Thursday, 20 July 2017

Mead - Final Product One Year Later

Way back in October 2016, I was frustrated with stuck fermentation on a batch of mead. Adding yeast nutrient/energizer, fermentation seemed to do the trick. Three months later, in January, I measured the specific gravity (0.996) and decided to rack it. Some residual haziness remained, so I let this mead sit for 7 months in the dark, in a sealed carboy, hoping that this little bit of cloudiness would settle out. Last week, I decided to rack again, and maybe bottle it.

During the racking, I took pains to avoid bumping the walls of the carboy with the auto-siphon, as fine particles had settled there. I also left avoided siphoning off the bottom inch (or so) of liquid, thus avoiding most of the fine sediment. The racked mead seemed to not have any visible particulates, although there was still a fine haze. I decided that it probably wasn't going to get much better by letting it sit for another half a year, so I went ahead and bottled. And, frankly, the minor haziness is something I can live with.


Minor haziness is most visible in full sunlight.

The final specific gravity was 0.994, slightly lower (but within experimental error) than the s.g. in January. Total yield was 14 bottles, plus another 300 mL or so that I put in the fridge for immediate consumption.

So, is it any good? Well, yes. This mead is far better than the my first attempt, which was made using some generic honey from Costco. This one has more interesting, complex honey flavours, and it tastes 'clean'. It is also very dry and it's delicious when chilled - a perfect summer treat.




Monday, 12 June 2017

Hops in the Garden

I am now growing hops in my garden. This is with the goal of eventually making beer directly from the four basic ingredients (water, barley, hops, and yeast), using fresh hops grown in my own garden.

The inspiration for this goal comes from a few places. It started with the 2014 book "The Perfect Keg" by Ian Coutts. This is a fun Canadian work of non-fiction in which the author documents his attempts to grow his own barley in order to make beer from scratch, at the same time learning various brewing tricks from master brewers. It's a fun read. Coutt's desire to start from scratch is something that I understand, and kudos to him for pursuing that.

For some time now, I have enjoyed a range of YouTube videos on home brewing. These have fired up my interest in all-grain brewing (i.e. starting from barley itself). At some point, I will post links to some of the more interesting videos I have seen.

In early May, my wife and I attended a free seminar on growing hops at the Enjoy Centre, here in St. Albert. The seminar was run in part by the proprietors of Northern Girls Hopyard. They even brought along some hop plants for sale. At that time, they only had Cascade and Centennial hops, which, I understand, are used mainly in brewing IPAs. So, I separately ordered two Golding hops plants from them and picked them up two weeks ago.

I re-potted the hop plants in large planters. Why not in the ground, you might ask? The answer is that I was warned by a friend who has previously grown his own hops that they basically start growing everywhere. Hops propogate through rhizomes (i.e. the roots grow and send up new shoots), which means that you need to manage them. Putting the hop plants in a container seemed like an easier option.


The Northern Girls recommend the use of twine for the hop 'bines'. This requires hanging the twine from some kind of overhead point of contact, which was not practical. So, I tried a bamboo pole instead of twine. Fortunately, the hops have taken to this perfectly, with a tiny bit of training at the beginning:

Hop plant growing clockwise up and around bamboo.
I'm looking forward to seeing how the hops turn out. They are certainly growing quickly.


Saturday, 10 June 2017

Czeck Pilsner & Red Ale

Over the last three months, I made two beers from kits. The first kit was a Czeck Pilsner wort kit by Festa Brew. The second was a Red Ale kit by Brewer's Best.

Festa Brew wort kits are quite easy, but I kind of wonder about the final quality given just how long the bags of pasteurized wort might be sitting on the shelf before you purchase it and take it home. When I bought this Czeck Pilsner kit from Estate Brewing in Edmonton, the owner told me that it was a very popular kit and his stock was being sold quickly. In the end, it turned out to be a nice beer, but I'm not convinced it's much like actual Czeck pilsners like Pilsner Urquell. The main difference, to me, is that the kit beer has much more citrus flavour.

Needing a new challenge just to keep my interest, the next kit I bought was an ingredient kit from Brewer's Best. The kit included malt extract, malted barley, freeze dried hops, yeast, priming sugar, and bottle caps. In order to make this beer, I also needed some new equipment - in particular a 6 gallon stainless steel kettle, which is basically a gigantic pot.

Brewer's Best beer ingredient kit.


