Baratza Vario Grinder woes

[GotGoodCoffee?]

Hi, still trying to figure out best grind setting with the baratza vario and my MiniV2. So far all the shots taste bitter and are absolutely undrinkable. I've tried macro at 1, 2, 3 and various degress of micro adjustments. Been trying to replicate feel of sugar but seems tricky. Been using beans from stumptown and counter culture. Not sure if there is a good initial setting to start with on the vario and then go from there? Any help will be appreciated. Thanks.

[chas]

So long as you're not over-extracting; i.e. grinding so fine that the shot is going way beyond 25s, bitter usually means the group temperature is too high for the coffee you are using. Once you have the grind in the right ballpark for the 25-35s shot time, try one shot a 90C, one at 92C, and one at 94C so you can see the flavor differences due to temperature. Some coffees have a wide range of temperatures over which they taste good and other have to be right on the money.

[algrilli]

Chas' points are spot on, as usual. You should start there.

I don't have the Vario, so I can't give you grinder parameters, but i do use the coffees you mentioned and I like them sweet. Here are the parameters that work for me:

CC Toscano: 14.5g @ 93C. Dark chocolate, sweet.
CC Rustico: 14.5g @ 94C. Dark chocolate, sweet, black cherry notes. Raising temp tames the fruit, eg. 93C is WAY too fruity for me.
Stumptown Hairbender: 15.5g @ 95C. Smooth and balanced with milk chocolate notes. 93C was really sour.

Also, for sweet shots, I have found:
- Temp plays a big role in flavor. Generally I find: temp too low = sour and temp too high = bitter. Also, dark beans need a lower starting temp and lighter beans need a higher starting temp. Again, that's in general.
- Watch the pour. I've seen my barista pulling Hairbender - he doesn't go past about 20-23 seconds.
- The "2oz in 25 seconds" advice doesn't work for me - that's way too fast for way too much coffee. Bitter. Esp since I don't use that much coffee. See next bullet.
- The Spaz does not like overdosing. It needs headroom. I never believed that, but after six years, I'm now a convert. For years, I was doing the "overfill portafilter and simply level it off with finger" method, but Ive found that's still too much for the Spaz and it's a waste of beans. It'll work, but 14 - 16g seems to really come through for me.
-Hope that helps!

[GotGoodCoffee?]

Thank you for your suggestions. I'm going to give it a try and see what happens. I didn't realize changing the temp could matter that much.