF with a trial account and you'll see a list of all your saved water calculations since having signed up. We recently added a title and description field that makes the bookkeeping easier. This is new since v1.4

I agree that keeping a code around is not very practical. I never use the code w/o the link. Sometimes folks send me just the code when it would have been as easy to send me the link+code.

The restore feature is for cases when you accidentally press the back button. This was something I asked for as a must since I hate forms where you fill stuff in, press the back-button for some stupid reason, and have to fill them out again.

I know that availability on the web is an issue. I talked to BF about this and since their business model is build around an on-line only calculator lots of investment is done with respect to redundancy and uptime. They can't afford even rare events of downtime since that can ruin their reputation. Especially if it happens while you brew. It can be argued that your records are safer on the web then on your computer unless you have a good back-up system implemented. That may not be that easy if you only work with a laptop, but there are solutions available. Many folks have lost all their recipes and other files due to hard disk crashes. That's an argument often forgotten when folks don't trust the cloud.

I'm not a big fan of the cloud either. I rather keep my stuff on my computer but in some cases it just makes life a bit easier and is not a huge risk.

Kai

3

All Grain Brewing / Re: Brun Water question

« on: March 21, 2013, 10:12:57 am »

Or just go with the Brewer's Friend water calculator and you get all that and more for free. No need to type the same thing in two places.

Kai

4

All Grain Brewing / Re: Brun Water question

« on: March 21, 2013, 08:46:49 am »

red, you are correct. Distilled water actually has a non-zero alkalinity. It’s the amount of acid needed to drop its pH from 7 to 4.3, which is a common titration end point for alkalinity measurement. Check out this calculator: http://www.brewersfriend.com/mash-chemistry-and-brewing-water-calculator/ Simply leave the default values for the source water empty and play with the pH. When you update the calculation and then look at the detailed report in the source water section (click “show report” and then click “even more detail”) to show the alkalinity  you will see how the alkalinity changes if only the pH of the water changes.

distilled water with a pH of 7, for example, has an alkalinity of 2.5 ppm as CaCO3

But erockrph is also correct that for the purpose of brewing water adjustments you can assume the alkalinity of distilled water to be 0.

If I use that calculator to determine the amount of lactic acid needed to drop the pH from 7 to 5.4 I get 0.01 ml for 4 gal of water. You can’t even measure that precisely.

Kai

5

Kegging and Bottling / Re: Carbonation (Henry's Law) question

« on: March 21, 2013, 08:00:15 am »

That is the part about Henry's Law that I'm not sure about.  Since my chest freezer is holding CO2 in, let's assume that when the beer cools back down and when it sucks gas back through the airlock that it is all CO2 coming back in.  The part I was wondering about is after the beer warms up and loses CO2, when it cools back to its original temperature does it pick up the same amount of CO2 that it lost, or is it a lower amount because the beer was originally sitting in a supersaturated state?  Since the CO2 partial pressure is the same before and after in this example, I suppose Henry's Law says that it would eventually take up the same amount of CO2.

I don’t think that your chest freezer is filled with 100% CO2. CO2 and air diffuse fairly quickly, otherwise we would not see a difference between yeast growth in an airlocked starter and one covered with foil. But there is much more CO2 in your chest freezer than there is in air.

If the headspace is 100% CO2 than a warmed up and cooled down beer will have the same CO2 level than a beer that remained at the same temp. This assumes that equilibrium was reached. How long it takes to reach that equilibrium, I don’t know. I think we are talking on the order of a few days here.

I guess another way of looking at it is, say I have two beers that have just finished fermenting.  One I leave undisturbed and the other I use a wine whip and degas as much CO2 out of it that I can.  If I let them both sit under the same amount of CO2 headspace pressure, do they eventually end up with the same amount of dissolved CO2, or does the undisturbed one hold more because it started from a supersaturated state?

A supersaturated liquid will move towards equilibrium once the production of CO2 stops. Both beers will eventually end up with the same amount of dissolved CO2

6

Kegging and Bottling / Re: Carbonation (Henry's Law) question

« on: March 20, 2013, 01:19:22 pm »

That’s a loaded question and I remember discussing this before.

I wouldn’t worry too much and base the calculations on the current temperature of the beer. If the beer has been warmed up before that and lost CO2 then it will also have reabsorbed the CO2 as it cooled down. One issue here is that as it absorbs CO2 from the headspace it would pull air into the airlock and thus lower the CO2 pressure in the head space. This will lead to less residual carbonation.

But I doubt that the effect is large enough that you have to worry about it for carbonation calculations.

There is also the issue of slow residual fermentation. How are you sure that only the added sugar will be metabolized during bottle conditioning?

Kai

7

Ingredients / Re: Lactate Taste Threshold Experiment

« on: March 11, 2013, 12:42:55 pm »

Thanks guys.

I also encourage others to try this experiment yourself. Preparing the lactate solution is fairly easy to do if you have a pH meter and pickling lime. And since you can easily correct by adding more of the un-neutralized lactic acid solution w/o changing the dilution you don't have to worry about overshooting the Ca(OH)2 additions.

Kai

8

Ingredients / Lactate Taste Threshold Experiment

« on: March 11, 2013, 08:41:41 am »

Last weekend I did a yeast handling presentation to Brew Free Or Die club members and I took the opportunity to conduct a lactate taste threshold experiment with 8 club members. While it had little to do with the topic of the technical session it is a subject where I wanted to do some experimentation for quite some time.

