Monday, November 12, 2012

Of Worts and Boils

As I mentioned in my last post, I spent Friday brewing. It feels great to be back in the swing of it and having carboys fermenting away with much abandon in the cellar. I am still getting to grips with my new(ish) setup and equipment though and I have missed my target gravity in 2 out of the last three brews, the third being an extract beer, which is pretty easy to get within a few gravity points of the target.

For the first time in a while, I had an assistant brewer for the day, one of my colleagues from the Starr Hill tasting room who wanted to learn more about brewing. She also took the pictures in this post, as well as performing vital tasks like holding the grain bag while I tried not to give her third degree burns with the strike water. Having an assistant certainly made the process a lot easier and made me realise that when I return from my exile to the mythical land of 47% I really need to get my setup sorted in the garage, preferably with as much gravity involvement as possible.

The beer itself turned out to be an Export strength Oatmeal Milk Stout, rather than the Imperial Oatmeal Milk Stout I initially wanted to brew. However, with a starting gravity of 1.062 (15.2° Plato) and projected ABV of 6% it should have enough oomph to keep the darkness at bay during the winter.

As I said earlier, I have missed my target gravity on the last couple of brews I have done, a fact that I put down to a couple of things. Firstly I am now doing whole wort boils rather than diluting a smaller boil, and also I have a new 5 gallon cooler mash tun rather than the small 2.5 gallon affair I used previously. Part of me wonders if I am getting a good enough mix in my mash, so I plan to buy a new, longer handled spoon for stirring the mash to get an even blend of grain and water. Secondly, I think I am simply not sparging enough, and thus leaving a fair whack of sugar in the mash rather than in the wort.

On Friday I had about 4 gallons of wort for my 2.5 gallon batch and after a 90 minute boil, just barely had the required volume left, so maybe an extra gallon or so of wort and a 2 hour boil would make all the difference?

So, my fellow brewers, any thoughts and/or input as to how to get back to the world of 75% efficiency in my setup?


  1. Wetter mash, slower run off help at work and liquor treatment worked with my home brew.

  2. My efficiency was all over the place when I first moved up to my current 10 gal cooler mash tun, but after lots of trial and error I was able to get up to a pretty consistent 72%. The first thing I did was shell out about $30 for a new thermometer -- I realized my old one, dead-on at freezing and boil, was off at 150 F. That solved most of my problems, but I was still inconsistent in my calculations of how much strike water I would need to hit the desired mash temp. I took a friend's advice and started pre-warming the cooler. I'll boil about a gallon of water and pour it in the mash tun about half an hour before I'm ready to mash, close it up, and dump it just before adding the grain. For whatever reasons of thermal dynamics, this has lead to consistent strike volume calculations, which makes every other calculation a whole lot easier.

    1. I agree with Chris. Preheating the mash tun makes a huge difference when trying to hit your mash temps. When I was having some issues a while back I stepped away from single infusion mashing. Instead I started following the formula John Palmer outlines in How to brew for step mashing. Using a spread sheet to do the math, all I really need to know is how much boiling water to add and I can be pretty close to spot on without having to rely on a thermometer as much.