I made two very close to identical one gallon batches. They both had the same amount of speciality grains seeped, although one had about 2 more ounces of DME.
One batch I seeped at around 155 for 15 minutes which turned out much darker than the second batch. The second batch I seeped for 15 minutes from about 100 degrees up to about 175.
Can the temp affect how much color I'll get from grains?