This was the first time I have made beer from an ingredient kit, and it was a lot of fun. After the usual sanitization, the process consisted of bringing 3 gallons of water to 150 oF, steeping malted, crushed grains (in a bag), bringing the wort to a boil, adding liquid malt extract, and then adding two different types of hops (Golding and Willamette) at specific times. After the hops were added, their aromas began to fill the entire house, which resulted in my kids all separately asking, "what's that smell?" (Nobody was complaining, it's just that nobody had smelled anything like it before!)

The biggest challenge was trying to cool the wort down to room temperature after the boil. I had not invested in one of those coiled wort chillers, so I had to resort to taking the kettle outside and placing it in a pile of snow. (Yes, we get snow in April in Edmonton.) It took about 2 hours to get the temperature down to, which seems way too long. I need to buy a wort chiller.

After that, I added water to bring the total volume to 5 gallons, pitched the yeast, and the fermentation started up right away. After 3 days, the foam head had collapsed and I siphoned the beer into a carboy. After 12 days in the carboy, and noting that specific gravity was not changing, I proceeded to bottling. This meant transferring the beer to a large bucket, mixing in the priming sugar, and then filling and capping bottles.

Three weeks later, I tasted this Red Ale and I was floored. First of all, I have to characterize the taste as distinctly "fresh". There are just no off-flavours at all. For example, many commercial beers (especially from cans for kegs) have a metallic tinny taste that kind of ruins it. Other beers can develop skunky flavours that arise from photochemical reactions in the beer, especially when the beer is in clear bottles. And sometimes there are flavours that make me think the beer has just been sitting around too long. This beer came out fresh, and it's certainly fresher tasting than any of the beers I have made from wort kits.

Second of all, as described on the kit label, this beer is "smooth and easy drinking", a "balance of caramel malts and specialty grains", with low hop bitterness. I am not a fan of many IPA's, but I do enjoy beers that have complex caramel flavours that come from malted grains. So, this beer suits my tastes just about perfectly. I have told friends that this is the best beer I have ever tasted, which might seem like an exaggeration, but it's true for me. I will probably make this beer again, and it has me salivating over the possibility of making beer from your own malted grains.

Saturday, 14 January 2017

Peach Melomel - Tasting & Bottling

Three months have passed since I racked the peach melomel to let it clarify. Passive clarification was effective in this case. The melomel was crystal clear at the time of bottling.

I siphoned the melomel into a sterilized carboy, and stirred it vigorously for about ten minutes. This was to remove residual carbon dioxide. I actually did a taste test before and after stirring, and it was easy to detect the reduction in carbonation. I also took a specific gravity reading, and found it unchanged from the previous measurement.

Bottling was a snap. The three gallon batch is a good size for my purposes. This yielded 14 (and half) bottles in the end. Some volume is always lost in the racking, but that's fine.


Bottles of peach melomel.

I like the taste of this batch. The taste is light and reminiscent to some dry white wines. It has a mild honey aroma, and the honey taste seems most noticeable at the front and middle. Then, a gentle fruit flavour emerges at the end. The acidity is just right. But the odd thing is that I have a hard time identifying a peach flavour!

Fruit flavours come from organic compounds called esters, and the pure compounds have very specific tastes and aromas. One of the fun things about esters is that they are easily transformed into other esters, under certain chemical conditions. That means you can transform an ester with one particular flavour into another ester that has a totally different flavour. All you have to do is mix up the ester with a little acid and an alcohol compound (the alcohol that we drink is an alcohol known as ethanol).

So, here's one hypothesis: peach flavour comes from "linalyl" esters. In the presence of ethanol and acid, these could be converted to the corresponding "ethyl" esters. The ethyl esters in question are present in bananas, lemons, pineapples, and strawberries. When I sip this peach melomel, I taste hints of all of these. (Caveat: this is just a hypothesis.)

Another, perhaps more likely, scenario is that the peach linalyl esters decomposed into carboxylic acids, which do not have fruit flavours at all. :(

"Peach" Melomel. More like "Fruit" Melomel.


 

Monday, 2 January 2017

American Red Ale

Over the holiday break, I made a batch of beer from a kit. The "ReadyBrew" kit was manufactured by craft brewer Paddock Wood Brewing, Saskatoon (Hey, that's almost local for me!). According to the manager of the store where I bought it, Paddock Wood Brewing prepares fifty 23 L kits from every batch of their own beer. That's kind of cool!

The "kit" consisted of a boxed bag of 23 L of wort. That's all. (But, frankly, I didn't mind because nothing says 'serious' like a kit consisting of only one raw material. "You need to select your own yeast, buddy.")

A couple of days before Christmas, I started the fermentation. Within a day, there was quite an accumulation of foam - enough to push the lid off the bucket:

Uh oh!

