Sunday, November 29, 2009

+1 for Liquid Tape, or What Happens When You Forget to Put the Heat Shrink On Before Soldering

I'm starting to put together some new temperature probes. The experience reminds me why I don't do work that requires fine motor skills. Also, it's fortunate that the solder connections are hidden away because I'd have to turn in my nerd card if they had to pass inspection.

The probes I have, containing Dallas Semiconductor DS18B20s, were soldered for me by my friend and Triple Mutt Brewery founder Chuck. (He's getting into the brew controller business himself - watch this space for details.) The probes work fine with my Arduino-based microcontroller and they have become an essential part of the brewday experience, but my continuing frustration with dealing with the serial I/O aspects of that board have taken me in a different direction. I was introduced to the CAI Networks WebControl board by a thread on homebrewtalk.com and it looks like it might be just the device to eliminate my communication challenges.

The challenge I discovered upon receiving the controller is that my existing probes, which are wired for for the "parasite" operating mode of the DS18B20, won't work with the WebControl's OneWire connection port. The board is set up to expect the Dallas Semiconductor devices connected to it to be wired for normal, powered operation. There's no way to correct the manner in which the existing probes are wired, since they are potted into some excellent stainless steel probe ends from stirplates.com, so I am building some new ones with the powered wiring configuration.

I soldered the first of the set yesterday, and this post's headline is a little misleading: I omitted the heat shrink on purpose. I found that I had some difficulty getting the sensor and wire all the way to the bottom of the probe end when I assembled the first set of probes, and that was partially due to the combined diameter of the heat shrink and cabling. It was a very tight fit and frankly I'm not sure I actually got the temperature sensor all the way to the end of the 8" probe, so there might be some dead space in there that slows down the temperature transfer rate from the outside to the chip. I decided this time to omit the heatshrink tubing in favor of the conformal coating insulation provided by Liquid Tape.

There are lots of brands of Liquid Tape available. I used the one I found on the electrical aisle at Lowe's. I'm not particularly worried about it being food-safe or having high heat resistance because it's going to be sealed in the probe end and won't be exposed to the environment. I'm going to use some heatsink compound to ensure a good thermal bond between the stainless and the temperature sensor, then seal around the cable exit with J-B Weld.

One tip: the applicator in my Liquid Tape can was nigh on to useless for getting a good coating of rubber on the leads of the DS18B20. To get a reasonable result, I ended up just making a puddle of Liquid Tape on a paper plate and dipping the assembly's wires into it, letting the excess drip off each time. After a few dips, a 10 minute curing rest and then a few more dips, I had a reasonably uniform thin coating on each connection.

Brewed: 091103 Por Favor - 10 Gallons

As I suspected, the second 10 gallon batch was more straightforward than the first one because I knew what to expect.

When I did the first ten gallon batch I neglected to mention that I initially missed my target mash temperature - low - by a lot. I tried to heat the mash using a heatstick and was eventually able to get it to the right temperature. It was a PITA because I was afraid to leave the heatstick alone, fearing scorching, so I had to constantly stir the thick mash.

I did a post-mortem evaluation of the whole "how hot should the strike water be" thing to back-check the calculated value from BeerSmith. Using the calculator at Brewer's Friend I was able to confirm that the number that BeerSmith proposed was supposed to be correct, even after correcting for a lower than documented grain temperature. Somehow, though, that number wasn't translating into the right mash temperature. I suspected that there was some feature of the mash tun that was sucking the heat out of the water before it could be transferred to the mash.

For this batch, I heated the strike water to 5 F higher than the recommended value and let it sit in the tun for 5 minutes to pre-heat it. Upon examination, I found that the water temperature had dropped to 160 F. Fortunately I was ready with a heatstick, and I used it to raise the water temperature in the tun back to the required value before adding the grain bill. The mash came out right on target when I measured it. A HERMS is moving up the priority list.

I noted that the sparge water requirement was a logistics issue when I wrote about the first 10 gallon batch. Knowing this, I addressed it head-on by using two smaller pots to each heat half of the 10.2 gallons of sparge water required. Just after the mash started, I stuck a heat stick in each pot. This raised the water from ambient (around 60 F) to somewhere in the 110 F range, and as the time to sparge approached, I put one pot, with heatstick, onto the propane to raise its temperature to 168 F. While I sparged with that pot's water, I moved the other pot onto the burner to raise it to sparge temperature as well. That strategy worked great, but 5 gallons of hot water is still a lot to hoist up and dump into the mash tun. An electric HLT is moving up the priority list.

Por Favor's recipe has a larger grain bill than Geordie-Boy, and I very nearly reached the top of the big mash tun with this batch. There was only about a 2 inch headspace left after the sparge water infusion. I need to keep that in mind as I plan new brews.

