BISMARCK, N.D. (AP) — North Dakota's wine industry has seen an unusually productive harvest despite severe drought conditions this summer.

The Bismarck Tribune reports that grapes grown in the state are cold-climate varieties, but heat allows the grapes to ripen faster.

Randy Albrecht is the operator of Wolf Creek Winery in Coleharbor. He says grapes that are used to create wine need to reach a certain sweetness and sugar level called brix. A brix level of 22.5 will make wine about 12 percent alcohol.

The state's grapes are usually more acidic, but as the grapes ripened, the acid dropped and they became sweeter.

The state's wine industry is expected to continue its rapid growth. That's causing some concern that there isn't enough fruit being grown commercially to meet demands in the future.