Sunday, August 15, 2010

Hey now, you're an all star

I hate reading blog postings where the author makes excuses about the infrequency of his work and promises to do better. You know why? They sound like I wrote them. Instead of a pro forma mea culpa, today I'll follow up with the results of the most recent two kegged batches and describe a new recipe I made.

Kegged and tapped: 100701 Honey Half-Wit and 100702 Geordie-Boy

In the last post I talked about some newfound awareness on my part regarding how to hit the right mash temperature using my process and equipment. I have moved two batches through the process to consumption since then, and they are both pretty good. The Geordie-Boy is nowhere near as malty tasting as its recent forerunners have been, and the Half-Wit tastes as good as ever.

The Half-Wit was scheduled for a 154 F mash and it held that the whole time, but the OG came in several points short (1.036 measured vs. 1.041 predicted). I still don't know if this is due to the honey not being sufficiently dissolved at the time I take the sample, but the number makes the efficiency appear to be around 51%. The FG was 1.008 so the yeast at least took care of what little it could find. As I was racking this to the keg, it almost appeared that there was a layer of honey at the bottom of the carboy, but that might have been my imagination.

The Geordie-Boy is better than it has been. I had the mash adjusted down to 152 F and managed to start at 153. The OG into the boiler was 1.039, somewhat above the predicted 1.035, and the FG showed a corresponding overage of 1.044 vs the predicted 1.041. Since the resulting beer is a little hoppier than I perceive to be normal, I guess that overabundance of sugar was offset by the change to the hop schedule I had to adopt. During the brew day, I realized that I didn't have the right bittering hop and I had to make an adjustment on the fly, using Cascade instead of Target. I tried to adjust the IBU by adding more Cascade (at its 7% alpha acid rating) to take the place of the 11% AA Target. It worked out mathematically, but it might not have worked in the wort. It's not overbearingly hoppy, just more than I expected.

I ran the Geordie-Boy through the filter in an attempt to clean it up a little as well. I probably would have been better off to have used gelatin in it, because the amount of yeast residue that still showed up in the first few pints seems to indicate that the filter didn't do a whole lot of cleaning. Still, it's drinkable.

Didn't The Offspring have an album about this?

For the first batch of August, I wanted to try something new. Looking back on what I've made to date, one thing stands out: the recipes all have a fairly complicated grain bill, and none of them would pass muster under the German Reinheitsgebot beer purity law because of all the adjuncts I have used. (Fortunately the law doesn't seem to apply in Alabama outside of a few mile radius of the Mercedes plant in Vance.) With the recent process issues, I felt like I needed to get (back) to basics and see about creating a beer that was simple enough to help me troubleshoot further.

I have read in various places (including about a concept called SMaSH - Single Malt and Single Hop. The premise behind SMaSH is that if you really want to know how a particular grain or hop affects the flavor of your beer, you have to isolate them so you know what they're bringing to the recipe. Many people on HBT say that the SMaSH recipes they have made are among their best tasting beers.

For this batch I decided to build a SMaSH directly within BeerSmith. To keep it simple, I opted to use domestic 2-row for my base malt, even though many people have said it's almost too mild for this purpose and the resulting beers are very light tasting. I kind of see that as a virtue compared to what I've been making, and it might get some of the fence-sitters to try one of my beers. For the hops I chose Cascade, mostly because I had some.

When modeling the recipe I wanted to aim for a balanced beer that was neither malty nor hoppy. Not being a real beer scientist, I turned to an expert's advice to see how to do this.'s Biermuncher posts an interesting chart with each of his recipes showing the relationship between OG and IBU (the international bittering unit, a measure of hop content), annotated with sensory bands indicating the degree of maltiness or hoppiness a given OG/IBU ratio has. For an example, look at the chart in the thread for the brown ale recipe that was the original basis for Geordie-Boy. I can't tell where the chart originally came from to provide proper attribution, but I found a copy of the chart hosted at

I wanted the recipe to be balanced, neither malty nor hoppy. I didn't want it to have a real high ABV, but preferably somewhere in the 4% range. I also figured I wanted to stick with a simple hop addition schedule, so I started out by planning to add equal quantities at 60 minutes for bittering and at 15 minutes for flavoring.