Luckily, Scotty was home again so I had help transferring the 14 gallons of wort to the burner. With two heatsticks and the burner I got my rolling boil and everything went well thereafter. I scooped off most of the hot break foam in an effort to reduce boilover and clarify the wort before it went into fermentation.

Cooling wort has become increasingly easy as the water and ambient temperatures go down. I think it was less than 15 minutes before I got the wort down to below 80 F, where I put it into carboys and let it sit for a couple of hours to finally hit pitching temperature. (I had to leave for a basketball game or I would have spent the extra 10 minutes to get it down to 60 F with the immersion chiller.)

The gravity for this batch came in at 1.058, which was again higher than the estimated 1.051. I am looking forward to kegging this in a couple of weeks. Speaking of which...

Kegged: 091101 Geordie-Boy

This was my first 10 gallon kegging, and I was able to interleave it with my other brewday activities. In fact, I racked a carboy during each of the sparge cycles for the Por Favor batch. The final gravity for this Geordie-Boy was 1.012, which puts it at an ABV of 4.43%. I'm liking the attenuation of the Nottingham yeast. The sample was good, let's see how the beer tastes when I carbonate one of the two kegs today.

That leads to an interesting point: I don't have room to chill both kegs, or any more kegs for that matter. The second Geordie-Boy keg will be aging at "cellar temperature" in the garage for a while. I wonder what affect that will have on the flavor. A beer cave is moving up on the priority list.

Wednesday, November 25, 2009

You've got red on you

Ah, a day off before a holiday. What better way to celebrate the harvest and the spirit of cooperation embodied in Thanksgiving than with a brew session for a beer whose name evokes the undead?

Brewed: 091102 Shaun of the Dead

As I mentioned previously, I adapted this recipe from one provided by YooperBrew on homebrewtalk.com. It purports to be a Rogue Dead Guy Ale clone. I didn't have any of the specialty Wyeast "Pacman" strain that Rogue uses so I used Safale US-05.

This was the first five gallon batch I made using the heatsticks, and I have to say they made a big difference in the overall elapsed time. I used the propane burner and one heat stick to prepare the strike water, and it reached its temperature way faster than I expected. (That was good, because I had the grain bill ready, and I was able to start the mash before I expected.) The recipe called for a mash out in addition to the sparge, and by using both heat sticks and the propane burner, I was able to have both quantities of water available at the right time with very little effort.

Other than the three separate hop additions, there was nothing remarkable about this brew session. The boil got started well and I had plenty of wort to work with. The only negative from the batch I have noticed so far is that I came in short in the gravity department. The recipe's planned OG was 1.062, but my measured gravity was 1.058.

Wednesday, November 18, 2009

For want of a washer the pint was lost


For want of a nail the shoe was lost.
For want of a shoe the horse was lost.
For want of a horse the rider was lost.
For want of a rider the battle was lost.
For want of a battle the kingdom was lost.
And all for the want of a horseshoe nail.


During last night's inspection tour (ahem) of the brewery I was surprised to find the bottom of the kegerator awash in Por Favor. I estimate about half the batch volume was there, with a steady running drip coming from the beer line connector. Not from the keg post itself, from the connector housing. Naturally this is my fault, for doing something carelessly but with good intentions.

I have gotten into the practice of disassembling the beer lines every time I change a keg, so as to keep them clean and sanitary. The cobra taps and quick disconnects can be disassembled so that their internals can be cleaned and to provide easy access to the line itself. When doing this disassembly it pays to take note of all the parts which are disassembled, lest one turn up missing later on.

Unbenownst to me, but knownst to the manufacturer and probably every other homebrewer, the parts list for a quick disconnect includes a flat rubber washer. It's black, as is the body of the liquid QD, and it's not obvious upon disassembly as it tends to remain in the QD body when the stopper and spring are removed. However, it evidently can and will come loose, and it did so in two of my beer lines. Since I didn't know it was even there, I didn't notice it was missing when I went to reassemble the line for the Por Favor tapping.

What's odd is that I didn't notice the leaking connector at all on Sunday, so my initial reassembly must have been just tight enough to resist the keg pressure for a while. However, sometime between Sunday evening and yesterday the resistance gave way to a small but persistent leak, which eventually cost me a lot of sweet beer. I managed to cannibalize a washer from an unused CO2 line QD (where it was obvious, against the gray body of that connector) but I will need to replace the set eventually. This HBT post has a suitable replacement part number for a washer available at a hardware store. Guess where I'm going today.

In the meantime I have ordered grain for a 10 gallon batch of Por Favor, which I will make and have ready some time after Thanksgiving. I don't think I can stretch this batch that long though.

Planned: F&H Shaun of the Dead

I asked Tim to place his holiday order and he requested a Rogue Dead Guy Ale. I found a promising recipe by HBT's Yooperbrew that I'm going to adapt for local conditions and brand as "Shaun of the Dead" (a movie which featured numerous rogue dead guys). I'll be brewing it this weekend after a trip to Alabrew for the GRAAAAAIINNNS.

