Picked Müllet Thurgau grapes today, advice welcome

[Mumathomebrew]

My friend had me round this afternoon to help her pick some grapes (in a UK garden). There were more than we thought. 19 kilos+ (42.5lbs) of Müller Thurgau very ripe grapes.

I'm thinking Lalvin QA23 to bring out the fruity flavours and enhance the Germanic aspects.

I've looked them up to see what treatment might suit this grape the best. It seems this grape gets accused of being dull and without character. Quite understandable by tasting the grapes themselves. They are certainly soft and sweet without much acidic character. The skins are tough and non tannic. The insides are flabby, watery and pippy. Not a very interesting grape to eat.

It appears this grape is the one responsible for the likes of Blue Nun and Black Tower so you see where this could go if some action isn't taken.

From looking through ten finished wines and seeing what they've done, it seems that often stainless steel tanks under pressure are mentioned. Possibly trying to extract as much as possible from not much in the first place perhaps. Keeping on the lees is mentioned too. Both fermenting on and off skins is also done. Aromas and flavours mentioned are nutmeg, apples and peaches.

The softness will be fun to enhance to maybe achieve a creamy venous quality. The body will need attention and probably acids added for some poignancy. It's a matter of quite how to achieve this. I was thinking tea for tannin and some tartaric acid perhaps. I'm not sure about adding sultanas for body as they can make the finished wines taste sherryish to me. I have got some other sharper grapes but they are acidy tart and I don't want to spoil these soft grapes.

There are enough to try a few ways as I think these grapes will make three gallons-ish.

I would welcome some thoughts.

 

[shelly_belly]

Lalvin QA23 sounds good. Lalvin W15 was isolated from Müller Thurgau must so it may be worth a try. I have not used either.

 

[Mumathomebrew]

Thank you. I searched google for the worlds best rieslings to see what sort of thing to aim for, and it appears the prizes go to the sweeties. On this list is an ice wine, so maybe that is an answer. To ferment to balanced sweetness then concentrate. I've never done that before so it could be a fun leaning curve.

https://www.wine-searcher.com/m/2018/03/the-worlds-best-rieslings

https://www.wine-searcher.com/m/2017/06/the-world-s-most-wanted-rieslings

I then am looking up each wine to see what the vineyard do with them....

F E Trimbach Riesling Clos Sainte Hune says for instance that they do not wood barrel them to not offset the grape characters. It also suggests the juice is clarified before fermentation and not done on skin.

All sorts of clues to be gleaned. I don't normally have real grapes to play with, and especially not so many. I'd love to make something more special than my normal country bumpkin fruit and fine weed flower wines.

 

[Mumathomebrew]

Interesting quest for Lalvin W15 in the UK. It's not easy to find here it seems. QA23 it might have to be.

 

[Mumathomebrew]

Started these with four separate portions of 10.5lbs of grapes for each gallon method. Grapes washed and sterilised on stalk with campden, then removed and crushed by hand. SG was 1.052.

1) QA23 yeast for boosting the fruitier aspects +campden +pectolase. Boosted the acidity with 5g tartaric acid and 2g yeast nutrient. (I don't have an acid kit yet to be more accurate). The demi overflowed through the fermentation lock as I'd overfilled it, so it had to get dumped in a plastic bucket. I hope this hasn't already over-oxidised it. I wanted to watch it through the demi glass, and leave the skin on for a longer time in this version but the narrow neck forced the grapes through. Predictable really.

2) D47 to improve mouthfeel +campden +pectolase. No acid boost. Also overflowed and moved to bucket.

3) QA23 +campden +pectolase. Put in two demis not one. Might boost acid but will taste later to see. Made up a solution of 1pt water to 1lb sugar and added half to each.

For this version, thinking of artificially 'boosting' all the attributes displayed as advantages in the best commercial wines, using a weak solution of the appropriate ingredients. Might use micro amounts of real nutmeg, pears, apples and gooseberries but not sure whether to do that yet as I rarely get real grapes to play with. I might mock that idea up with a grape juice later.

4) A sweet dessert version intended. Have introduced "Mockrytis' Noble Rot to improve the flavour intensity using my slow, low heat aga plate warming oven with the door left open. So far have left the grapes in there for two days and rearranged them now and again to get the pale green grapes on top. I may ruin them, but if I've left them whole, then they should be fine. It might lose lots of aroma but will gain in sweetness. I've been testing them regularly to make sure they're not ruining. They're out of the oven now on day three/four and are drying out on the warm top. I expect wine purists are squirming by now. When they're sweet enough then maybe a fast yeast. Not sure which yet, but my best flower dessert wines have been made with young's dessert yeast or youngs 'champagne' yeast. I'm not sure they make that one anymore as I've only found 'sparkling' and I'm not sure if it's the same yeast.

We'll see what happens. Such fun to have so many real grapes to play with. Especially ones that aren't as respected because it means less fear of ruining them. More terrifying if they were a fabulous grape.

If anyone has fabulous ideas, then I'm open to suggestion because I know very little about using grapes. What frightens me is making a sour, thin plonk. Even making a Blue Nun-alike would be a success if it's drinkable. That wine has a dreadful reputation over here as a 1970/80's party wine, but it wasn't that bad or it wouldn't have been so popular.

Mockrytis pic.

 

[Mumathomebrew]

Moved the first three to secondary last night. It was all very splashy and messy from buckets into jam nets so I hope I haven't completely ruined them with air. Pics taken last night straight afterwards and then again this morning.

The two made with QA23 smelled exactly like blue nun. The one without extra sugar the most. Very funny. The D47 didn't though, so it will be interesting to see the difference later. Not sure what to top them up with. Don't want to spoil the experiment by supplementing with other grape juices.

Then lobbed all the, by then very well aired, grapes back in the bucket with 11oz sugar and four litres of water. They can take their chances now.

The mockrytis version is bubbling away still on grape.

 

[Seamonkey84]

If there’s still an active fermentation you should be fine with that headspace, but the splashing should be avoided after the first 3-4 days. I’d recommend getting some mesh bags to put fruit in when using buckets. When you want to remove fruit, just gently pull the bag out and squeeze it till it’s not dripping anymore. Then rack to secondary vessels. When you rack those again, try using a 3L Carlo Rossi style bottle, or save some wide mouth glass juice bottles.

 

[Mumathomebrew]

Definitely need mesh bags for fruits and hops. I rarely use the buckets because I prefer to see what's going on but they're very useful with lots of solid matter in the brew. I splashed these far too much because I could barely lift them to pour well. Wine was flying everywhere because the half squished grapes had filled up again with must and squirted nicely when I squeezed them. One very sticky kitchen. I bunged in lots of campden to try to counteract that but have probably shocked the yeasts now. The left one is very quiet. I'm just wondering if I'll completely spoil the purity if I top up with a sugar/water. The SG was a bit low anyway, making about a 7% ish wine which won't protect it enough either. I know that sugar addition is wrong for proper grape wine but does it matter if it saves the brew?