My first action was to add enough 2-row to the recipe to raise the OG to the point where the ABV would be in the right area assuming 70% efficiency. I settled on 8 1/2 pounds, for a predicted OG of 1.041 and an ABV of 4.16%. Next, I began adjusting the hop additions so that the resulting IBU prediction would be around 21-22, a number I selected from the chart as being in the center of the "evenly balanced" range. After several iterations I settled on 0.7 oz of Cascade at 60 minutes and 0.6 oz at 15 minutes, which leads to a predicted IBU of 20.7. I decided to use Safale US-05 yeast, as it's a pretty clean yeast and should allow the flavors of the ingredients to dominate the taste of the finished product. The most important decision was what to call this recipe, of course. I settled on Smash Mouth Volume 1, since I doubt it will be the only SMaSH I make and it will save me from having to think up clever names for Volumes 2, 3, and so forth.

Brewed: 100801 Smash Mouth Volume 1

I got the 2-row already crushed and measured out from Alabrew, and got a pleasant surprise in that it was only 99 cents a pound. With the yeast and the hops, this whole batch came in at under $15.00, making it by far the least expensive one I've made. Chalk that up as another potential plus for this idiom.

I picked 150 F as the mash temperature and almost hit it, coming in at 151 F instead, still well within the beta amylase range. The SG into the boiler was 1.038, which gave me an actual efficiency of 76% into the boiler, and with an OG of 1.043 I got 73% efficiency overall. The wort was exceptionally clear coming out of the mash tun, and it maintained its clarity through the boil (except for the hot break proteins floating around, of course). I tried to whirlpool it after it cooled and transferred it to the carboy with a siphon, and I succeeded in leaving a lot more trub than usual in the kettle.

Even with the slightly higher than planned OG, I'm "in the zone" for an evenly balanced beer. The Cascade hops smelled great when I added them. I am really interested to see how this turns out.

Sunday, August 1, 2010

Wish I could remember the awesome title I had for this post

I guess it's a sign of the times. I was getting in the car to go run (and no, the irony of that is not lost on me) and I had a great idea for the title for a blog entry for Fork and Hay. Now I can't recall what it was. I suppose I'll just have to wing it.

Today we're going to talk about basics. I've written before about a strange flavor change I have detected in my batches of late. I don't know how to classify the taste, but whatever it is it is wrong for the styles I have been making. As I was pondering the latest unusual situation that resulted in an unexpected flavor component in a batch, some pieces of information I had encountered in my seemingly endless web browsing over the last couple of years started to congeal into a possible explanation.

At first, I was all set to blame my 10-gallon batch setup for the problem, because all the faulty brews had been 10 gallon batches. I have noted issues with getting the correct mash temperature before, which has prompted me to pursue designing a RIMS system (which I will hopefully finish this fall). My initial thoughts were that I either had trouble measuring the temperature correctly in the first place, or that the mash tun was doing a poor job of holding the temperature required.

In an attempt to eliminate variables, I made the last four batches (including two I'm going to talk about later which are still fermenting) using the five gallon setup. Two of these were Honey Half-Wit recipes, and I have already chronicled the success of the one that's been kegged and consumed. The other finished batch deviated from expectations, and it was the manner of this deviation that finally helped the light bulb come on, because it told me the problem was not limited to the 10 gallon equipment.

