You should pour your chopped rhubarb and sugar into a large bowl, then mix them together. Then place a towel loosely on top of your mixture to sit overnight. You should stir no more than twice during this period. Make sure to evenly distribute your sugar until it settles at the bottom.

It's a new day. Be sure to add your lavender sprigs then give your mixture a stir before you place it in your fridge. You might want to use a half gallon jar to decant your mixture before you put it in your fridge. You can carry on with your daily routine or skip town for no longer than 6 days.

If you're too excited to wait for 6 days, you can leave your mixture in the fridge for just over 24 hours. Once your timer hits, you can grab your chinois or fine-mesh colander. You want to strain your mixture carefully while avoiding any spills. Next, you should place your mixture in the fridge overnight. Don't forget to give it an occasion stir if you see any sugar that might be sitting at the top.

It's the last step of your recipe preparation. You can discard your solids and add more apple cider vinegar to your remaining liquid. Now, whisk it until it's smooth. Thereafter, you can pour it into your bottles or jars for storing it in your fridge.

You should consider letting your bottled mixture chill in your fridge for a good week if you want to intensify your flavors. The thing is, your vinegar is just like wine; it gets better with time. The tanginess should mellow out to allow the fresh and fruity blends of lavender and rhubarb to amplify. The great news is that you can keep your mixture in your fridge for up to three months without worrying about any changes to its flavor. In addition, the cold temperature helps to maintain your apple cider vinegar's acidic levels.