Rhubarb is a high quality ingredient that can make a great, age-worthy wine. It’s also a versatile ingredient that shines in many different styles. To take advantage of its versatility, you need to know what it brings to your wine and what you need to add.
Sugar and acidity of rhubarb juice
So what does a winemaker need to know about rhubarb? The short answer is sugar and acid. Getting that right is the biggest part of any successful recipe. It turns out that rhubarb has a lot of acid and not much sugar. I juice the rhubarb and normally see measurments like this (these figure are from my most recent batch):
specific gravity (SG): 1.020, titratable acidity (TA): 14 g/L as tartaric, pH: 3.19
This agrees with Ben Rotter’s data:
SG: 1.020, TA: not enough data, pH: 3.17
Most of that acid, 70% or more, is malic.
A lot of people make rhubarb wine by fermenting on the fruit, and most recipes specify the amount of rhubarb by weight. To make sense of these recipes, or make wine with whole fruit, or to compare notes with other wine makers, you’ll need to know how much juice a given weight of rhubarb will yield. I got 515 ml (17.4 fl oz) of juice from 1.115 kg (2.5 lb) of fruit, or a yield of 462 ml/kg (7 fl oz/lb).
I froze the rhubarb, thawed it in a strainer and got 225 ml (7.6 fl oz) of “free run” juice. Then I lightly pressed, just squeezing with my hands, to get another 290 ml (9.8 fl oz). This is low compared to Mr. Rotter’s data (470 – 830 ml/kg). The pulp I discarded was wet, so I could have gotten more with a small press.
You know your own procedures better than I do. Do you efficiently squeeze the fruit leaving bone-dry pulp? Expect over 600 ml/kg (9.2 fl oz/lb). If you press lightly and leave wet pulp, then you’re more likely to get 500 ml/kg (7.7 fl oz/lb), give or take. Now we have some information on yield, sugar, and acidity. What can we do with these data?
The possibilities are endless
I normally make my rhubarb wine dry, and I can tell you it’s terrific that way. I’ve tasted sweet rhubarb wine that was fabulous. I’ve aged rhubarb wine over two years and noticed improvement. I’ve tasted 5+ year old rhubarb wine from the Montana Hutterites that was superb. I’ve heard that the Hutterites successfully age their wine for decades, and Ben Rotter aged a sweet rhubarb wine for 30 years, and it hadn’t past it’s peak. Many wine makers have found rhubarb to be an excellent blending wine.
This is what I mean when I say that rhubarb is versatile. That’s why no recipe can show you “what rhubarb wine tastes like”. To find out, you need to go beyond any one recipe and try different variations. Honey instead of sugar, sweet instead of dry, dry instead of sweet, high acid like a Riesling – and do set some bottles aside for extended ageing! While we’re on the subject of ageing, I wouldn’t recommend rhubarb as an early drinker. Even if you decide against extended ageing, you’ll want to give it at least a year.