DIY Stir Plate

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Stir plate in action

As I continue to expand my home microbiology lab, a stir plate seemed like a logical addition. Good laboratory grade ones are reliable, but expensive ($75 on up). Cheap kits and cheaply made stir plates are easy to find on-line, but often only have middling reviews. So, I decided to make my own.

Not being an electrical engineer, I wasn’t entirely in love with the idea of soldering wires and the like, so I elected to use one of the builds that modifies a computer cooling fan. A project posted at Homebrew Finds gave basic directions, some designs for a 3D printed magnet mount, and a list of parts easily found on Amazon. A little more searching on Thingiverse found this base for the Ehrelenmeyer flask, which I shrank slightly in the Z-axis (subtracting ~5 mm, but leaving the X and Y dimensions unchanged) before printing in order to move the magnets closer to the stir bar. I also added some silicone feet under the fan, to give a little air circulation as well as to prevent movement of the stir plate when in use.

Parts list:

All told, it cost about $40 in materials to put this together. I assembled the stir plate this weekend, and ran a test with about 1.5 L of water in my 2 L flask. The setup works pretty well, and I’ll be putting it into use for my next batch.

The finished stir plate

Lab Bench Pale Ale Kegged

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Tonight I kegged my Lab Bench Pale Ale, after 13 days in the primary fermenter. The yeast had dropped out pretty nicely, leaving a golden beer with a smooth bitterness and a crisp, slightly malty aroma. The gravity was 1.010, down from 1.047, which equals 4.8% abv and ~78% apparent attenuation.

I got around 4.75 gallons of beer. Before sealing up the keg, I added 2 oz. of Cascade hops in pellet form (7.5% alpha, 5.5% beta). In about 5 days, I’ll start carbonating (leaving the hops in place); the goal is to have this ready to go on Easter!

 

Beer Tasting: von Meyer Weizen

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My von Meyer Weizen has been in the bottles for over three weeks now, waiting for the “official” tasting at the homebrew club meeting tonight. In advance of that, I did my own evaluation. This is cautioned, of course, by the fact that I don’t normally drink a lot of weizens, so I’m not entirely up on what makes a “good” or “bad” one. At any rate, here we go!

  • Basics
    • Starting gravity = 1.047; final gravity = 1.012; abv = 4.6%. Estimated IBU = 10
  • Aroma
    • Tangy and clove-forward; not much in the way of banana.
  • Appearance
    • Deep gold, almost orange in color. The beer is fairly hazy with yeast. The head is cream colored and fine in texture; persistent but not terribly tall on the pour. Head retention is quite good.
  • Flavor
    • Clove-dominant and slightly malty, with a moderate banana flavor on the finish. There’s a touch of citrus tang, too.
  • Mouthfeel
    • Body is modest, but carbonation is excellent, with fine bubbles.
  • Would I brew this again?
    • I think so! This wasn’t the most technically challenging beer to brew, but that’s alright…the overall result is pretty tasty; nice and refreshing as the weather starts to warm up. Truth be told, I like having a recipe that is quick turnaround!
  • Overall rating
    • 7/10
I did this tasting last weekend, in advance of the formal club meeting, and was curious to see how my personal assessment would compare. Somewhat to my surprise (there are some talented brewers in my club!), I placed first out of seven entries (two of which were commercial examples, and another two were good beers but brewed in other styles). If I were to guess, commercial wheat beers are handicapped a bit by long storage. According to most things I’ve read, this is a style to be consumed quickly, and homebrew might have an edge in this regard.
My weizen wasn’t the most technically challenging brew I’ve done–not by a long shot–but I am quite pleased with the results. The only minor thing I might change would be to find some way to improve the head; maybe by a partial mash to get some extra proteins into the mix? I’d definitely use the cool fermentation profile again–the balance of clove vs. banana was perfect for my taste. In any case, it’s nice to get affirmation that all-extract brewing produces great beer!

Vitamin K Kölsch Clone Kegged

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Last night (March 14), I kegged my Vitamin K Kölsch Clone. The beer had been in the primary for 13 days, fermenting from 1.045 down to 1.009. At 4.7% abv, this is exactly on target from the original recipe. Due to another beer in the fermentation chamber, I ended up not cold-crashing this one.

The kölsch is delicious at this stage–clean and lightly fruity, which I suspect will only continue to improve as it matures. I was also impressed by how well the batch has clarified, resulting in a beautifully clear and light yellow beer. A good yeast strain (as an aside, the sulfur production for this one noted by White Labs was indeed prominent–but thankfully it dissipated by kegging time).
This beer will be very nice for the upcoming warm months. I kegged just a touch under 5 gallons of beer, and am carbonating it at 13.5 psi at 42°. This is approximately 2.5 volumes of CO2.

Live Long and Porter – Kegged

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Today, Stardate 68649.4, I kegged Live Long and Porter. This beer had been fermenting for nine days, with some nice and vigorous yeast action along the way.

Final gravity was 1.016, down from a starting gravity of 1.050. This works out as 4.5% abv. The slightly higher final gravity is probably due to the warm mash temp (155°), which I’m guessing left the wort a little less fermentable. Because this is a porter, I don’t consider the extra body a tragedy.

The final product is a beautiful chocolate brown. In addition to a full 5 gallon keg, I also got one 22-oz. bottle. I am carbonating that with 2 carbonation drops (per the dosage instructions on the package). Because there is a little bit of “sludge”, and the bottling process wasn’t terribly tidy (will have to work on that for the next batch), I’m going to consume the bottled beer as soon as it is carbonated. The keg is carbonating under my usual settings for the keezer, ~13.5 psi at 42°, or ~2.5 volumes of CO2.