>>>No business, no tax. Simple as that.
>>
>>Lucky you has not the germsn equivalent of IRS to cope with.
>>Their base assumption is everything not drunk by you, your immediate family or at your table is not tax free - it might be a gift aka bribe.
>
>So what, if I visit an old friend whom I haven't seen in years, if I bring a bottle of my own as a gift, it's taxable?

If you had any biz connection with him, yes - which is not that far fetched - recipient has to pay tax on it.
And they might "ask" you to provide list of recipients - if not provided, will assume you sold part of the stuff.
Not totally unrealistic, as drinking all that for yourself is rather unlikely.

Is that 90l per still or per person operating it ? Do you rent out your still if not using it yourself ?
(mentioning tax sets mind into automatic loophole searching mode...)