Hi there stryk,
Let's see if we can get you under way but first a couple of points that might help you and many others...
The best way to understand any software is to really spend concentrated time on it so you actually can understand how it works. This definitely takes time and a good knowledge of the brewing process. I suggest duplicating and renaming some of the sample recipes and equipment profiles, playing with them as much as you can and then comparing the recipes side by side so as you can see what's occurred. Unless you understand the software, it is impossible to take full advantage of it and you can also make serious errors when converting recipes from other sources.
BeerSmith2 assumes you already know your equipment so it can be hard to set your equipment up initially. You also need to understand that home brewers are brewing beer on a 'nano' level so it is very easy to get measurement discrepancies from brew to brew. What you need to do is several brews, say 5, and take as many measurements as you can during these brews. This will give you an average that you can modify as your experience and number of brews grow.
Your problem though is, "How do I get started?"
You've already given lots of info needed but some of this is unclear...
You mentioned you are aiming for "20 L batches when bottling." Be careful what terminology you use. Batch size in BeerSmith refers to the 'Volume Into Fermenter' not 'Bottling Volume'. Your pot is unlikely to give you 20 L of bottled beer. In fact, I am going to be working on a 19 L 'Batch Size'.
The first thing I am going to do is look for a Sample Equipment Profile that I think will closely match your urn and then I am going to change some figures. The closest equipment I can see is the 'Electric Urn (10 Gal/40L) - BIAB'. The fact it says 'BIAB' does not matter.
So, I'm going to copy and paste that and rename it 'Electric Urn (7 Gal/27L) - All-Grain'
This profile is very cautious, it allows for lots of trub and this is a good thing for beginners. But you have some experience with your kettle so we can reduce some things without risk. Let's have a look...
1. Boil Volume: This exceeds your urn size. We'll sort this below...
2. Boil Length: We can reduce this to 60 minutes though some waters/grain will produce cloudy beer etc on a 60 minute boil. I am going to change this anyway to a compromise of 70 minutes. This gives 10 minutes for your boil to settle before adding bittering hops.
3. Boil Off: Your urn has a smaller diameter than a 40 L urn so its boil off will be less. I'm guessing that the pot height and diameter are equal. A 27 L square-sided pot will have a diameter of about 32.5 cms. I've written the following formula to help predict evaporation rate based on kettle diameter...
Litres per hour = pi x (0.5 x diameter)2 x 0.00428
Using this formula, I am predicting your boil off will be 3.55 L / Hr. We are using a 70 minute boil so 70/60*3.55=4.14 L. This is the figure we will use.
4. Loss to Trub and Chiller: I am changing this to the 2 L you specified.
5. Top Up Water: As your Boil Volume was still too high, I am going to add 'Top Up Water' of 1.5 L. You can add this at the end of your boil instead of into your fermenter as this will help chill the beer and should avoid the need to boil the top up water.
6. Brewhouse Efficiency: This is very hard for a new all-grainer to work out. For example, your 'efficiency into kettle' or 'mash efficiency' will be lower as you will be using top up water so your grain will not be getting 'rinsed' in as much water but you have less 'Loss to Trub and Chiller' than the original profile so this increases your efficiency into fermenter which is BeerSmith2's, 'Brewhouse Efficiency'. I have used a spreadsheet to work out that your Brewhouse Efficiency should be set at about 69%. This can be hard to get your head around
.
7. Lauter Tun Deadspace: I am going to make this 0.95L.
This profile should get you under way but it is important to do those 5 brews and not let the measurements from a single one affect your judgement. I know from experience that the above profile will get you in the ballpark which is all that is necessary (and possible) when learning new equipment.
Later, you can adjust the figures but be careful. For example, you can't just reduce 'Loss to Trub and Chiller' without also changing your 'Brewhouse Efficiency.'
I hope the above helps you and a few others out as it is impossible for any of is to write such long posts every time this very good but very hard question comes up ;D.
So there's lots to learn stryk. Best of luck!
I'll keep an eye on this thread so if you have any more questions fire away. I'm not doing anyone else's profile for them though - lol!
Pat
Here is the profile...
