Thursday, December 31, 2009

2010 – The Year We Make Contact With a PID, an SSR, a 60A Panel, and a Shop Vac

(Cue Slim Pickens: “Shoot, a fella could have a pretty good weekend in Vegas with all that stuff!”)

I'm not a real fan of reviewing the past when it's all chronicaled in that “Blog Archive” area to your left. Dig around under the ads, you'll find it. (Click a few ads while you're looking because I need some more grain.) I'll spend my time here looking forward into next year. In a way, what I'm hoping to do in 2010 will address some of the stuff I would have been reviewing, but don't let that stop you from clicking some ads...I mean, reviewing previous posts.

I'd like 2010 to be a year where I improve (a) product quality and (b) consumer popularity.

“Quality is conformance to requirements” and other lies they told you in ISO-9001 school

Let's think about the quality thing first. I know a lot of homebrewers take what they are doing very seriously and are into the whole contest and judging scene. Even among those who don't compete, there's a lot of effort put into creating beer that matches the BJCP guidelines, resulting in a perception of quality as an evaluation of how well a particular beer conforms to the specific elements of those guidelines.

I'm not that picky. What I will define as quality is more akin to consistency from batch to batch than conformance to style. For example, I brewed multiple batches of Geordie-Boy Ale in 2009 and I don't think any two of them were alike. None of them were particularly bad, but I'd like to get down to one consistent result so I can make planned improvements rather than accidental ones. It doesn't concern me one whit if the result matches the BJCP requirements for 11C Northern English Brown Ale as long as I like it, since I'm the one who drinks the vast majority of F&H's produce.

How can I improve consistency from batch to batch? This is a topic that I ought to know a little about, given my day job. In a commercial environment, my answer would be to decompose the process into its components and see where the variations are introduced, looking at things like (in no particular order):
  • Formulation consistency (e.g. bill of materials control)
  • Process repeatability (e.g. proper step execution and sequencing)
  • Raw material variability (e.g. material performance and characteristics consistency from lot to lot)
  • Equipment performance control (e.g. accurate measurement and control of process variables)
If you do click some ads...I mean, review the 2009 archives, you'll see that I didn't manage to achieve very highly in any one of those areas. You have to start somewhere on improvements, so I'm going to address these in particular:
  • Equipment performance control
    • Strike and sparge water temperature control
    • Fermentation temperature monitoring
    • Fermentation temperature control
    • Mash temperature monitoring
    • Mash temperature control
  • Process repeatability
    • Work instructions for production operations
    • Work instructions for cleaning operations
    • Racking process standardization
  • Raw material variability
    • Storage environmental control
    • Local crushing of grain at point of use
    • Large volume stocking of key ingredients
  • Formulation consistency
    • Inventory accuracy
    • Work instructions for weigh/dispense
    • Measurement accuracy for weigh/dispense
If I can see improvement in half of those things it will have been a good 2010. Of course, being a good consultant, if I knock them out before May I'm sure I can find more things to correct.

Actually, I'm already underway with all of the Work Instruction items, as I have been working on building ISA-95 production models in Proficy Workflow for Shaun of the Dead, and once I validate them I will extend them to the other recipes I have and will produce in the future. My approach here is to adapt the process steps that BeerSmith generates on its brew sheets into a set of Workflow forms and workflows. I'm also planning to create a modular weigh/dispense activity that I can reuse in every recipe, with a form that can be attached to a scale via serial connection or OPC, showing live weighment feedback. (A big challenge will be getting an appropriate scale, though. Anybody have an old Sartorius or Mettler-Toledo they'd be willing to part with for some homebrew?)

As far as the equipment performance items are concerned, I intend to address the water temperature control issues with an all-electric hot liquor tank (HLT). I'm going to pull a 60A subpanel out into the garage so I can run a 5500W heating element in the HLT, controlled by a PID temperature controller like this. The PID will switch a solid-state relay (SSR) attached to a heating element. This should allow me to set a precise temperature for strike and sparge water and hit and hold it every time.

Fermentation temperature control will depend on incremental improvements to my current system for now, maybe including the addition of a radiant heater for winter brewing. First, though, I need to start logging temperatures on a continuous basis. I need to finish the Webcontrol project, get my probes built, and get them positioned in the right places: mash tun, HLT, and carboys. (Need some carboy caps for that.)

Finally, with respect to raw materials, I think at some point this year I will buy a grain mill and start getting my grain whole instead of crushed. That will hopefully reduce crush variability from batch to batch, reducing the swings in efficiency. I also think it will help with freshness, as the crushed grain doesn't keep as long as whole kernels. I expect that to allow me to stock more grain so I have more flexibility in my production plans, reducing the length of the supply chain.

I'll address the consumer issues in the next post.

Friday, December 25, 2009

Merry Christmas, now how about that zombie?

Blog entries have been few and far between, but Christmas won't pass without some news.

Kegged: 091102 Shaun of the Dead

When last we left the hapless Shaun, he and his neighbor 091102 Por Favor Carboy #2 had just been rescued from the unheated fermentation freezer and brought inside to finish up. SeƱor Favor's brother carboy #1 had been kegged at a slightly underattenuated 1.018 and I attributed that to the low fermentation temperature, so I brought Shaun and Por into the house to finish up at 68 F or so.

