low abv wine

[summer shed]

I'm a 1st. timer. I made some wine from jam following exactly CJJ Berry's recipe. The tem of the fermenter was 26-28 on the heat strip. Started at 1.090 and ended at 1.040. How can I make it stronger. I added re-start yeast at 1 gram per gal but no change.
Thanks in advance for any advice

 

[salcoco]

stir the must a few times a day. add some yeast nutrient.

 

[wpt-me]

I did one using Smucker's brand Blackberry. Was able to get it to 1.014 using two additions of nutrient/energizer
and making a starter.

Bill