So I started out with a beer that was 1.126 SG with about 3.3 gallons. Then I pitched a 2 liter starter (with 200 grams of DME) that was at high krausen into the wort. No idea what the starter gravity was when i pitched it. My hydrometer says it is now an OG of 1.098 rather than the starting 1.126 that I measured earlier. I'm sure that there is a way to calculate the OG based on the SG of the 3.3 gallons of wort and the 2 liters of starter wort, but I'm apparently not smart enough to figure it out...but I'm sure someone on this forum has already ran into this problem and solved it. So the questions are: What is the correct SG? Roughly how much alcohol was already present in the starter? How can I calculate this again the next time as this is a batch I do every month?