Prepare your berries. I use blackberries as the main bulk, and these just need a quick wash. Remove any stalks from the haws, halve the rosehips and scrape out the inner and then wash them all thoroughly. Sloes are best picked after the first frost, but as the devil supposedly spits on blackberries on September 29th and you shouldn't pick them after this, pop the sloes in the freezer overnight and this will have the same effect, helping the skins to soften and split.
Sterilize a large 1.5 litre kilner jar, either by warming it in the oven, or by putting it in the dishwasher on a hot cycle (lazy I know, but it seems to do the trick).
Layer the berries and sugar in the clean jar, then top up with vodka.
Shake every day for 7 days to dissolve the sugar, then store in a cool dark cupboard for 3 months, before straining through a muslin and bottling. I tend to give it a little taste now and then, just to see if I need to adjust the sweetness and add more sugar.
Haws can cause a sediment if left for over a month, so if you are doing a purely hawthorn vodka I would strain it after 4 weeks then continue to store the liquid until it matures. However just a handful doesn't seem to make the schnapps too murky if you do leave it for the full three months, and if it is a little cloudy you can always strain it through a coffee paper to clear it.
Drink in tiny glasses as a lovely winter evening treat!