100703 Hook Me Up finished high, a full .007 above the predicted level, and it had a sweeter, thicker taste than I expected it to have. Recalling that the Por Favor and Geordie-Boy batches that weren't successful also tasted thicker and a touch sweeter, I noted that a couple of them had higher than expected finishes as well. As I read more, I learned that what I've been characterizing as "sweet" is really "malty," which is a way of stating that there were a lot non-maltose sugars in the wort, sugars that the yeast could not convert to alcohol. The presence of unfermented sugar in the finished beer helps explain the sweet, thick taste, and it also explains the high finish gravities (because sugar that the yeast can't eat continues to affect specific gravity). What could cause this excess maltiness as a shared characteristic of batches that span yeasts, grain bills, and equipment?

Sacch-re bleu!

There are numerous sources around that describe how mashing works, including a highly informative wiki entry at and this chapter of John Palmer's outstanding book "How To Brew." The essence of the process, as far as the maltiness problem is concerned, is the relative activity of two key enzymes during "saccharification" (the period during the mash where starch converts to sugar): beta amylase and alpha amylase. Beta amylase is the most effective agent in the conversion of mash starches to maltose. Alpha amylase converts some starch to maltose, but it also produces other sugars from starch as well.

Palmer's discussion of saccharification is particularly understandable and suggests the cause of my problem: if  my worts have excess non-fermentable sugar, there is too much alpha amylase action going on and not enough beta amylase activity. The two enzymes work at different temperature ranges, with beta amylase ramping down at about 152 F and alpha amylase picking up at 154 F. The conclusion, therefore, is that if there's too much non-fermentable sugar in the wort, the mash temperature was higher than it should be, because it left the saccharification mostly in the hands of alpha amylase.

So why am I mashing too high? In every batch so far, I have hit the strike water temperatures required by BeerSmith, and I am pretty sure I can eliminate problems with the software as a factor. To investigate further, I opened up BeerSmith to see what components influence the way the equation is solved, but before I describe what I found maybe I should backtrack a little and explain exactly what BeerSmith is doing for me.

Warning: physics content

The basic problem is simple in concept: heat a quantity of water and grain to a specific temperature. If you could do it in a way as simple as it sounds, for instance adding the grain to the water and then heating the result, everything would be ready to go as soon as the whole mash volume hit the temperature target. Doing it that way, you don't have to worry about how much water you're using and how much grain is involved - as long as the mash is fluid enough to allow you to stir it, it will all get to the right temperature at the same time. Of course the problem isn't that simple. I don't have a powerful enough agitator to be able to roll over a suspension of 8-plus pounds of grain in 3 or so gallons of water so that it doesn't scorch.

It's far more practical to heat the water separately and then add the grain into it, stirring to make sure all the grain is well saturated and in suspension. However, if you've ever cooked pasta  (or grits, but of course never instant) you know what happens when you add pasta to boiling water: the boil stops. That's because adding the room-temperature solids to the hot water lowered the overall temperature of the suspension as the pasta took heat out of the water until the whole mass reached thermal equilibrium.

What we're doing in the mash tun is essentially the same thing, but with a slightly different approach. With a single-infusion mash (one where there's only one charge of strike water), we need to know what temperature the water has to be in order to source enough heat to bring the whole volume into equilibrium right at our desired mash temperature. Mathematically, it's simple - all you need to know is the volume of the water you're using, the mass of the grain you're adding, and the grain's starting temperature so you'll know how much heat it's already harboring. (You'd think you could do the same thing with pasta, but there's a catch: you can't heat water to over 212 F because the result isn't water, it's steam, and it's not helping cook your penne to al dente when it rises out of the pot.)

