Hi guys, I have messed around with Brewer's Friend quite a bit and it is really nice. I used to use Beersmith 2, but found it looked a little outdated even if it is a nice application. I prefer web applications myself. Anyway, I have some questions I am hoping someone can help clear up. I have a Cooper's plastic fermenting vessel which can do 23l brews (oh, yeah, I'm dealing with metric as well because I am from Australia). I have started moving away from pre-hopped tins and going extract, with hopes of going all-grain by the end of the year. To do a 23l brew, I have some questions as to what values I should put into the editor. Admittedly, I am a noob when it comes to extract brewing. So forgive me if these questions have obvious answers. For batch size, what do I put here if I want to do brews of a maximum 23l? I occasionally do 21 litre brews and sometimes even small batches as well. Does this value take into account that you will be topping up the fermenter with water alongside the boiled wort? So if I am doing a 21 liter IPA, (combined total of wort and top up water) I put in a batch size of 21 liters? Then my final question is boil size. I am not sure what the general rule of thumb is here for boiling. I have a 20l stock pot, so I can probably do a maximum of 15l in it to account for any boil over, maybe ideally around the 12 liter mark to be honest. How am I supposed to know the boil size or does it not matter? I notice that the boil size affects the IBU's and gravity, is it simply a matter of finding a boil size that achieves my desired bitterness and gravity? The boiled extracts give me the wort that I would usually buy in a pre-hopped can, correct? I could not see any mention for extract brews of top-up water being accounted for. I assume Brewer's Friend can see my batch size, my boil size and automatically knows I am topping up with water (or do I need to tick something somewhere?). I currently have an APA recipe which has a batch size of 23l, target set to fermentor and boil size 11.5l. Achieving an OG of 1.049, FG of 1.012, ABV of 4.91% and IBU of 37.47. Does this seem alright?