Just learned what a SMASH recipe is, and I like the idea. Can it be done w extract?
short answer: kinda.
most extracts don’t contain just one type of base malt. many have carapils or others added for body or head retention. if you don’t mind the little extras in there, go for it.
The general philosophy of SMaSH is to simplify a recipe down to one malt and one hop to get a good picture of the flavor contributions of each. While technically most extracts aren’t made from a single malt (a few are - Northern Brewer’s Marris Otter extract is one.), you can still get a good picture of how that single extract type works with a single hop variety. If you are an extract brewer, this can be just as useful of a tool as a true SMaSH beer is to an all-grain brewer.
It might be a more useful tool for an extract brewer, considering you can also get a better idea of the fermentability of the extract, and the residual sweetness of your preferred extract. This will give you a good idea of how much crystal or such you want to add to your beer when you are attempting to reach that perfect style.
I have always thought that SMASH beers are really good for understanding ingredients. Sometimes the beer is great, most of the time it feels like its missing a bit of complexity.
Sure. Just use extra-pale, golden or pilsner extract.
You may not be able to try every possible base malt that way, but you can do some with research. Either way, single hop beers will be interesting.