From: C.V.Copas@lut.ac.uk
Newsgroups: rec.crafts.brewing
Subject: Re: Meads:  Brewing/Drinking/Headaches...
Date: 12 Aug 92 11:03:44 GMT
Reply-To: C.V.Copas@lut.ac.uk (Conn Copas)
Organization: Loughborough University, UK.

In article <22813@hacgate.SCG.HAC.COM> abirenbo@pollux.cel.scg.hac.com (Aaron Birenboim) writes:
>
>what is "sulpheric"?  like as in sulpheric acid?  i guess we could conver this
>into a molarity of sulpheric, and then calculate for the appropriate
>molarity of....  say.... tartaric or citric or ascorbic, no?  My chemistry
>is quite rusty.
>
Exactly. I have a book containing these conversion tables. It is just a 
standard way of specifying the acid content.
>
>grape tannin.....  tannic acid no?
>
Right, but as with all brewing additives, watch out for purity and mixtures if
the quantities concerned are small.
>
>available from tea also, i think.
>Unfortunately the one recipe using tea called for something like
>"2 tbsp of nice strong tea for 5 gal".  not very scientific.
>my mead books are mostly useless.
>
This thread prompted me to go and read Acton & Duncan last night, which
addresses all this stuff, and more. They recommend an acidity of 2.5-3.5 ppt
sulphuric, which is slightly lower than for wine. They don't specify a 
standard unadjusted level for mead, but they do recommend adding 1/2-3/4 oz of
acid blend per Imp gall. Another of their books states that 1/4 oz per Imp gall
of most organic acids will raise the acidity by 1.0, which corresponds with my
experience. The implication therefore is that mead typically has a very low
natural acidity, which the taste buds can confirm. They recommend a 2:1 mixture
of malic and tartaric as being most appropriate for mead, but don't give a
reason. Malic acid is characteristic of apples and pears, whereas tartaric acid
is the major component of grape juice. Ergo, fruit meads are bound to have a 
better natural balance. Apples, pears and elderberries all contain considerable
tannin. Otherwise, the recommendation is 2g tannic acid per Imp gall.

They reluctantly advise that the juice of 2 lemons and 1 tablespoon of very
strong tea, per Imp gall, can emulate the above additions.

Now for the interesting part. Acid deficiencies are said to cause off-flavours
of the medicinal sort, presumably referring to phenols, as well as reducing
resistance to infection. Which suggests to me that people should maybe
reconsider some of the anti-nutrient sentiment which seems to inhabit this
list, which has always seemed slightly bizarre to me. A&D recommend a 
combination of ammonium salt (as a nitrogen nutrient) and vitamin B1 (as an
energiser); the alternative being to wait 8 years for maturation! I 
must admit that I never had problems with nutrient off-flavours, and I would be
extremely nervous if any primary ferment took longer than 3 weeks. Alcohol
content can be increased by feeding the yeast with 4oz/gall increments of
honey, late in the fermentation.

While I'm on controversial issues, why boil all your aroma away? Sure,
sterility is important, and I can see how people might have reservations about
sulphiting, but remember that cider and wine makers have traditionally got
away with no sterilisation of the must, on a commercial scale. The reason that
brewers can't do this is because the environment is different : low acidity and
low alcohol. I've made wine from 12 month old frozen apples, some of which were
windfalls, with no sterilisation and no ill-effects. In that sort
of situation, I do get concerned about lag times, so I pitch a vigourous,
sterile, starter and aerate the must thoroughly (and use nutrient, and adjust
the acidity). There is a post in HBD suggesting that unboiled honey contains 
enzymes which inhibit yeast. IMHO, pitching yeast into inhospitable 
environments is the bigger inhibitor.