That's pretty basic high-school level physics and chemistry, and as I said before it seemed unlikely to me that BeerSmith could screw the calculations up. As it turns out, BeerSmith has a far more sophisticated model in place that factors in several variables, including:

  • The material used in the mash tun and its weight - because the mash tun itself is not a perfect insulator and will suck heat from the mash both initially and over time. Different materials will have different specific heat values, where specific heat is a measure of how much energy is required to raise the temperature of a gram of the material 1 C. Knowing the material gives you a reasonable ballpark on its specific heat; knowing its mass lets you then calculate how much heat it's going to need as it joins the mash in reaching thermal equilibrium.
  • The starting temperature of the mash tun.
  • The volume of water to be used in the mash (which is internally converted to mass for another specific heat calculation).
  • The weight of the grain bill to be used (but not its specific heat: BeerSmith uses a constant).
  • The starting temperature of the grain.
When you create a batch sheet in BeerSmith it automatically pulls in the grain bill weight from the recipe and the strike water volume from the recipe's mash profile. (It can actually do a lot more than that, but I only use single infusion mashing so there are no other steps.) The mash tun material and weight are defined in the equipment profile for your recipe.

The starting temperature of the mash tun and the starting temperature of the grain are given default values of 72 F by the software.

Now we're getting somewhere...I think

My problem batches were created over a fairly long span of time (from November through May), and the grain storage area in the garage varied from being in the 40's to the 70's during that time. That means that the grain and mash tun temperatures varied that much as well, and you know what? I never changed the values in the software to reflect the current conditions.

Aha! I thought. Let me adjust the grain temperature of a Geordie-Boy batch and see what effect that has on the strike water temperature BeerSmith calculates to hit the target 154 F:

  • 50 F grain: 173 F water
  • 72 F grain: 169.8 F water
These numbers seem to indicate that I should have had lower mash temperatures when the grain was colder than the calculation allowed for, because I used 169 F water instead of the 173 F that was required. Clearly that's not the case, because lower mashing would favor beta amylase activity (as long is it wasn't too low, like below 131 F) and the production of maltose instead of unfermentable sugars. When you add in the fact that I didn't adjust the mash tun temperature either, the "too cold" disparity becomes even greater, with the strike water requirement moving up to 174.1 F when the grain and tun were at 50 F.

The analysis left me puzzled for a while, and then it hit me: it was about the time of the first weird batch that I started heating the strike water directly in the mash tun with my heat sticks. I first did that all the way back in November with 091103 Por Favor, and I've continued that way ever since. You've doubtless spotted the issue by now, and it goes all the way back to the beginning of the physics lesson above. If you heat the water in the mash tun, the mash tun and water are the same temperature all the way along.

Rather than starting with a 50 F or 72 F mash tun, I was starting with a tun at the strike water temperature of 169 F. There's no doubt that having all that extra heat available influenced the mash temperature upward, which could explain the apparent preference for alpha amylase, but what was the real effect? Could it really have been enough to push the mash clear out of the beta amylase range and lead to an excess of unfermentable sugar?

Going back to BeerSmith's calculator, I started doing a little iterative solving, holding the grain temperature constant while changing the mash tun temperature until it and the calculated strike water temperature converged. What I found was startling. The strike water temperature I had been using was up to 5 F too hot, because the number I converged on was around 164 F.

To figure out the effect on the mash temperature, I did a little more iterative solving by changing the mash temperature desired and the tun temperature until the strike water and tun temperatures were both at 169 F. The calculated mash temperature under those conditions was 157.5 F - pretty dramatically above the top of the beta amylase range. No wonder those beers were too malty!

The moral of the story

If anything, this exercise has taught me the value of paying attention to details (again, but if you're a regular reader here you know I'm a slow learner). By not fully understanding what all the factors were that went into the strike water temperature calculation, I wasn't able to adjust for a process change that affected its computational basis. This translated into a probable error of up to 4 F in the mash temperature of several batches, which I now know results in an increase in the ratio of unfermentables to maltose in the wort. Unplanned non-fermentable sugars lead to higher than expected finishing gravities and a maltier taste which, if not properly balanced, might not be desirable.

In short, if you don't know what you're doing, you'll screw up. And that truly is a lesson I keep learning.

Next time (soon, I promise) we'll meet the first post-revelation batch of Geordie-Boy and check in on another batch of Honey Half-Wit.