Acidulated malt and 88% lactic acid are very popular acids for mash pH correction but since lactic acid has a rather distinct taste the question that is on many brewer’s minds is: “How much lactic acid is too much“.

Since in most cases lactic acid is only added to counteract water alkalinity and bring the mash pH into the desirable range of 5.3-5.5 it can be assumed that the added lactic acid will not lead to a lower than normal beer pH. In other words, we don’t have to worry about beers that taste sour.  But we do have to worry about the characteristic taste of lactate. Lactate is what’s left when lactic acid gives up its proton to neutralize a base or contribute to pH changes.

The experiment was designed such that the acidity of the lactic acid was neutralized with slaked lime. While that also adds calcium in addition to the lactate it matches brewing reality where highly alkaline waters oftentimes come with high calcium levels. I had the choice between calcium (from slaked lime) or sodium (from sodium hydroxide).  Both calcium lactate and sodium lactate tasted very similar in water which shows that sodium doesn’t necessarily lead to a salty taste. I decided to go with calcium lactate since calcium is generally the dominant cation in alkaline waters.

I was very surprised to see how many of the tasters struggled with identifying the flavor in the 4 sets of samples they were given (water, Bud Light, Budweiser and Sierra Nevada Torpedo Ale). Even levels as high 1200 mg/l, which amounts to a whopping 23% acidulated malt, were not correctly identified by some tasters.  Below is a link to a more formal write-up of the experiment and those interested can go ahead and check my numbers.

Here is a chart that shows for each taster the highest lactate level that was identified as tasting like the control:


 
After having done this experiment and having tasted samples with added lactate myself I think that a safe upper limit of 400 mg/l lactate or 7% acidulated malt is reasonable with the assumption that the mash and beer pH are at acceptable levels. While 7% is higher than the 5% that is currently seen as the safe upper limit for acidulated malt use it should be noted that there might be other benefits to  reducing the amount of minerals in a given water before acidulated malt is used to neutralize the remaining alkalinity.

A formal write-up of the experiment can be found on the braukaiser.com wiki: Lactate Taste Threshold Experiment

9

Equipment and Software / Re: promash vs beersmith vs others

« on: March 07, 2013, 09:24:23 am »

I realize that I'm likely in the minority, but "online" kills it for me.  I have no internet access in the "brewery", and spotty access a lot of the time.  Ah, the joys of living away from civilization!

I hear you. I'm not a big fan of the cloud either but I do appreciate its aspect of mobility. I moved away from recipe calculators to only paper b/c I didn't want to lug a laptop to my brewing area. Now I'm moving back to these tools b/c I can simply use my phone.

You could install a stronger WIFI our use Ethernet over power line to solve the internet access issue. But keeping all the stuff on the laptop also works.

Kai

10

Equipment and Software / Re: promash vs beersmith vs others

« on: March 06, 2013, 04:19:03 pm »

An option for having encoded links for recipes is also on the works. That way you don't need to make a recipe public but are still able to share out with others.

There are a lot of neat things that can be done with an online recipe editor.

Kai

11

Equipment and Software / Re: promash vs beersmith vs others

« on: March 06, 2013, 02:39:06 pm »

i run into other brewers and it is kind of nice to pull up a picture, recipe, batch etc right away.

I use Brewer's Friend and it added a label generation option that includes a QR code to the on-line recipe (only for public recipes). Pretty neat for club meetings:

12

All Grain Brewing / Re: calcium carry over to kettle question

« on: March 06, 2013, 01:12:01 pm »

One source of Ca loss is very easily quantified. That is the Ca that reacts with malt phosphates to release H+ and lower mash pH. Kolbach found that about 28% (1/3.5) are lost that way. So when you start out with 85 ppm you’ll have about 60 ppm left after that reaction. That’s pretty close to the number’s Martin found. There might be other losses that are not as easily quantified but they appear to be less.

Kai

13

All Grain Brewing / Re: calcium carry over to kettle question

« on: March 05, 2013, 08:36:35 pm »

I wouldn't worry much about it. The calcium recommendations for water already take that into account.
Kai

Kai I don't understand this statement.
I have been using Brun Water for calculations.
I don't see where calcium carry over loss is accounted for in this, or any other water program.
Seems like I am coming up short on kettle calcium without a kettle addition.

What I mean is that when we recommend a certain Ca level in the brewing water it assumes that there will be Ca losses in the mash and boil and that the Ca level of the final beer will be lower. This is not anything the brewing calculators account for. All they care about is the mineral level in the brewing water.

That's what I mean with not worrying about it.

Kai

14

Beer Recipes / Re: Munich Dunkel Help Needed

« on: March 05, 2013, 08:31:01 pm »

A Schwarzbier has less of the deep malt character than a Dunkel and I get this by using less Munich and more Pilsner malt. The Roasted grains get you most of the color. I thought of it based on what you have available.

Kai

15

All Grain Brewing / Re: Next Step-Water

« on: March 05, 2013, 04:41:34 pm »

For your dark beers you may want to try bumping the calcium and chloride with calcium chloride. shoot for a Ca level of 100 ppm, for example. Calcium is known to suppress astringency.