Hi, I've just made some mincemeat with some tesco's Finest beef stock. The packet of 600ml was 4.8g of carbs. I had to reduce it quite a lot to get the flavour.
(It's liquid by the gravy, boullion etc. It's shelf life is about a year)
Hope this helps, it is difficult to find a stock that tastes like you're used to. Hopefully it will be worth it