From green bean to ice-cream: coffee ice-cream from scratch
I have been fairly quiet on the Triple Motion blog for a while now. I feel slightly embarrassed that I let life get in the way of a good cranking session and so as part of my mid-year resolution I am determined to make a mends. I was not really sure what flavour to go for to break the ice-cream famine so I went for something which is very close to my heart…coffee.
As a researcher who works in a university environment, coffee is an integral part of my day. In fact, I often muse that no science would ever get done if coffee was taken away from academics as it seems that the best ideas come up over a ‘cup o’joe’. Anyways, I am fairly particular about my coffee and try and maintain a certain standard. I have never drunk instant coffee and since at Christmas Dr Big D bought me a kick ass the best manual coffee grinder, there has been no stopping me. I usually buy my beans from a local coffee retailer who roasts on site daily and sells around 20 single origin varieties. I have been very impressed with their offerings but when the opportunity came along to take my coffee obsession to the next level, and roast my own beans, I jumped at the chance. I decided that this would be a perfect opportunity to get back into ice-cream making too…from green bean to ice-cream…let the adventure commence!
The coffee roasting
The coffee roasting master class was led by Alsino who is a friend of my house mate. He is an advocate of the ‘dog-bowl’ method which as beautifully rustic as it sounds. Essentially what you need is:
- A metal dog bowl
- A paint stripping heat gun
- A wooden spoon
- Around 200g of green coffee beans
The process then is pretty simple. Put the beans in the bowl (Honduras beans in this case), crank up the heat gun and get stirring. The trick is to hold the gun close enough to the beans to get them hot (3-5 cm is best) but not so close that they burn. You need to keep siring all the time so you get a nice even roast. Fairly soon, you start to get some smoke -this is totally normal but if indoors it could get a bit overpowering (go outdoors or near to an extractor fan). After about 5-10 min (depending on how close you hold the heat gun) the beans start to go a golden brown and shortly after that you hear the ‘first crack’. The best way to describe this is like popping corn. Once all the beans have ‘cracked’ everything goes quiet for a while and then you hear the ‘second crack’. This is a bit like the sound of a snapping match. At this stage we pulled out as we did not want a really deep, bitter flavour to develop but you can carry on until you start to see some oil form on the surface of the beans (see below). At this point you should defiantly stop or you will just get burnt beans. Once you have finished the roasting it is best to try and cool them down as quickly as possible. We did this by pouring them from the dog bowl into a colander a few times. 6-8 hours later (or less if you were impatient like me) they are ready for grinding and drinking.
NOTE: I was going for a Vienna roast suitable for espresso here but if you wanted something milder you could stop at the first crack (called City roast) or darker when the oil comes out (called French roast).
For the ice-cream it was the traditional Russell mix base:
- 2 eggs
- 1 cup of strong coffee (made in Bialetti)
- 2 cups cream
- Top up with full cream milk
As there were plenty of people on-hand the cranking was over pretty quickly and before we could say cappuccino it was ready.
The flavour was pretty good and the texture nice and smooth. I think it could have coped with a bit more coffee maybe but then I am addicted so I would say that!