Q: Question for the Canadian Barista Institute: What do you think of this old Scottish Recipe? We figure it was written in the early to mid 1900's, due to the recipes we found them with. I may have mis-read ’sock’ as ’sack’. Maybe they used socks and liked the tasting notes of old socks and toes… They were Scottish, after all!
A: Very cool, we love seeing these old recipes and it has technical veracity. First of all the ratios are pretty much the same as we use now. 60 grams (2 ounce) of coffee for 1 quart and a half pint (1.18 liter) of water, that is approximately 60-75 grams per liter.
I think it says a coffee ‘sack’. There is some history of a cotton sack being used for coffee, not to worry, we don’t need to think about using an old pair of argyle socks.
It’s a good thing the brew time is only 3 minutes long because they are instructing you to boil the water , which leads to more over extraction than we would like, but it's within a reasonable range.
The egg is far more interesting. It shows up in many cultures where an egg would be put in a pot of coffee or a French press. I believe the initial intent of the egg was to clarify the brew.. much like how a chef clarifies or clears a stock by using a raw egg to form a net which captures impurities in a stock, making it clearer . Egg has been used to clarify beers I believe in a similar manner.
Putting the egg in the sack with the coffee is a little strange because the bag does the clarifying by itself, being a filter. So I think this is the morphing of the egg clarifying technique.
As for the eggshells … it's calcium carbonate which in theory would neutralize some of the acid in the coffee so for our third wave taste we would probably omit the eggshell.
So if you want to try it .. follow the recipe but without the sock or sack. But instead use a French press pot, let the water cool , do not use boiling water, and crack an egg over top. You won't have any grounds when you pour !
Your Scottish Grandma would not have had a new-age percolator, so this would have been cooked over a wood or coal burning cast iron stove, which is why the egg is used to clarify the brew because she wouldn’t have had a filter.