Watery Thin beer - 2 attempts at BIAB, sad face

[liquidman]

I normally use 4-5kg of grain per 22l brew, as Vally Commando says: your grain bill seems a bit short on the sweet stuff -to get what your aiming for.

A

[orlando]

I reckon your grain bill is a little low for 16L into the fermenter. I do full length BIAB and have settled at 4.5-5kg of grain giving 26L into the FV, you have less grain per litre of liquor. Now if you have a very efficient mash that may be OK, but my guess is your mash is likely to be average, same as mine (Biab methods considered to have lower efficiency mash than 3V as a rule of thumb.)

So either up the grain bill, or reduce your dilution and you should have a higher OG wort to work with which will likely give a less watery result. Oh and allow plenty of conditioning time as the others said, CO2 is a huge mouthfeel component!

I reckon this is the root of the problem of thinness. I don't do BIAB but recognise the issue of a low grain to liquour ratio. I suggest you play around with this in your software. The lack of condition issue can only be down to temperature as you are right when you say 1tsp per 500ml is usually enough if not more than usual. You need to ensure that temps are consistently around the 18c mark for the initial conditioning period then a consistently cool period to allow the CO2 to dissolve into the beer. I use BeerSmith2 as my software and it tells me exactly how much sugar to use for priming for any given volume of CO2 I'm looking for, but it insists I store at 18c for it to work.

You also complained about a lack of head retention, which I don't think anyone else has addressed. Two things with this, you could incorporate some torrified wheat in your grain bill, even 2 or 3% would be enough. Second and one I fall down on many times, is ensure your glass is squeeky clean and you are not eating fatty food when you drink. It's amazing how you can kill the head with either of these things not being right.