Hi! Just got email from Kayleigh ordering me to read this thread!
I've already made mine. It's an annual ritual for me, and some of my friends and relatives will already be waiting for Christmas to come so they can collect their bottle!
The best container to use is a wide-mouthed plastic demijohn with a screw-cap, but any large jar or crock will do. Take at least 1lb of sloes. The old-fashioned way is to prick them all over with a large needle, but that takes hours, so I put them into a food processor in small batches and whizz them to cut into the surface a bit.
Put them in your container, add 4 oz sugar and 2 pints gin (cheapo is fine). Seal and shake the container to dissolve the sugar. Leave in a cool dark place for 3 months, giving the container an occasional shake. Then strain and bottle.
Be warned, the sloe juice is very very messy. Every utensil that touches it will be stained and the stains won't wash out, you have to wait for them to wear off. The juice is really glutinous and sets like superglue. Cover your worktop with an old sheet or newspapers and wipe up/wash up spills immediately.
I also made a batch of blackberry gin. Make it the same way but no need to blitz the berries. Easier and quicker than sloe gin and also yummy.