We decided to consolidate our payment options when we made the switch to recurring billing. We did quite a bit of research and we selected Stripe as our payment processor due to their security practices as well as their support for developers. You can find more information on their site here: https://stripe.com/
or more technical information on security: https://stripe.com/docs/security/stripe
Stripe is completely secure, and the way it works it does not allow us to store any credit card or billing information whatsoever on our servers. That information goes directly to Stripe and we simply receive a token that allows us and only us to bill your card. So even if Brewer's Friend is completely hacked (let's hope not), no one can compromise your credit card.
Please let me know if you have any further questions.