In ayurveda you can't describe it according to acidic or alkaline nature, ayurvedic medicines and ingredients work differently, rasa of some medicines are different and when vipaka happens inside the body it becomes different.

Amla is definitely Amla in nature but causes pitta supression! Due to its cold nature! Ginger pepper are katu (pungent) And bitter ( tikta ) in nature causes excellent light up of agni that's digestive fire! Honey is kashaya A stringent in nature causes loosening of cough! AYURVEDA has a concept of " CONVERSION " OR PARINAMAN" it means a particular kind of food changes its properties after entering into the body! Pippali( piper longum) is katu tikta in nature so should reduce sperm count in body as katu tikta ras increases vata And decreases kaph( increasing kaph is responsible for increasing sperm count as both are of Same guna) But Pippali works by vipaka( conversion into madhur ras) after entering into body hence Increase sperm count!

Happy learning curve. Keep it up

We need to know constitution

There is no classification as acidic and alkaline in ayurveda.Ayurveda classify drugs according to rasa,Guna,veerya,vipaka, prabhava.Acid and alkali are ushna guna,both have Agni bhootha in it's constitution. Pepper ginger,cardomom, pepper mint,mint,  honey are ushna.Amla  aloevera   may be sheeta guna.action is not always guna, sometimes with rasa, some times with veerya, sometimes with vipaka and sometimes with prabhava.If any doubt may contact me.

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