I took a gravity on Shaun during the move and found him to be at 1.022, which is way higher than expected. When I finally decided to keg, after a week in the house, the gravity was still at 1.020, so I figured it was done and went ahead with the kegging. I will have to think back on this process and see what happened. I still have the second carboy of 091102 to keg so I will be able to see if being inside at this late stage has helped at all with fermenatation.

Tapped: 091103 Geordie-Boy (Keg #2)

Another good batch - I think I'm getting the hang of this one. Maybe just a little too bitter, but otherwise fine, very fine indeed.

2010 Outlook?

I don't have one yet, but I will be doing some planning (!) over the next week and I may even publish a calendar for '10 just to see if I can track to it.

Sunday, December 13, 2009

The flip side of freezer temperature control is revealed through lousy cabling. LOL WUT

The last couple of weeks have largely been consumed by mundane pursuits unrelated to Fork and Hay. I did make some technical progress in certain areas, learned a little more of the obvious, and harvested a portion of a batch. Let's start with the beer.

Kegged: 091103 Por Favor (half batch)

I want to try filtering. Now that I have some 10 gallon batches underway I feel a little less apprehensive about trying things that have an outside chance of creating loss or waste, and I think Por Favor is a good candidate for filtering. This beer has a tendency to have a yeasty overtone that I hope to drop out in the filtering process, and it would benefit from some additional clarity. With that in mind, I racked one of the two carboys from 091103 into a keg, and left the other carboy intact.

I measured the gravity at 1.018, which is somewhat higher than the expected 1.012. Admittedly, it started higher than expected as well (1.058 vs 1.051), but I still expected this recipe using to attenuate more using US-05. I have a feeling that this is temperature related, because when I went to pull the carboy out of the fermentation freezer the ambient temperature reading was 58 F.

It hit me then, in another one of those insights of mine that are stunningly obvious to everyone else, that...

There's no heater in a chest freezer

I didn't start brewing until May of this year. In Alabama, by May overnight low temperatures already exceed the optimum temperature for ale fermentation, so some type of cooling is needed. I was fortunate enough to have a chest freezer that I could appoint to this task, and it has served me well. However, it's now December and the ambient temperature in my garage overnight is down into the forties.

High fermentation is exothermic, and the fermenting carboys generate enough internal heat to keep the beer at several degrees over its immediate surroundings, provided the wort is warm enough to get the yeast started in the first place. In warmer climates like mine it's necessary to provide some cooling to keep things at the right temperature, and my freezer with its Johnson A419 external temperature controller has worked well. Once the most active fermentation ends the wort temperature reaches equilibrium with its environment. Again, if it's warmer outside the freezer than inside, the cooling circuit will make sure the carboy is held at an appropriate temperature.

It's cold outside the freezer now. As long as the wort is generating its own heat, things are fine, but as soon as that active fermentation phase ends the heat inside takes advantage of imperfections in the insulation and temperatures trend down gradually. It's a freezer, not a Thermos, after all. When I went to get the Por Favor carboy out and saw that the inside temperature was 58 F I realized that I am going to have to find a way to warm my fermenting batches for the next few months.

As The DS18B20 Turns

I probably could have made this observation much more quickly if I had ever completed my quest to instrument things in the brewery. I have made some progress toward the solution while once again confirming how useless I am as a solderer. I'm almost to the point of wanting to switch to conductive epoxy instead of continuing to frustrate myself.

At present I have two probes wired in "powered" mode for the DS18B20, with the devices in the stainless steel probe ends I got at One of these probes has about 15 feet of cable and the other one has about 6.

They have headphone plugs, and I can run them into a Y-adapter and use a single headphone jack for the connection. What I can't do is extend the connection using any of the 50' headphone extension cables I bought. This really frustrates me because I simply haven't been able to figure out why it doesn't work. I have verified the pinouts and corrected the crossovers I found in the cables so that they are straight through. The individual lines are stranded, not solid. Using my multimeter, I can see there's a small resistance in the the cable, on the order of 5-20 ohms. Could that be enough to throw off the timing of the signaling circuit that much?

I bought 100' of six conductor solid telephone wire to run a test. I measured its resistance to be 3 ohms over 100'. I created a simple breadboard to stick 2 DS18B20 sensors at the far end of that cable and wired it into the rest of the stuff I have prototyped. Lo and behold, I can read all four thermometers without issue. Lesson learned: don't expect digital circuit quality out of a $4.99 cable. I will need to rethink my connection strategy now that headphone plugs are not as attractive as they once were.

On a related subject, in order to power these new probes I need to supply them with a 5 VDC circuit. The WebControl board I'm using only sources 3.3 VDC on the connector designated for the temperature probe, but its documentation suggests that the +5V output on the adjacent connector (for a humidity sensor) will be capable of driving probes not connected directly to the board. I tried that and it simply didn't work, so I now use a 7805 voltage regulator device to split the input power and provide a separate regulated 5 VDC supply dedicated to the temperature devices.

I think the experimentation may be coming to an end. I plan to swap out the headphone plugs for RJ45 and use CAT-5 cable for the extensions. New probes will be made out of CAT-5.