Just for clarity, I use JD BBQ Chips and not the JD chips sold by HBS which I found were a complete ripoff. I had stopped using them for a while but got an opportunity to buy a bulk amount and took it. I got them for one Euro a bag that's about 82p to you in real money

The bags weigh around 800g I use two bags of these, after rinsing and steaming, in 20lt of neutral spirit. This makes a very passable anyday Whisky good for sipping or mixing.
You said you could only get 100g of chips in the jar but you could remove some spirit from the jar to make room for more chips. If you do, then keep the removed spirit in a jar and, when you filter the spirit off the chips for bottling, you can add the removed portion back in.

If you're going to use JD BBQ Chips I recommend 2.125lt on 200g for 10 days and give your jar a good shake every day and it will look like this...

...and taste like mmmmmmmmmm!
Filter through cotton wool in a funnel to remove any wood particles or dust that may be in the spirit then enjoy.
AM
