For fun, I tared the empty 1-cup basket that comes with the BDB, slightly overfilled and tamped it, trimmed it back with the BDB's Razor tool, and re-weighed. I was surprised to find it holds right around 14.0g, rather than the nominal 10g for a 1-cup basket.

I find when I use a grind setting that produces a ~30 second, 14g liquid extraction (1:1 ratio), I get a pretty full-bodied, sweet, and flavorful result that I like. I'm not sure if this qualifies as a true ristretto (1:1) since it involves a non-standard amount of coffee in a 1-cup basket.

I think my main point was lost, let me try again. I thought (sure I read it somewhere) that a 2-cup basket was 20g and 1-cup was 10g on the BDB. But when I filled the 1-cup basket and used the BDB Razor tool to trim it back (presumably, what Breville designers would say the optimum level is) I was surprised it came out to 14g, not 10g. Maybe it's a 14g basket after all?



Then, when I extracted, the shot would start nice and dark but transition quickly to blond at some point not far past 14g. But when I simply stopped at 14g (1:1) I liked the result.

I suspect not many had explored the single thus the lack of response. I did this on my Portaspresso Rossa with 55mm single basket(7g) and had similar observation.

I dosed about 15-16g in a supposedly 7g basket. The shot blonds quicker at shorter brew ratio, compared to the typical straight-sided double basket. Despite the quicker blonding, the updosed 'single' shot is non-faulty - full of flavor/clarity and is softer, despite the shorter brew ratio. It's completely different from a double-basket ristretto, which is intense, mouth-coating body but with less flavor clarity and more edgy. Measured using refractometer, the extraction yield from these updosed single is typically about 13-15% instead of 19-21% yielded on the double basket.

Like you, I found it very enjoyable and is not replicable using the double basket.

Thanks! Exactly the kind of technical answer I was hoping for, which I find interesting. Instead of pulling doubles all the time it will be nice to have this as an option, and stretch my coffee a little further too.