Start by preparing the peppers. Using gloves, remove the stems and seeds of the cayenne peppers and discard.
Transfer the red cayenne peppers to a food processor. Add the white rice vinegar, water, and salt. Process for 2-3 minutes or until it forms a slightly chunky mixture.
Transfer the paste to two small glass jars (or a large one) and cover with a cheesecloth. Place in a dark place at room temperature. Let it ferment for 7 days, stirring every other day. After about three days you should already see some bubbles while stirring, this means the fermentation has started. The smell will also change, getting a sweeter, more pleasant one.
After 7 days, transfer the mixture to a high-speed blender. Blend on high-speed for about 1 minute. By blending once again we will get more liquid out of the peppers.
Strain the sauce using a fine mesh sieve over a bowl. Discard the pulp (or use in stir-fries, chili pastes, etc). Add the paprika and butter flavor to the sauce and transfer to a small bottle or clean jar.
Store in the refrigerator for up to 1 month. You can use this buffalo sauce as a marinade for tofu, seitan, tempeh, or use in dressing, sauces, etc!