Tuesday, January 10, 2012

Making a Belgian Pale Ale

Home beer making has become pretty popular lately, so much so that there are physical stores that stock supplies for it. My friends and I were interested and made some beer beer using a starter kit we bought a while back.

For this batch we decided to make a Belgian Pale Ale. While more advanced home brewers will construct their own recipes, we're still fairly new at this so we just went to the home brew store and picked up their starter kit. An important point to note about this is that we're doing "extract brewing" here as opposed to "all grain brewing", the difference being that we're using malt extract to get the sugar that the yeast needs.

Step 1: Getting Ready
If you ask any home brewer what the most important part of brewing in, they'll answer "sanitation." While the final product of this process is resistant to spoilage, they key to getting there consistently and safely is ensuring no biological baddies get to your beer before the yeast does.

As a result it is very important to thoroughly wash everything that will come in contact with the beer. We use two products called PBW (Powdered Brewery Wash) for removing organic deposits and Star San which is an odorless no-rinse sanitizer.

Step 2: Making the Wort
After everything has been cleaned, it's time to get down to the real work and make some beer. The first step, of course, is to make the concoction that the yeast eats and turns into delicious beer, the wort. This is a pretty simple process when you're doing extract brewing like we're doing here. You basically brew a tea by bringing a large batch of water to a rolling boil and adding the malt extract, hops, and other ingredients as specified by the recipe.

Step 3: Fermentation
Once you've completed your wort, it's time to make the magic happen. Here sanitation becomes a big issue again. You now have what is effectively a giant petri dish that'll grown any microorganism that is introduced. You want this to be your yeast.

The first part of this is cooling down the wort as quickly as possible. We did this in an ice bath while the wort was still in the aluminum pot to aid in heat transfer. This can be done much more quickly using a copper cooling coil with circulating water, but we didn't have one of those. Once the wort was at the temperature appropriate for the yeast we we syphoned it into the glass (not plastic) carboy where the yeast would be introduced and the fermentations would take place.

After the cooled wort had been transferred to the glass carboy we introduced the yeast. An important part of "pitching" the yeast is giving it enough air for it to start doing it's job. Knowing that we had messed this up in the past, we shook the capped carboy for a full 15 minutes, trading off when someone was getting tired. As usual, there are better tools for this (aerators like you use in a fish tank) but we didn't have one of those.

At this point, you've done all you can do, it's time to let the yeast do their magic. We let this particular batch sit about two weeks while the sugars in our wort got transformed into alcohol. Note that for better results, you'll measure the density of the wort and temperature before and after so you know how much of the sugar has been turned into alcohol. We didn't do this because we were lazy. However, we did decide to track the temperature of our wort to make sure our yeast wasn't being shocked since it had been a problem before.

In the graph you can see how much steadier and cooler the closet stayed than the hallway on the other side of the door. A closet is a good place to ferment beer.

Step 4: Bottling and Drinking
After two weeks of fermentation it was finally time to bottle the beer. Many people put their beer in a keg and then force carbonate it. This reduces the TTD (time to drunk) and gives you more consistent carbonation. However, as is the trend, we didn't have that equipment so we did it the old fashioned way. We filled and capped 48 bottles and let the yeast ferment a little more in the bottle. This provided the CO2 needed for the carbonation after another week or so. The final result was delicious and definitely worth the wait!

Here's a link to the web album with all the pictures from the process.

Technologies: Yeast, Arduino, Fire

Make Beautiful Scuba Diving Videos on the Cheap

About a year and a half ago, I learned how to scuba dive. Living within driving distance of Monterey, CA this has turned into an amazing weekend activity. The volume and diversity of wildlife means no two dives are the same. However, when many of my friends and family that don't dive, it's nice to be able to share part of that experience with them.

The GoPro HD Hero helmet camera is a great way to do that. It's cheap (relative to other underwater cameras), waterproof to 60m (200 ft) and indestructible. It also has a variety of accessories from extended batteries, to LCD preview screens that allow for flexible configurations.

When diving, how you mount your equipment can make or break a dive. If you're constantly fiddling with your gear you risk not paying attention to important things like air and depth.  If it's not attached properly, you might lose it. Both will ruin your day.

My first attempt with this camera was using GoPro's chest harness. This kept the camera securely attached and for the most part out of the way. However, my BCD inflater hose would regularly flop in front of it, blocking my shot, and it was very difficult to point it at what I wanted filmed.

After having too many fish drift just outside of the frame, I decided that I needed a better solution. I picked up a tripod mount from GoPro started putting together a monopod. While there are commercially available monopod camera extenders, none of them are very well suited for diving either because they're not very durable or they're constructed of material that corrodes easily in saltwater.

PVC pipe was an excellent choice of material for this project. It doesn't corrode in saltwater and it's easy to work with. For the connection to the camera, I found a bolt with the same threading as a standard tripod at the hardware store. I secured this to a PVC cap using epoxy and a nut. From there on, it was just PVC pipe glue with segments spaced appropriately to attach retractors. I also wrapped the largest (bottommost) segment with duct tape to provide better grip.

When put together it can be used either in third person mode (left) or camcorder mode (right). The former lets me tape some cool shots of myself and my dive buddy and the latter makes it much easier to keep the fish of interest in frame when combined with the LCD panel. Combined with the amazing video quality of the GoPro then end result is amazing. You can see clips that take advantage of both of the configurations from a dive to Point Lobos in Carmel, CA below.

Technologies: GoPro HD HERO, Adobe Premier Pro, PVC pipe