So far I’ve used dried packet quick yeasts but things have gone a lot better since I started using fresh bakers’ yeast from Sainsbury’s. I buy 200g at a time from the in-store bakery and then divide it into teaspoon sized bits that weigh about 7g each and then I freeze them in a plastic tub. This quantity has lasted me about 3 or 4 weeks a time so far. One counter assistant was a bit more generous and I got 280g which lasted me a bit longer. I have started reading the River Cottage Handbook 3 for bread and it says that yeast shouldn’t be frozen because it dies more often than it lives. I can’t say I have had any problems with keeping these tiny pieces for a few weeks so maybe there’s a limit to when they should be used.
Anyway, when I make bread I pop the required number of teaspoon pieces into the warm water or other liquid and let it melt and mix it in before adding anything else. It’s also possible to cut these small pieces with a sharp knife if a recipe only needs half a teaspoon of yeast. Dan Lepard says that one teaspoon of fresh yeast is the same as one teaspoon of dried yeast, so his recipes are really easy to convert.
Here’s a picture of what this looks like: