I'm making a witbier this weekend that calls for 1 tsp of coriander added to the boil at 2 minutes. I'm wondering if I should purchase seeds and grind them myself, or just buy a jar of ground coriander off the spice rack. Anyone have any experience they could share on which would be better? Thanks in advance!
I buy whole coriander and use a mortar and pestle to crack the shells before adding it to the boil. Whole coriander keeps longer and will give a fresher aroma than pre-ground.
To grind it at home, a coffee grinder would probably be overkill. You only need to break the shells. If you don't have a mortar and pestle, you can use a meat tenderizing hammer (or even a regular hammer). Just put the whole coriander in a plastic bag, wrap it in a towel and tap it evenly. You don't want to turn it to dust as that makes it more difficult to filter out.
Also it would be better to weigh the spices rather than use a teaspoon. A teaspoon of whole coriander versus a teaspoon of ground coriander can be very different by weight. 1 oz (28g) per 5 gallon batch is a common quantity.