Sunday, November 15, 2009

A November (Batch) to Remember

Okay, that's a lame title. I can't help it. They can't all be gems.

RIP: 091001 Geordie Boy

I was ambivalent about this batch. It had sort of a thick, sweet aftertaste to it which I have decided wasn't psychosomatic after all. I drank it, sure, but it wasn't my best effort.

Kegged and Tapped: 091002 Por Favor

Another Por Favor batch that really hits the spot. I am quite fond of this recipe. It has just enough hoppiness so you know it's there but it doesn't hold you up at the gas station with a pellet gun and then escape in a Prius. (No, I don't consider that to be a cheap shot.) I should really make this the next 10 gallon batch, after...

Brewed: 091101 Geordie Boy now in 10 gallon batch size!

I've read that the effort for brewing a ten gallon batch isn't significantly different from that of a five gallon batch. I found that to be generally true, except for "a few small details."

The grain bill for this batch was massive, almost 19 pounds:



My little scale can't weigh more than 8 pounds at a time, so I had to split the 12.5 pounds of two-row malt into smaller weighments. I did get a little break though because I bought the Cara-Pils Dextrine and the three caramel malt additions at Alabrew and they combined them into one sack. That saved a lot of unpacking, weighing, and repacking from inventory.

Liquid handling in a 10 gallon batch has logistical issues that you just don't think about until you try to do the first one. For example, your sparge volume is about 11 gallons, and after sparging you have 14 gallons of wort. At 8 pounds per gallon, that's 88 pounds you have to elevate over the mash tun to sparge, and 112 pounds you have to move to the burner to boil. Good thing Scotty was home this weekend and available to help, or I would never have been able to get the boil pot positioned. I'm starting to understand why there are so many examples of three-tier brewing systems on various forums.

The sparge water issue was one I didn't anticipate, and when it came time to sparge I had to make a quick adjustment in the process. I had heated the entire volume in the big pot, being the only vessel I have that would hold that volume, but I soon recognized that (a) it was too big to hoist, (b) it was too much water to add to the tun all at once, and (c) I needed that big pot to catch wort in so having it partially full of sparge water was going to be an issue. I ended up splitting the mostly-heated volume into two more manageable parts in smaller pots, then heated them individually to strike temperature before adding them.

It's also a good thing I went ahead and built two heatsticks, because there's no way my propane burner would have been able to move enough BTU to heat all the mash and sparge water and boil the wort.

I followed the general plan outlined here. I built two 1500W heatsticks and used them in separate GCFI-protected 15A circuits in the garage. Between the heatsticks and the burner I got acceptable heating performance in the mash water, sparge water and wort. I heated the mash water totally with the heatsticks, and used the combination approach with the sparge water and the wort.

I have another heatstick partially built, with a 2000W element, but it needs a 20A circuit and I don't have one handy in the garage yet. My friend Richard has advised me to just pull a 60A subpanel into the garage for this, and I think I will, but when I do I will bring 240V and switch to an all-electric brewing process. (I'll expound on that, and the heatstick construction, in another post.)

Here are a couple of pictures of the heatsticks in action. In this picture I'm using both sticks and the burner to get the wort to boiling:



Once the boil was achieved, I dropped one heatstick out and was able to maintain a good rolling boil:



Fall weather means more rapid wort cooling. I was able to get this 10 gallon batch down below 70 F in about 35 minutes with the immersion chiller. That's not quite as fast as I was managing before, but it's still acceptable. I could get slightly better performance if I could find a way to immerse the pot but I think I'll just live with this for now.

I used Nottingham yeast for this batch. It's what I wanted to use last time but Alabrew hadn't gotten their replacement shipment after the recall. I'm hoping that the attenuation for this yeast won't leave me hanging like the last batch did. I used the pitching rate calculator at Jamil Zainasheff's website and determined that 2 11g packets of dry yeast were sufficient. (Incidentally that means that I wasted one packet when I brewed the last Por Favor batch because the US-05 is in 11g packets as well. I misread the calculator's results and added two packets, but neglected to notice it called for two 5g packets. Oh well.)

I expect the next 10 gallon batch to be easier now that I have made my mistakes with this one. On the whole it really wasn't that much different from doing five gallons. Having the heatsticks in the process cut down on the overall duration of the brew session by reducing the time to heat the mash and sparge water and get the boil going, and the cleanup was about the same as always after I was done.

Sunday, November 1, 2009

Por favor - ¡hace frío!

There's a bit of nip in the fall air now and it has become easier to cool wort.

Brewed: 091001 Por Favor

I laid down another 5 gallon batch of Por Favor. This one came in at 1.060. That might be due to a number of things, but my guess is it was the extra quarter pound of Cara-Pils Dextrine I threw in because the first 2 ounces didn't look like they were crushed.