While I didn't bother to take a picture of what happened next, I can assure readers that the foam created quite a mess, especially when it dried out. Fortunately, I put the entire primary fermentation bucket in a large plastic tub, which contained the mess. The excessive foam production did not last very long. Another day, and the foam had collapsed to a manageable level.

On Christmas Day, I took a few minutes to transfer the beer from into a sterilized carboy, and installed an airlock. And, today, January 2, 2017, I added priming sugar and bottled. I'm really looking forward to enjoying a bottle in a couple of weeks.

Happy New Year!

Tuesday, 8 November 2016

Fermentation Kinetics

Since I "re-started" the fermentation in the mead about three weeks ago, I have kept an eye on the fermentation rate. It seems to be going as one would expect: after the large increase in bubble rate over the first 2-3 days, the bubble rate has been decreasing slowly. As a chemist, in this sort of situation, I can't keep myself from taking measurements and recording them in a table. For many years, in all sorts of chemistry experiments, I measured and modeled chemical kinetics (i.e. the study of the rate of reactions). Here's what I found about the mead fermentation.

Method: Measure the number of airlock bubbles per minute, noting the time and date. Calculate the logarithm of bubble rate, and make a plot of this against time.


This is what is known as a "first order plot". It shows that the rate does not decrease linearly, but that the rate of decrease slows down with time. This is typical of reactions in which the rate depends on how much of the starting material, or reactant, is present. In the case of fermentation, the reactant is sugar. As sugar is consumed by the yeast, the rate of fermentation will obviously decrease. However, the decrease in rate is not linear - the "deceleration" slows down over time. In this type of reaction, when you make a graph of the logarithm of the rate vs. time, you get a straight line. That's what happened here.

Fermentation kinetics are actually a lot more complicated, especially at the beginning of the fermentation process, when yeast populations are growing, and the fermentation rate is accelerating. In this case, fermentation is almost complete and the yeast population is no longer growing. There are lots of yeast cells present, and the rate is only limited by the amount of sugar remaining. The result is "first order kinetics".

One day, I would like to try measuring the fermentation rate from start to finish, but it gets complicated. Measuring airlock bubble rate would be a pain during primary fermentation, when the rate is quite high. The other way you can measure the rate is by looking at alcohol content. The problem with alcohol content is that the measurement is in situ, requiring the insertion of a wine thief and hydrometer into the must. This increases the likelihood of introducing oxygen or microbes into the must.
  


Saturday, 15 October 2016

Stuck Fermentation

What is it about mead and stuck fermentation? If you google search "mead stuck fermentation", you find that this is a widespread problem for home mead makers. I recently had to deal with it in my most recent attempt at mead.

Back in August, secondary fermentation of this mead had more or less stopped. Things had been going pretty well, and I assumed that most of the sugar must have been used up by the yeast. As I noted in an earlier post, I broke my hydrometer and therefore had no quick way to measure the specific gravity. (Actually, I could have measured out a volume of mead and measured the mass, from which you can easily calculate density. I have a cute little jeweller's electronic balance that measures to 0.01 g.) So, without knowing the completeness of the fermentation, I racked the mead with the intention to let it age and clarify.

As the mead was "aging", I noticed that there was a constant, very slow rate of gas production in the carboy. In the meantime, the batch of peach melomel was getting to the end stage of secondary fermentation, and it was time to rack it. Last week, I decided to rack the melomel and the mead, checking the specific gravity of each using my new hydrometer. Here's what I found:

Peach Melomel s.g. = 0.990 (Conclusion: fermentation is complete, and it's time to let it age)

Mead s.g. = 1.038 (Conclusion: oh crap, fermentation is stuck)

So, I had to intervene. I added two Campden tablets (crushed and pre-dissolved), 1 tsp of yeast nutrient, and a packet of Lalvin EC-1118 yeast. Bubble formation seemed to pick up within a few hours. The next day, gas production still wasn't as fast I would like, so I raised the temperature in the room using an oil heater, and also added 2 tsp of yeast energizer. Yeast energizer has a slightly different nutrient mix as yeast nutrient. Three days later, the fermentation in the mead was chugging along nicely, and continues:

Gas production after kick-starting the fermentation
with yeast nutrients and higher temperature.
Did fermentation resume because of added nutrients for the yeast, the higher room temperature (from 17 up to 22 degrees C), or both? I don't really know, but I suspect it was mostly the nutrients. After all, the peach melomel, which presumably had more nutrients from the peach juice, seemed to work out fine in the relatively cool room in which I keep this stuff. Lesson for next time: add more nutrient, with the proviso that "yeast energizer" is likely the more effective.